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IRIS-13

13th International Symposium on Inorganic Ring Systems

29th July – 2nd August 2012

at Delta Victoria Ocean Pointe Resort, 45 Songhees Road, Victoria, British Columbia

V9A 6T3, Canada

http://web.uvic.ca/~iris13

Program and Abstracts

IRIS occurs every three years and is the premier international showcase for Main Group Chemistry, including Organometallic Chemistry and Inorganic Materials Chemistry. The IRIS meetings bring together leading professors, postdoctoral fellows and research students from around the world.

The History of IRIS

Year Town Country Host/Chair IRIS-1 1975 Besancon France H. Garcia-Fernandez IRIS-1b 1977 Madrid Spain H. Garcia-Fernandez IRIS-2 1978 Göttingen Germany O. Glemser IRIS-3 1981 Graz Austria E. Hengge IRIS-4 1985 Paris France H. Garcia-Fernandez IRIS-5 1988 Amherst Massachusetts, USA R. R. Holmes IRIS-6 1991 Berlin Germany R. Steudel IRIS-7 1994 Banff Alberta, Canada T. Chivers IRIS-8 1997 Loughborough UK J. D. Woollins IRIS-9 2000 Saarbrücken Germany M. Veith IRIS-10 2003 Burlington Vermont, USA C. Allen IRIS-11 2006 Oulu Finland R. S. Laitinen IRIS-12 2009 Goa India P. Mathur

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Welcome Welcome to the 13th International Symposium on Inorganic Ring Systems and welcome to Victoria, BC. UVic is honoured to be hosting and sponsoring the premier international forum for Main Group Chemistry. The IRIS-13 conference provides an excellent opportunity to foster national and international collaboration in this important research field. Chemistry plays a fundamental role in many of UVic’s research strengths, across a number of disciplines. Our highly successful and internationally-recognised faculty and students in the UVic Department of Chemistry are excited to be given the opportunity at IRIS-13 to showcase their work and build on their mission of fostering world-class research and outstanding chemical education. I hope you have a wonderful time with us in Victoria. Dr. Howard Brunt Vice-President Research University of Victoria Welcome to IRIS-13 and beautiful Victoria. We are delighted to present an outstanding scientific program that will be augmented by the picturesque setting of the inner harbour and the Olympic mountains. The program begins with a mixer on Sunday evening at the Royal BC Museum, offering a fascinating experience of native art and displays with an array of culinary delights. The scientific oral presentations are scheduled for Monday, Tuesday, Wednesday morning and Thursday, with poster sessions on Monday and Tuesday evening. I am grateful for the advice and support of my colleagues on the International Advisory Board, the National Advisory Committee and the Local Organizing Committee during the development of this exciting program. We are grateful to the Delta Victoria Ocean Pointe Resort and Spa, our host for IRIS-13, for their partnership in the organization of IRIS-13. The Delta will serve a buffet lunch for all registrants on Monday, Tuesday and Thursday, and will host the symposium banquet on Thursday evening. Wednesday afternoon is designated as free time to give you an opportunity for outdoor activities including golf, hiking, sailing, fishing, sight seeing and whale watching. Alternatively, the downtown offers numerous sightseeing options within walking distance, and a wide selection of shops, restaurants and bars. We are especially grateful for the financial support of the sponsors who have made this event possible. Enjoy, N Neil Burford Symposium Chair Chair, Department of Chemistry University of Victoria

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The organizers acknowledge the generous support of the following Sponsors:

John Wiley & Sons

MBraun Incorporated USA

Department of Chemistry

Department of Chemistry

Department of Chemistry Faculty of Science Office of the Vice President Research Office of the Vice President Academic and Provost

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IRIS International Advisory Board

C.W. Allen (USA) H.W. Roesky (Germany) T. Chivers (Canada) R. Streubel (Germany) A.H. Cowley (USA) N. Tokitoh (Japan) R.R. Holmes (USA) F. Uhlig (Austria) R. Laitinen (Finland) M. Veith (Germany) J.P. Majoral (France) R. West (USA) P. Mathur (India) J.D. Woollins (UK)

IRIS-13 National Advisory Committee

Kim Baines (Western) Tom Baker (Ottawa) Thomas Baumgartner (Calgary) René Boeré (Lethbridge) Glen Briand (Mount Allison) Tris Chivers (Calgary) Jason Clyburne (Saint Mary's) Adam Dyker (New Brunswick) Bobby Ellis (Acadia) Chuck Macdonald (Windsor) Jason Masuda (Saint Mary's) Jack Passmore (New Brunswick) Kathryn Preuss (Guelph) Paul Ragogna (Western) Jeremy Rawson (Windsor) Eric Rivard (Alberta) Roland Roesler (Calgary) Doug Stephan (Toronto) Ignacio Vargas-Baca (McMaster)

IRIS-13 Local Organizing Committee

Neil Burford (Victoria), Symposium Chair Derek Gates (UBC) Robin Hicks (Victoria) Scott McIndoe (Victoria) Lisa Rosenberg (Victoria)

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IRIS-13 Schedule of Events at a Glance

Sunday 29 July Monday 30 July Tuesday 31 July Wednesday 1 August Thursday 2 August

8:30

Registration Registration Registration Registration 8:40 Welcome 8:50 Chlupaty Jaekle Piers 8:50 Liu, S-Y Wisian-Neilson 9:00 Bertrand 9:00 A O19 B O20 P5 A O37 B O38 9:10 P1 Sasamori Knight Fischer Vargas-Baca 9:20 A O21 B O22 A O39 B O40 9:30 Saito, M Mailman Reed 9:30 Macdonald Uhlig 9:40 Bourissou 9:40 A O23 B O24 K7 A O41 B O42 9:50 K1 West Tokitoh Ruzicka Less

10:00 A O25 B O26 Weigand 10:00 A O43 B O44 10:10 Laitinen 10:10 Percival Knapp K8 Neilson Baker 10:20 K2 A O27 B O28 A O45 B O46 10:30 Coffee Coffee Coffee 10:40 Coffee 10:30-10:50 10:30-10:50 10:30-10:50 10:50 10:40-11:00 Saito, S Rivard Aldridge 10:50 Hayward Moya-Cabrera 11:00 Dehnen 11:00 A O29 B O30 K9 A O47 B O48 11:10 K3 Liu, C-W Price Boere Jancik 11:20 A O31 B O32 Frenking 11:20 A O49 B O50 11:30 Sekiguchi 11:30 Mori Passmore K10 Masuda Jurkschat 11:40 P2 A O33 B O34 A O51 B O52 11:50 Tacke Dielmann Hey-Hawkins 11:50 Roesler Hasken 12:00 A O35 B O36 P6 A O53 B O54 12:10 Lunch 12:10-1:40 Lunch 12:10-1;40 Lunch 12:10-1:40 12:20 Delta Hotel Delta Hotel Delta Hotel 12:30 Harbour Room Harbour Room Free Time Harbour Room 1:40 Beckmann Omae Braunschweig 1:40

Jones 1:40 1:50 A O1 B O2 P3 P7 2:00 Scheer Gross 2:10 A O3 B O4 2:20 Rautianen Schulz Cummins 2:20 Ragogna 2:20 2:30 A O5 B O6 K4 K11 2:40 Preuss Gudat 2:50 A O7 B O8 Baines 2:50 Gabbai 2:50 3:00 Registration Wahler Chivers K5 K12 3:10 Delta Hotel A O9 B O10 3:20 Foyer Coffee Coffee Coffee 3:30 3:20-3:40 3:20-3:40 3:20-3:40 3:40 von Haenisch Townsend Scheschkewitz 3:40 Wright 3:40 3:50 A O11 B O12 K6 K13 4:00 Streubel Leitao 4:10 A O13 B O14 Power 4:10 Driess 4:10 4:20 Chakrahari Wolf P4 P8 4:30 A O15 B O16 4:40 Wazir Baumgartner

4:50 A O17 B O18 Closing Remarks 5:00 Poster Reception A Poster Reception B Reception 5:00

5:10 5:00-7:30 5:00-7:30 6:30 Mixer, Museum Delta Hotel Delta Hotel Banquet, Delta Hotel

6:30-9:30 Harbour Room Harbour Room 6:30-9:30

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Registration, Lunches and Social Events Registration: Sunday 29 July, 3:00-6:30 p.m. Monday 30 July, 8:00-8:40 a.m. Tuesday 31 July, 8:30-8:50 a.m. Wednesday 1 August, 8:30-8:50 a.m. Thursday 2 August, 8:30-8:50 a.m.

at the Delta Victoria Ocean Pointe Resort, Foyer Opening Mixer: Sunday 29 July, 6:30-9:30 p.m.

at the Royal BC Museum Lunch: Monday 30 July, 12:10-1:40 p.m.

at the Delta Victoria Ocean Pointe Resort, Harbour Room Lunch: Tuesday 31 July, 12:10-1:40 p.m.

at the Delta Victoria Ocean Pointe Resort, Harbour Room Lunch: Thursday 2 August, 12:10-1:40 p.m.

at the Delta Victoria Ocean Pointe Resort, Harbour Room Banquet: Thursday 2 August, 6:30-9:30 p.m.

at the Delta Victoria Ocean Pointe Resort, Ballroom

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Plenary, Keynote and Oral Contributions in the Ballroom

Monday 30 July 9:00 a.m. – 12:10 p.m. Plenary and Keynote Presentations Session Chair: Robin Hicks, University of Victoria Plenary 1: Guy Bertrand, UCR/CNRS, University of California, Riverside, USA (9:00 a.m.) Keynote 1: Didier Bourissou, Université Paul Sabatier, France (9:40 a.m.) Keynote 2: Risto Laitinen, University of Oulu, Finland (10:10 a.m.) Keynote 3: Stefanie Dehnen, Philipps-Universität, Marburg, Germany (11:00 a.m.) Plenary 2: Akira Sekiguchi, University of Tsukuba, Japan (11:30 a.m.) Lunch: at the Delta Victoria Ocean Pointe Resort, Harbour Room (12:10-1:40 p.m.) 1:40 p.m. – 5:00 p.m. Oral Contributions Session Chairs: Room A - Charles Macdonald, University of Windsor

Room B - Glen Briand, Mount Allison University

1. Jens Beckmann, Bremen University, Germany (A-1:40 p.m.) 2. Iwao Omae, Omae Research Laboratories, Sayama, Saitama, Japan (B-1:40 p.m.) 3. Manfred Scheer, University of Regensburg, Germany (A-2:00 p.m.) 4. Uwe Gross, Graz University of Technology, Austria (B-2:00 p.m.) 5. Mikko Rautiainen, University of Oulu, Finland (A-2:20 p.m.) 6. Axel Schulz, University of Rostock, Germany (B-2:20 p.m.) 7. Kathryn Preuss, University of Guelph, Canada (A-2:40 p.m.) 8. Dietrich Gudat, Universität Stuttgart, Germany (B-2:40 p.m.) 9. Johannes Wahler, Julius-Maximilians-University Würzburg, Germany (A-3:00 p.m.) 10. Tristram Chivers, University of Calgary, Canada (B-3:00 p.m.) 11. Carsten von Hänisch, Philipps-Universität-Marburg, Germany (A-3:40 p.m.) 12. Nell Townsend, University of Bristol, UK (B-3:40 p.m.) 13. Rainer Streubel, Rheinische Friedrich-Wilhelms Universität Bonn, Germany (A-4:00 p.m.) 14. Erin Leitao, University of Bristol, UK (B-4:00 p.m.) 15. Kiran Kumar Varma Chakrahari, IIT Madras, India (A-4:20 p.m.) 16. Robert Wolf, University of Regensburg, Germany (B-4:20 p.m.) 17. Hameed Ullah Wazir, Hazara University Mansehra, Pakistan (A-4:40 p.m.) 18. Thomas Baumgartner, University of Calgary, Canada (B-4:40 p.m.)

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Plenary, Keynote and Oral Contributions (continued) in the Ballroom

Tuesday 31 July 8:50 a.m. – 12:10 p.m. Oral Contributions Session Chairs: Room A - Rene Boere, University of Lethbridge

Room B - Lisa Rosenberg, University of Victoria

19. Tomas Chlupaty, University of Pardubice, Czech Republic (A-8:50 a.m.) 20. Frieder Jäkle, Rutgers University, USA (B-8:50 a.m.) 21. Takahiro Sasamori, Kyoto University, Japan (A-9:10 a.m.) 22. Fergus Knight, University of St Andrews, UK (B-9:10 a.m.) 23. Masaichi Saito, Saitama University, Japan (A-9:30 a.m.) 24. Aaron Mailman, University of Waterloo, Canada (B-9:30 a.m.) 25. Robert West, University of Wisconsin, USA (A-9:50 a.m.) 26. Norihiro Tokitoh, Kyoto University, Japan (B-9:50 a.m.) 27. Paul Percival, Simon Fraser University, Canada (A-10:10 a.m.) 28. Carsten Knapp, Bergische Universität Wuppertal, Germany (B-10:10 a.m.) 29. Shohei Saito, Nagoya University, Japan (A-10:50 a.m.) 30. Eric Rivard, University of Alberta, Canada (B-10:50 a.m.) 31. Chen-Wei Liu, National Dong Hwa University, Taiwan (A-11:10 a.m.) 32. Jacquelyn Price, Western University, Canada (B-11:10 a.m.) 33. Takao Mori, National Institute for Materials Science, Tsukuba, Japan (A-11:30 a.m.) 34. Jack Passmore, University of New Brunswick, Canada (B-11:30 a.m.) 35. Reinhold Tacke, Julius-Maximilians-University Würzburg, Germany (A-11:50 a.m.) 36. Fabian Dielmann, University of California, Riverside, USA (B-11:50 a.m.)

Lunch: at the Delta Victoria Ocean Pointe Resort, Harbour Room (12:10-1:40 p.m.) 1:40 p.m. – 4:50 p.m. Plenary and Keynote Presentations Session Chair: Tom Baker, University of Ottawa

Plenary 3: Holger Braunschweig, University of Würzburg, Germany (1:40 p.m.) Keynote 4: Christopher Cummins, Massachusetts Institute of Technology, USA (2:20 p.m.) Keynote 5: Kim Baines, Western University, Canada (2:50 p.m.) Keynote 6: David Scheschkewitz, Saarland University, Germany (3:40 p.m.) Plenary 4: Philip Power, University of California, Davis, USA (4:10 p.m.)

Wednesday 1 August 8:50 a.m. – 12:30 p.m. Plenary and Keynote Presentations Session Chair: Derek Gates, University of British Columbia

Plenary 5: Warren Piers, University of Calgary, Canada (8:50 a.m.) Keynote 7: Christopher Reed, University of California, Riverside, USA (9:30 a.m.) Keynote 8: Jan Weigand, Westfälische Wilhelms-Universität Münster, Germany (10:00 a.m.) Keynote 9: Simon Aldridge, University of Oxford, UK (10:50 a.m.) Keynote 10: Gernot Frenking, Philipps-Universität, Marburg, Germany (11:20 a.m.) Plenary 6: Evamarie Hey-Hawkins, Universität Leipzig, Germany (11:50 a.m.)

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Plenary, Keynote and Oral Contributions (continued) in the Ballroom

Thursday 2 August 8:50 a.m. – 12:10 p.m. Oral Contributions

Session Chairs: Room A - Thomas Baumgartner, University of Calgary Room B - Jason Clyburne, Saint Mary’s University

37. Shih-Yuan Liu, University of Oregon, USA (A-8:50 a.m.)

38. Patty Wisian-Neilson, Southern Methodist University, USA (B-8:50 a.m.) 39. Roland Fischer, Graz University of Technology, Austria (A-9:10 a.m.) 40. Ignacio Vargas-Baca, McMaster University, Canada (B-9:10 a.m.) 41. Charles Macdonald, University of Windsor, Canada (A-9:30 a.m.) 42. Frank Uhlig, Graz University of Technology, Austria (B-9:30 a.m.) 43. Ales Ruzicka, University of Pardubice, Czech Republic (A-9:50 a.m.) 44. Robert Less, Cambridge University, UK (B-9:50 a.m.) 45. Robert Neilson, Texas Christian University, USA (A-10:10 a.m.) 46. Tom Baker, University of Ottawa, Canada (B-10:10 a.m.) 47. John Hayward, University of Windsor, Canada (A-10:50 a.m.) 48. Monica Moya-Cabrera, Universidad Nacional Autónoma de México, Mexico (B-10:50 a.m.) 49. Rene Boeré, University of Lethbridge, Canada (A-11:10 a.m.) 50. Vojtech Jancik, Centro Conjunto de Investigación en Química Sustentable, Mexico (B-11:10

a.m.) 51. Jason Masuda, Saint Mary's University, Canada (A-11:30 a.m.) 52. Klaus Jurschat, Technische Universität Dortmund, Germany (B-11:30 a.m.) 53. Roland Roesler, University of Calgary, Canada (A-11:50 a.m.) 54. Bernd Hasken, Graz University of Technology, Austria (B-11:50 a.m.)

Lunch: at the Delta Victoria Ocean Pointe Resort, Harbour Room (12:10-1:40 p.m.) 1:40 p.m. – 4:50 p.m. Plenary and Keynote Presentations Session Chair: Tristram Chivers, University of Calgary

Plenary 7: Cameron Jones, Monash University, Australia (1:40 p.m.) Keynote 11: Paul Ragogna, Western University, Canada (2:20 p.m.) Keynote 12: François P. Gabbaï, Texas A&M University, USA (2:50 p.m.) Keynote 13: Dominic Wright, Cambridge University, UK (3:40 p.m.) Plenary 8: Matthias Driess, Technische Universität Berlin, Germany (4:10 p.m.)

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Contributed Poster Presentations in the Harbour Room

Poster Session A, Monday 30 July, 5:00 p.m. – 7:30 p.m.

1. Jason Clyburne, Saint Mary’s University, Canada 2. Klaus Dück, Julius-Maximilians-University Würzburg, Germany 3. Thomas Kramer, Julius-Maximilians-University Würzburg, Germany 4. Katharina Ferkinghoff, Julius-Maximilians-University Würzburg, Germany 5. Johannes Brand, Julius-Maximilians-University Würzburg, Germany 6. Rong Shang, Julius-Maximilians-University Würzburg, Germany 7. Christian Hörl, Julius-Maximilians-University Würzburg, Germany 8. Pravin Likhar, CSIR-Indian Institute of Chemical Technology, India 9. Michal Horáček, Institute of Physical Chemistry of Academy of Sciences, Czech Republic 10. Alexander Villinger, University of Rostock, Germany 11. Michael Feierabend, Philipps-Universität Marburg, Germany 12. Christian Bimbös, Philipps-Universität Marburg, Germany 13. Koh Sugamata, Kyoto University, Japan 14. Krista Morrow, University of Victoria, Canada 15. Emma Nicholls-Allison, University of Victoria, Canada 16. Hisashi Miyamoto, Kyoto University, Japan 17. Antonín Lyčka, University of Pardubice, Czech Republic 18. Roman Jambor, University of Pardubice, Czech Republc 19. Libor Dostál, University of Pardubice, Czech Republic 20. Guoxiong Hua, University of St. Andrews, UK 21. Masaichi Saito, Saitama University, Japan 22. Louise Diamond, University of St. Andrews, UK 23. Laura Forfar, University of Bristol, UK 24. José Manuel Villalba Franco, Rheinische Friedrich-Wilhelms Universität Bonn, Germany 25. Johanna Flock, Graz University of Technology, Austria 26. Petra Wilfling, Graz University of Technology, Austria 27. Eliza ter Jung, Philipps-University Marburg, Germany 28. Bastian Weinert, Philipps-University Marburg, Germany 29. Vojtech Jancik, Centro Conjunto de Investigación en Química Sustentable, Mexico 30. Thomas Zöller, Technische Universität Dortmund, Germany 31. Andreas Nordheider, University of St. Andrews, UK and University of Calgary, Canada 32. Phillip Elder, University of Calgary, Canada 33. Jonathan Dube, Western University, Canada 34. Elizabeth MacDonald, Dalhousie University, Canada 35. Jens Eußner, Philipps-Universität Marburg, Germany 36. Alexandra Slawin, University of St. Andrews, UK 37. Stewart Lucas, University of Victoria, Canada 38. Yi-Chou Tsai, National Tsing-Hua University, Taiwan 39. Takuya Kuwabara, Saitama University, Japan 40. Derek Woollins, University of St. Andrews, UK 41. Glen Briand, Mount Allison University, Canada 42. Jamie Ritch, University of Winnipeg, Canada

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Contributed Poster Presentations (continued) in the Harbour Room

Poster Session B, Tuesday 31 July, 5:00 p.m. – 7:30 p.m.

43. Peter Lee, University of Victoria, Canada 44. Beatrix Barth, Philipps-University Marburg, Germany 45. Christoph Bolli, Bergische Universität Wuppertal, Germany 46. Mathias Keßler, Bergische Universität Wuppertal, Germany 47. Thao Tran, University of Windsor, Canada 48. Khatera Hazin, University of British Columbia, Canada 49. Jan Turek, University of Pardubice, Czech Republic 50. Teemu Takaluoma, University of Oulu, Finland 51. Roman Olejnik, University of Pardubice, Czech Republic 52. Aino Eironen, University of Oulu, Finland 53. Kazuhiko Nagura, Nagoya University, Japan 54. Minna Karjalainen, University of Oulu, Finland 55. Timothy King, University of Cambridge, UK 56. Tomokatsu Kushida, Nagoya University, Japan 57. Paresh Kumar Majhi, Rheinische Friedrich-Wilhelms Universität Bonn, Germany 58. Arturo Espinosa, Universidad de Murcia, Spain 59. Josef Binder, Graz University of Technology, Germany 60. Andrew Priegert, University of British Columbia, Canada 61. Hugh Cowley, University of Windsor, Canada 62. Justin Wrixon, University of Windsor, Canada 63. Christopher Allan, University of Windsor, Canada 64. Krzysztof Radacki, Universität Würzburg, Germany 65. Tom Hsieh, University of British Columbia, Canada 66. Zdenka Padelkova, University of Pardubice, Czech Republic 67. Dominik Naglav, Universität Duisburg-Essen, Germany 68. Christian Hering, Universität Rostock, Germany 69. Thomas Wilson, University of Cambridge, UK 70. Lucia Myongwon Lee, McMaster University, Canada 71. Adrian Houghton, University of Calgary, Canada 72. Melina Klein, Rheinische Friedrich-Wilhelms Universität Bonn, Germany 73. Saurabh Chitnis, University of Victoria, Canada 74. Glen Briand, Mount Allison University, Canada 75. Glen Briand, Mount Allison University, Canada 76. Benjamin Rawe, University of British Columbia, Canada 77. Johann Pichler, Graz University of Technology 78. Jonathan Dube, Western University, Canada 79. Joseph West, University of North Dakota, USA 80. Mónica Moya-Cabrera, Universidad Nacional Autónoma de México, Mexico 81. Rene Boeré, University of Lethbridge, Canada 82. Vojtech Jancik, Centro Conjunto de Investigación en Química Sustentable, Mexico 83. Thomas Zöller, Technische Universität Dortmund, Germany 84. Sarah Dane, University of Cambridge, UK

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Stable Carbenes for the Stabilization of Organoboron Lewis Bases, Phosphino Nitrenes, and for the Activation of P4

Guy Bertrand

(guy.bertrand@ucr.edu) UCR/CNRS Joint Research Chemistry Laboratory, University of California, Riverside, CA, 92521, USA

Amines and boranes are the archetypical Lewis bases and acids, respectively. We will discuss the synthesis of neutral tricoordinate boron derivatives A, which act as Lewis bases giving B, and undergo one-electron oxidation into the corresponding radical cations C. Compounds A, B and C are borylenes (R-B:), borynium (R2B+) and borinylium (R-B+.), respectively, stabilized by two carbenes.[1] Transition metal nitrido (or metallo nitrene) complexes LnMN have attracted considerable attention due to their implications in biological nitrogen fixation by the nitrogenase enzymes, the industrial hydrogenation of N2 into NH3, exemplified by the Haber- Bosch process, and more generally for catalytic nitrogen-atom transfer reactions. We will discuss the synthesis and reactivity of the first stable non-metallic nitrene.[2] Lastly, recent results concerning the carbene activation of white phosphorus will be discussed.[3]

[1] R. Kinjo, B. Donnadieu, M. Ali Celik, G. Frenking, G. Bertrand, Science 2011, 333, 610-613. [2] F. Dielmann, O. Back, M. Elinger, G. Frenking, G. Bertrand, 2012, unpublished results. [3] D. Martin, M. Soleilhavoup, G. Bertrand, Chem. Sci. 2011, 2, 389-399 [4] For the coordination and activation of -bonds at coinage metals, see: a) P. Gualco, S. Ladeira, K.

Miqueu, A. Amgoune, D. Bourissou, J. Am. Chem. Soc. 2011, 133, 4257; b) P. Gualco, S. Ladeira, K. Miqueu, A. Amgoune, D. Bourissou, Angew. Chem. Int. Ed. 2011, 50, 8320.

Plenary 1

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Coordination of Lewis Acids and -Bonds by a Chelating Approach: Towards Original Metallacycles

D. Bourissou

(dbouriss@chimie.ups-tlse.fr) Université Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée

118 route de Narbonne, 31062 Toulouse cedex, France

Over the last few years, our group has been studying the coordination properties of ambiphilic ligands.[1] Our approach consists in using donor groups, typically phosphines, to support original metal / ligand interactions. This strategy was first used to investigate the coordination of Lewis acids as -acceptor ligands (metallacycles of type A).[2] We are now extrapolating this approach to the coordination and activation of inert -bonds (metallacycles of type B).[3] In this presentation, recent examples of both types will be discussed. Particular attention will be devoted to the structure of the isolated metallacycles that will be analyzed on the basis of spectroscopic, crystallographic and computational data.

[1] For a review on the coordination of ambiphilic ligands, see: G. Bouhadir, A. Amgoune, D. Bourissou, Adv. Organomet. Chem. 2010, 58, 1.

[2] For a review on -acceptor ligands, see: A. Amgoune, D. Bourissou, Chem. Commun. 2011, 47, 859.

Keynote 1 1

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Cyclic Imido-Selenium and -Tellurium Compounds and their Transition Metal Complexes

Risto S. Laitinen,a Aino Eironen,a Raija Oilunkaniemia and Tristram Chivers b

(risto.laitinen@oulu.fi) a Department of Chemistry, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland, b Department of

Chemistry, University of Calgary, 2500 University Drive N.W., Calgary, Alberta, T2N 1N4 Canada Recent progress in the chemistry of imido derivatives of selenium and tellurium is discussed in order to provide understanding in the unusual features of their structures, bonding, and reactivities. Structural trends are considered by including also comparisons with related sulfur-nitrogen compounds, where appropriate (for a recent review, see ref. 1). Cyclic sulfur imides form a well-characterized class of compounds the most common examples being the eight-membered ring molecules S8-n(NH)n. While the corresponding selenium and tellurium imides are unknown, some organic derivatives have been prepared and structurally characterized.

Se3(NAd)2

Se3(NtBu)3 Se6(NtBu)2 Se9(NtBu)6 Te3(NtBu)3 The coordination chemistry of selenium and tellurium imides is also described. Metal complexes of selenium(IV) and tellurium(IV) diimides are exclusively N,N’-coordinated, whereas cyclic selenium imides behave as chelating Se,Se’-donor ligands.

[HgCl2{tBuNTe(µ-NtBu)2TeNtBu}]

[CoCl2{tBuNTe(µ-NtBu)2TeNtBu}]

[PdCl2{Se4(NtBu)3}] [PdCl2{Se4(NtBu)4}] [PdCl2{Se(NtBu)2}] [PtCl2{Se(NtBu)2}] [1] Laitinen, R.S., Oilunkaniemi, R., Chivers, T., in Woollins, J.D., Laitinen, R.S. (ed.), Selenium and

Tellurium Chemistry: From Small Molecules to Biomolecules and Materials, Springer Verlag, Berlin 2011, pp. 103-122.

Keynote 2 1

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"Take 2": An Elegant Approach To Multinary Metallates and Intermetalloid Clusters

Stefanie Dehnen

(dehnen@chemie.uni-marburg.de) Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften, Philipps-Universität

Marburg, Hans-Meerwein-Straße, D-35032 Marburg, Germany

Multinary, non-oxidic metallates are currently actively investigated by many research groups, leading from structural studies through functional analyses to the generation of innovative materials.[1] Binary main group element aggregates proved to be useful synthetic tools for a large variety of different structural and functional motifs.[2]

Whereas chalcogenido-tetrelate/trielate ions [TxChy]q– (T = Ge, Sn, In; Ch = S, Se, Te) may be basically viewed as heavier homologues of silicates or borates, the inversely polarized pnictogene-tetrelide/trielide ions [TxPny]q– (Pn = Sb, Bi) have a distinct tendency to form intermetalloid clusters.[3] However, in both cases, the products of reactions with further metal M compounds differ significantly from any lighter homologues, as they represent unprecedented, ternary clusters or networks, according to the general type [MxTyChz]q–, [(RT)xMyEz] (R = functional/bridging organic ligand) or ternary Zintl anions [MxTyPnz]q–. The physical properties of the compounds, which may represent (photo-)semi-conductors, ion conductors or bond-activating nano-capsules, are dependent on the nature of the involved elements and the observed structure type.[4–6] Ionothermal techniques were successfully applied recently for the synthesis of novel salts of such complex anions.[7]

[1] P. Feng, X. Bu, N. Zheng, Acc. Chem. Res. 2005, 38, 293. [2] S. Dehnen, M. Melullis, Coord. Chem. Rev. 2007, 251, 1259. [3] F. Lips, R. Clérac, S. Dehnen, J. Am. Chem. Soc. 2011, 133, 14168. [4] S. Haddadpour, M. Melullis, H. Staesche, C.R. Mariappan, B. Roling, R. Clérac, S. Dehnen, Inorg. Chem. 2009, 48, 1689. [5] Z. Hassanzadeh Fard, M. Reza Halvagar, S. Dehnen, J. Am. Chem. Soc. 2010, 32, 2848. [6] F. Lips, M. Hołyńska, R. Clerac, U. Linne, I. Schellenberg, R. Pöttgen, F.Weigend, S. Dehnen, J. Am. Chem. Soc. 2012, 134, 1181. [7] Y. Lin, W. Massa, S. Dehnen, J. Am. Chem Soc. 2012, 134, 4497.

Keynote 3 1

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Novel Ring Systems from Disilynes

Akira Sekiguchi (sekiguch@chem.tsukuba.ac.jp)

Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan

The stable disilyne with a silicon-silicon triple bond bearing two bulky substituents, SiiPr[CH(SiMe3)2]2 groups have been prepared in our group,[1] and we reported a full characterization of the first isolable crystalline disilyne 1, RSi≡SiR (R = SiiPr[CH(SiMe3)2]2), showing that the silicon–silicon triple bond is not linear, but trans-bent, which results in two nondegenerate occupied -MOs and two unoccupied antibonding *-MOs.[2,3] To understand the nature of the -bonding of the silicon–silicon triple bond, we have investigated the reactivity of the disilyne 1 toward a variety of reactants, such as alkenes, alkynes, RLi (R = Me, tBu), alkali metals, nitriles, silyl cyanides, amines, hydroboranes, 1,3,4,5-tetramethylimidazol-2-ylidene, and 4-dimethylaminopyridine, azobenzenes, carbonyl compounds, which has opened a new field of unsaturated heavier Group 14 element chemistry. The reactivity of 1 for the construction of the novel ring systems will be reported.[4]

[1] Sekiguchi, A.; Kinjo, R.; Ichinohe, M. Science, 2004, 305, 1755. [2] Kravchenko, V.; Kinjo, R.; Sekiguchi, A.; Ichinohe, M.; West, R.; Balazs, Y. S.; Schmidt, A.; Karni,

M.; Apeloig, Y. J. Am. Chem. Soc. 2006, 128, 14472. [3] Murata, Y.; Ichinohe, M.; Sekiguchi, A. J. Am. Chem. Soc. 2010, 132, 16768. [4] For the reactivity of 1, see: (a) Kinjo, R.; Ichinohe, M.; Sekiguchi, A.; J. Am. Chem. Soc. 2007, 129,

26. (b) Kinjo, R.; Ichinohe, M.; Sekiguchi, A.; Takagi, N.; Sumimoto, M.; Nagase, S. J. Am. Chem. Soc. 2007, 129, 7766. (c) Takeuchi, K.; Ichinohe, M.; Sekiguchi, A. J. Am. Chem. Soc. 2008, 130, 16848. (d) Yamaguchi, T.; Sekiguchi, A.; Driess, M. J. Am. Chem. Soc. 2010, 132, 14061. (e) Yamaguchi, T.; Sekiguchi, A. J. Am. Chem. Soc. 2011, 133, 7352. (f) Takeuchi, K.; Ichinohe, M.; Sekiguchi, J. Am. Chem. Soc. 2011, 133, 12478. (g) Yamaguchi, T.; Asay, M.; Sekiguchi, A. J. Am. Chem. Soc. 2012, 134, 836.

Plenary 2

IRIS-13 Victoria

18

B1–B2 = 159.2(5) pm

B1–B2 = 144.9(3) pm

Single, Double, Triple, Chains: New Forays into Boron-Boron-Bond Formation

Holger Braunschweig

(holger.braunschweig@uni-wuerzburg.de) Institute of Inorganic Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany,

Due to its inherent electron deficiency, boron prefers non-classical bonding regimes when combined to molecules with itself - in other words, boron forms polyhedral boranes, made up of multicenter bonds, rather than chains or rings with electron-precise boron-boron bonds. In the case of the latter, only very few well-defined examples have been published over the past decades, which all suffer from low-yielding, non-selective syntheses that solely rely on reductive coupling of amino(halo)boranes. Consequently, the area of classical boron-boron multiple bonds is relatively undeveloped. Over the past two years we have put significant effort into the development of new synthetic strategies to overcome this seemingly element-specific deficiency. Here, initial results on the following topics will be presented:

metal-mediated dehydrocoupling of boranes[1]

improved reduction protocols for NHC-stabilized diborenes

and diborynes[2]

metal-promoted catenation of borylenes[3]

[1] Angew. Chem. Int. Ed. 2011, 50, 12613; Eur. Patent EP 11176448.6, 2011, submitted; Chem. Eur. J.

2012, in press. [2] Science, 2012, in press. [3] Nature Chemistry, 2012, in press; Angew. Chem. Int. Ed. 2012, 51, in press.

O

B B

O

O O

catalystO

B

O

H– H2

=Me

Me

MeMe

O

O

O

O

O

O

pincat

,

e.g. 0.05 mol% Pt (20 h); 11600 TON B2pin2

max = 599

N

NiPr

iPr

iPr

iPr

BBNN iPr

iPr

iPriPr

Plenary 3

IRIS-13 Victoria

19

Synthetic Investigations involving Unsaturated Phosphorus Intermediates

Alexandra Velian, Daniel Tofan, Lee-Ping Wang and Christopher C. Cummins (ccummins@mit.edu)

Department of Chemistry, Massachusetts Institute of Technology, USA Ultraviolet irradiation of P4 in the presence of 2,3-dimethylbutadiene (dmb) affords bicyclic organophosphorus ring systems containing a diphosphane P—P bond at the [4.4.0] ring fusion. Multireference CASSCF(4,9)-RSPT3 calculations have been carried out to investigate the P4 excited state potential energy surface; these theoretical studies have uncovered a direct dissociation pathway for conversion of P4 into two P2 molecules, making P2 a plausible intermediate in the observed reaction with 2,3-dimethylbutadiene. New synthetic investigations stemming from the P2 double Diels-Alder adduct with dmb will be described, including single and double oxidation, reactions with sulfur-atom sources, and organic azide reactions. The latter have provided new bis-iminophosphane molecules suited to serve as transition-metal ligands by virtue of pre-organization. Studies of a nickel complex will be presented. In addition, bicyclo[2.2.2] group 10 complexes of the type L2M2P2(dmb)6 (see Figure; M = Ni, Pd, and Pt) will be discussed in terms of their self-assembly and ligand exchange reactions of the axial ligands L, where L = PPh3, AsPh3, SbPh3, CN(2,6-xylyl) etc.

Keynote 4 1

IRIS-13 Victoria

20

The Influence of Donors on the Reactivity of Group 14 (Di)metallenes

Kim M. Baines (kbaines2@uwo.ca)

Department of Chemistry, Western University, London, Ontario, N6A 5B7, Canada One of the most important advances in inorganic chemistry over the last 30 years was the discovery of stable (at rt under an inert atmosphere) multiply bonded species of the heavier main group elements. The spectroscopic and structural characterization of these unsaturated species has profoundly influenced our understanding of structure, bonding and reactivity.[1] Multiply bonded compounds of the heavier main group elements have also proven to be powerful building blocks in organometallic/inorganic synthesis just as alkenes and alkynes are in organic synthesis. An impressive array of previously inaccessible compounds, particularly ring systems, has been made from (di)metallenes(ynes) (referring to metallenes (M=C), dimetallenes (M=M) and dimetallynes (M≡M)).[2] Even more exciting are the innovative applications of this chemistry that are now being explored. Some addition reactions of distannynes (RSn≡SnR) have been found to be reversible suggesting that the use of multiply bonded compounds in catalysis is now in the realm of possibility.[3] Other intriguing examples include the exploitation of the highly regiospecific cycloaddition reactions of silenes (R2Si=CR2) in organic synthesis,[4] the addition polymerization of silenes,[5] germenes (R2Ge=CR2)[6] and phosphaalkenes (RP=CR2)[7] to give novel inorganic materials. To achieve the full potential of unsaturated heavier main group compounds, it is critical to have a broad understanding of their reactivity. Although it has long been recognized that polarized silenes and germenes form complexes with donors, over the past few years, we have noted a few striking examples of how a complexed donor can dramatically influence the reaction pathway of a (di)metallene. In this presentation, the influence of donors on the reactivity of (di)metallenes will be discussed.

[1] For authoritative reviews see: Power et al. Chem. Rev. 2010 110, 3877; Robinson et al. Chem.

Commun. 2009 5201. [2] Numerous reviews have been published: Si: Weidenbruch in “Chem of Organic Si Cmpds” (Eds

Rappoport, Apeloig) Wiley, 3 (2001) 391; Kira J. Organomet. Chem. 2004 689, 4475; Mueller et al. in “Chem of Organic Si Cmpds” (Eds Rappoport, Apeloig) Wiley, 2 (1998) 857. Ge: Tokitoh et al. in “Chem of Organic Ge, Sn and Pb Cmpds” (Eds Rappoport, Apeloig) Wiley, 2 (2002) 843; Weidenbruch, Organomet. 2003 22, 4348 P: Dillon et al. “P: the carbon copy” Wiley 1998.

[3] Power Nature 2010 263, 171. [4] Ottosson et al. Chem. Eur. J. 2006 12, 1576. [5] Baines et al. Chem. Mat. 2008 20, 5948. [6] Baines et al. Chem. Commun. 2008 2346. [7] Gates et al. Dalton Trans. 2010 39, 3151.

Keynote 5 1

IRIS-13 Victoria

21

The Effect of Base-coordination to the Si=Si Double Bonds of Cyclotrisilenes

Michael J. Cowley,a Anukul Jana,a Kinga Leszczyńska,b Kai Abersfelder,a Peter Jutzi,b and David Scheschkewitza

(scheschkewitz@mx.uni-saarland.de) a Krupp-Chair of General and Inorganic Chemistry, Saarland University, D-66125 Saarbrücken,

Germany b Faculty of Chemistry, University of Bielefeld, D-33613 Bielefeld, Germany,

Unsaturated compounds with heavier main group elements have received considerable attention in the last few decades. Recently, low-coordinate main-group compounds have been likened to transition metals because of their vacant coordination site.[1] Such similarities raise the possibility of main group systems filling roles previously taken by transition metal compounds, for example in applications such as homogeneous catalysis. For this reason, main-group compounds displaying typical transition-metal type behaviour are of great interest. We will discuss recent results arising from our investigations into the reactivity of cyclotrisilenes and related germanium-containing compounds with Lewis bases.

For example, N-heterocyclic carbene 2 binds reversibly to cyclotrisilene 1, forming the NHC-cyclotrisilene adduct 3, which constitutes the first example of reversible base coordination to a Si-Si double bond. Compound 3 can be considered an experimental example of the charge separated resonance structures frequently used in bonding models of heavier main group multiple bonds. Furthermore, the reversibility of the NHC coordination of 1 by 2 evokes reversible ligand coordination at transition metal centres, a prerequisite for catalytic activity in such systems. [1] Power, P. P. Nature. 2010, 463, 171-177.

Keynote 6 1

IRIS-13 Victoria

22

Reactions of Small Molecules with Main Group Compounds Under Ambient Conditions

Philip P. Power

(pppower@ucdavis.edu) Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616 USA

The lecture will summarize the work of the author and his group in the title area beginning with their discovery of the reaction of hydrogen with a digermyne in 2005. Recent work involving the addition and insertion reactions of cyclic and acyclic olefins with group 13 and group 14 unsaturated, multiple bonded species and the observation of C-H bond activation will also be a major theme of the presentation.

Plenary 4

IRIS-13 Victoria

23

Boron Containing Heteroacenes

Thomas K. Wood, Lauren G. Mercier, Juan F. Araneda, Benedikt Neue, Warren E. Piers and Masood Parvez

(wpiers@ucalgary.ca) Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4

Canada One way to modify the properties of extended aromatic hydrocarbons is to transpose one or more carbon atoms with other elements in the framework of the organic molecule. We have thus been investigating the chemistry of extended aromatic and antiaromatic systems that utilize boron atoms in place of CH units and observe the changes in properties of the resulting boracycles. Further, exchange of C-C units for isoelectronic B-N units is another approach we have been exploring. In order to do this, new synthetic methods are required; in providing an overview of our recent results in this area, this lecture will emphasize synthetic methodology as well as the unique properties of the boron containing analogs of the all carbon frameworks. Materials using antiaromatic 5 membered boroles and aromatic 6 membered borabenzene or 7 membered borepin rings as building blocks in heteroacenes will be discussed.

Plenary 5

IRIS-13 Victoria

24

C-H∙∙∙∙X Hydrogen Bonding in Carbocation Salts

Christopher A Reed, Evgenii S. Stoyanov, Irina V. Stoyanova and Fook S. Tham (chris.reed@ucr.edu)

Center for s and p Block Chemistry, University of California, Riverside, California 92521, USA The textbook explanation for the stability of t-butyl cation is positive charge delocalization via hyperconjugation. Aligned C-H bonds donate electron density into the formally empty pz orbital. There is no doubt that this is correct for the isolated (gas phase) cation because the gas phase IR spectrum of t-Bu+ shows truly outstanding agreement with that calculated for the Cs symmetry structure.[1] Hyperconjugation was invoked by Olah in 1964 to explain the unusually low IR frequency of the C-H stretch (νmax 2830 cm-1) of t-Bu+ in an SbF5 superacid matrix.[2] Near coincidence with νmax in the gas phase (2834 cm-1) has left the impression that the same explanation solely rationalizes the stability of t-Bu+ in condensed phases. We now show that this convergence of gas and condensed phase spectral data was entirely fortuitous. The C-H stretch in the IR spectrum of t-Bu+ in the solid state varies linearly as a function of anion basicity on the νNH scale3 and requires explanation not only in terms of hyperconjugation but also of H-bonding (Figure). H-bonding also stabilizes benzenium ion (C6H7

+) salts.

[1] G. E. Douberly, A. M. Ricks, B. W. Ticknor, P. v. R. Schleyer, M. A. Duncan, J. Am. Chem. Soc.,

2007, 129, 13782. [2] G. A. Olah, E. B. Baker, J. C. Evans, W. S. Tolgyesi, J. S. McIntyre, Bastien, I. J. J. Am .Chem. Soc.

1964, 86, 1360. [3] E. S. Stoyanov, K.-C. Kim, C. A. Reed, J. Am. Chem. Soc. 2006, 128, 8500.

Keynote 7 1

IRIS-13 Victoria

25

Cationic Polyphosphorus Ring- and Cage-Compounds from P4

Jan J. Weigand,1 Michael H. Holthausen,1 Kai-Oliver Feldmann,1 Gernot Frenking,2 Maximilian Donath1 and Stephen Schulz1

(jweigand@uni-muenster.de) 1Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster,

Corrensstraße 30, 48149 Münster, Germany 2Institut für Anorganische Chemie, Philipps Universität Marburg, Germany

White phosphorus is the most notable allotrope of elemental phosphorus in terms of reactivity and represents the entry point for the synthesis of organophosphorus compounds (OPCs). Substantial efforts have been devoted to the development of direct P4 functionalization to escape the traditional stages via the intermediacy of PCl3 and subsequent transformation reactions. In this respect we are developing general protocols for the formation of cationic phosphorus cages by consecutive insertion of phoshenium cations[1] into P-P bonds of P4 to form monocationic cages of the type [R2P5]+, [RP5Cl]+ and [P5Cl2]+ (R = alky, aryl, NR2) as well as dicationic [R4P6]2+ and tricationic [R6P7]3+ species.[2-5] Recently, we have been able to stepwise breakdown our cationic [RP5Cl]+ (R = Dipp) cages by the nucleophilic reaction with NHCs (N-heterocyclic carbenes, L) into cationic [L2P4]2+, [L2P3]+, and [DippP2]+ fragments which represent novel [P] building blocks.[6]

[1] Weigand, J. J.; Burford, N.; Decken, A.; Schulz, A. Eur. J. Inorg. Chem., 2007, 4868. [2] Weigand, J. J.; Holthausen, M. H.; Fröhlich, R. Angew. Chem. Int. Ed. 2009, 48, 295. [3] Weigand, J. J.; Holthausen, M. H. J. Am. Chem. Soc. 2009, 131, 14210. [4] Holthausen, M. H.; Weigand, J. J. Z. Anorg. Allg. Chem. 2012, DOI: 10.1002/zaac.201200123. [5] Holthausen, M. H.; Feldmann, K.-O.; Schulz, S.; Hepp, A.; Weigand, J. J. Inorg. Chem. 2012, 131,

3374. [6] Holthausen, M. H.; Richter, R.; Hepp, A.; Weigand, J. J Chem. Commun. 2010, 46, 6921.

Keynote 8 1

IRIS-13 Victoria

26

Exploitation of Boryl Substituents for the Stabilization of Novel Sub-valent Main Group Systems

Andrey Protchenko,a Liban Saleh,a Krishna Hassomal Birjkumar,b Nikolas Kaltsoyannis,b Cameron

Jones,c Philip Mountforda and Simon Aldridgea

(Simon.Aldridge@chem.ox.ac.uk) a Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road,

Oxford, OX1 3QR, UK b Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon

Street, London, WC1H 0AJ, UK c School of Chemistry, Monash University, Melbourne, VIC, 3800, Australia

The extremely strong -donor capabilities of the boryl ligand, BX2

-, have been well documented in transition metal chemistry, as a result of extensive studies of structure and reactivity made over the last 20 years. The use of highly sterically demanding variants as spectator ligands in the stabilization of low coordinate species, however, has been facilitated only recently through the synthesis of nucleophilic boryl reagents.[1] As a result of the availability of boryllithium species such as {(HCNDipp)2B}Li(thf)2 (Dipp = 2,6-iPr2C6H3), for example, the introduction of the BX2 function by reaction with metal electrophiles has been opened up as a new synthetic methodology. In recent work we have exploited this approach, together with the strong -donor capabilities and high steric demands of the [(HCNDipp)2B]- ligand in the synthesis of novel Main Group systems featuring unusual coordination numbers and/or oxidation states. The current presentation will focus on such systems from Groups 12-14.[2] As an example, boryl ancillary ligands have been exploited in the synthesis of the first example of a simple two-coordinate acyclic silylene, SiR2, a class of compound which has hitherto been identified only as a transient intermediate or thermally labile species. By making use of the [(HCNDipp)2B] substituent, an isolable monomeric species, Si{B(NDippCH)2}{N(SiMe3)Dipp}, can be synthesized which is stable in the solid state up to 130oC (see Scheme). This silylene species undergoes facile oxidative addition reactions with dihydrogen (at sub-ambient temperatures) and with alkyl C-H bonds, consistent with a low singlet-triplet gap (103.9 kJ mol-1), thus demonstrating fundamental modes of reactivity more characteristic of Transition Metal systems.

[1] Segawa, Y.; Yamashita, M.; Nozaki, K. Science 2006, 314, 113. [2] Protchenko, A.; Birjkumar, K. H.; Dange, D.; Schwarz, A. D.; Vidovic, D.; Jones, C.; Kaltsoyannis,

N.; Mountford, P.; Aldridge, S. submitted.

Keynote 9 1

IRIS-13 Victoria

27

Unusual Chemical Bonds in Cyclic Ditetrylenes

Gernot Frenking (frenking@chemie.uni-marburg.de)

Fachbereich Chemie, Philipps-Universität, Hans-Meerwein-Strasse, D-35043 Marburg, Germany

Very recently, the dimer of a silaisonitrile (1) which possesses two divalent silicon atoms in a four-membered ring could become isolated and structurally characterized.[1] Compound 1 which is the first example of a base-free disilylene has two amido groups in 1,3-position bonded to the silicon atoms. Another four-membered compound with two divalent group14 atoms is the digermylene 2 where the germanium atoms are bonded to gallium. Compound 2 has also been synthesized and its geometry could become determined by x-ray crystallography.[2] The lecture focuses on the unusual bonding situation in 1 and 2 and their group-14 homologues.

1 2

[1] R. S. Ghadwal, H. W. Roesky, K. Pröpper, B. Dittrich, S. Klein, G. Frenking, Angew. Chem. Int. Ed.

2011, 50, 5374–5378. [2] A. Doddi, C. Gemel, K. Freitag, M. Winter, R. A Fischer,C. Goedecke, H. S. Rzepa, G. Frenking,

Angew. Chem. Int. Ed., submitted for publ.

Keynote 10 1

IRIS-13 Victoria

28

P

ONa

Phosphorus-rich Inorganic Ring Systems

Evamarie Hey-Hawkins,a Santiago Gómez-Ruiz,a,b Aslihan Kircali,a Ivana Jevtovicha and Peter Lönneckea

(hey@uni-leipzig.de) aInstitut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany, bDepartamento de Química Inorgánica y Analítica, E.S.C.E.T. Universidad Rey Juan Carlos, Calle

Tulipán sn, 28933, Móstoles, Spain

The chemistry of polyphosphorus compounds has developed impressively over the last four decades. Thus, a great number of cyclic and catenated polyphosphanes (both as hydrides and as organic derivatives) have been synthesised and successfully characterised.[1] The chemistry of these compounds can be analogous to that of related carbon compounds.[2] On the other hand, the chemistry of cyclic and catenated oligophosphanide anions has hardly been explored until recently, as selective and facile syntheses were mostly unknown. We have developed a simple synthetic route to the alkali metal salts M2(P4R4) (M = Na, K; R = Ph, tBu, Mes) and cyclo-(P5

tBu4)– anion,[3] which display unusual reactivity and intriguing chemistry.[4]

Thus, MCl2 (M = Sn, Pb) and BiCl3 react with cyclo-(P5

tBu4)– to form the novel dimers {cyclo-(P5tBu4)}2

and {cyclo-(P4tBu3)PtBu2}2, as well as the secondary phosphine cyclo-(P5

tBu4H). Furthermore, a wide range of transition metal complexes (e.g., Zr, Ta, Cr, Mo, W, Mn, Fe, Rh, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd) with linear and cyclic oligophosphanide ligands is known. Besides the academic challenge, metal complexes with anionic polyphosphorus ligands are of interest as potential precursors for the development of rational syntheses of binary metal phosphides (MxPy), which are a fascinating class of compounds with unusual structures and interesting properties for materials science.[5] Financial support from the Deutsche Forschungsgemeinschaft (He 1376/22-3 and within the Graduate School of Excellence BuildMoNa) and the EU-COST Action CM0802 PhoSciNet is gratefully acknowledged.

[1] See for example: M. Baudler, K. Glinka, Chem. Rev. 1993, 93,1623-1667. [2] K.B. Dillon, F. Mathey, J.F. Nixon, Phosphorus the Carbon Copy: From Organophosphorus to

Phospha-organic Chemistry. Wiley, Chichester, 1998. [3] A. Schisler, U. Huniar, P. Lönnecke, R. Ahlrichs, E. Hey-Hawkins, Angew. Chem. Int. Ed. 2001, 40,

4217-4219. [4] S. Gómez-Ruiz, E. Hey-Hawkins, in: Phosphorus Chemistry: Catalysis and Material Science

Applications, ed. M. Peruzzini, L. Gonsalvi, Springer, Volume 37, 2011, 85-120; S. Gómez-Ruiz, E. Hey-Hawkins, New J. Chem. 2010, 34, 1525-1532; S. Gómez-Ruiz, E. Hey-Hawkins, in: Recent Trends in Main Group Chemistry, ed. T. Chivers, Coord. Chem. Rev. 2011, 255, 1360-1386; A. Kircali, R. Frank, S. Gómez-Ruiz, B. Kirchner, E. Hey-Hawkins, ChemPlusChem 2012 (in press, DOI: 10.1002/cplu.201200013).

[5] H.-G. von Schnering, W. Hönle, Chem. Rev. 1988, 88, 243-273.

Na(THF)3{cyclo-(P5tBu4)} {cyclo-(P5

tBu4)}2 Manganese(I) complex Au4P20 framework of [Au4{PtBu(P4

tBu3)}4]

Plenary 6

IRIS-13 Victoria

29

Accessing the Inaccessible: Molecular Magnesium(I) Compounds as Specialist Reducing Agents for the Synthetic Chemist

Cameron Jones

(cameron.jones@monash.edu) School of Chemistry, Monash University, Melbourne, VIC, 3800, Australia

The chemistry of compounds containing p-block elements in very low oxidation states has rapidly advanced over the last two decades. More than being just chemical curiosities, these species have begun to find a variety of applications in synthesis, small molecule activations etc.[1] In 2007, we extended this field to the s-block with the preparation of the first room temperature stable molecular compounds containing magnesium-magnesium covalent bonds, viz. LMgMgL (L = bulky guanidinate or -diketiminate 1).[2] Subsequently, we have found such magnesium(I) compounds to have considerable utility as soluble, selective, stoichiometric reducing agents in organic and inorganic synthesis. In many cases, the products obtained from reactions involving these compounds are not accessible using traditional reducing agents, e.g. alkali metals or SmI2. This is especially so for reductions of p-block element precursors, which have yielded a variety of unprecedented low oxidation state group 13 and 14 complex types, e.g. 2-5.[3] Examples of these compounds, e.g. 5, are emerging as powerful reagents for the facile, "transition metal-like" activation of H2, CO2, NH3 etc. In this lecture, our recent efforts to develop the chemistry of magnesium(I) dimers and very low oxidation state p-block compounds will be presented.

[1] (a) P.P. Power, Nature, 2010, 463, 171; (b) M. Asay, C. Jones, M. Driess, Chem. Rev., 2011, 111, 354.

[2] S.P. Green, C. Jones, A. Stasch, Science, 2007, 305, 1136. [3] (a) J. Li, C. Schenk, C. Goedecke, G. Frenking, C. Jones, J. Am. Chem. Soc., 2011, 133, 18622; (b)

W.D. Woodul, E. Carter, R. Müller, A.F. Richards, A. Stasch, M. Kaupp, D.M. Murphy, M. Driess, C. Jones, J. Am. Chem. Soc., 2011, 133, 10074; (c) S.J. Bonhady, D. Collis, G. Frenking, N. Holzmann, C. Jones, A. Stasch, Nature Chem., 2010, 2, 865.

Plenary 7

IRIS-13 Victoria

30

Simple Ligands, Not so Simple Chemistry!

Paul J. Ragogna and Allison L. Brazeau (pragogna@uwo.ca)

Department of Chemistry and the Center for Advanced Materials and Biomaterials Research Western University, 1151 Richmond St, London, Ontario, N6A 5B7, Canada

Over the last several years, work in our group has centered on developing new structure and bonding motifs for the main group elements, specifically for elements in group 15 and 16. To push forward in this area, we have adapted simple ligand sets used widely within the d-block, for use in our chemistry. Two such examples are the pyridyl tethered 1,2-bis(imino)acenaphthene (1) (a.k.a. “clamshell”) and the dianionic guanidinate ligands (2). Both display rather predictable chemistry for the transition metals, but not so for the group 15 elements (P, As, Sb). Specific examples for each ligand set will be presented, where most interesting is the reluctance of the P-X bond (X = Cl, Br) within the 4-membered diguanidainate rings to undergo halide abstraction.

N N

N

NN

N

R R

R

1 2 [1] D. H. Leung, J. W. Ziller and Z. Guan, J. Am. Chem. Soc., 2008, 130, 7538–7539. [2] A. L. Brazeau, M. Hänninen, H. Tuononen, N. D. Jones, P. J. Ragogna J. Am. Chem. Soc. 2012, 134, 5398-5414. [3] A. L. Brazeau, N. D. Jones, P. J. Ragogna Dalton. Trans. 2012 41 7890-7896. [4] A. L. Brazeau, A. S. Nikouline, P. J. Ragogna Chem. Commun. 2011, 47, 4817-4819. [5] A. L. Brazeau, C. A. Caputo, C. D. Martin, N. D. Jones and P. J. Ragogna Dalton Trans. 2010, 39, 11069-11073.

Keynote 11 1

IRIS-13 Victoria

31

Lewis Acidic Properties of Heavy Group 15 and 16 Compounds

Casey Wade, Tzu-Pin Lin, Iou-Sheng Ke, James Jones and François P. Gabbaï (francois@tamu.edu)

Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843-3255, USA As part of our ongoing investigations in the chemistry of main group Lewis acids, we have recently become interested in the properties of heavy pnictogenium[1] and chalcogenium ions.[2] Owing to the electropositive character of the central atom as well as to the presence of low lying vacant orbitals, these onium ions behave as unusual Lewis acids. In this presentation, we will illustrate some of these characteristics by describing how derivatives containing stibonium or telluronium ions can be used for the selective complexation of fluoride ions in protic solvents. We will also show that heavy pnictogen can behave as Z-ligands and engage electron rich transition metals in unusual donor acceptor interactions.[3]

Sb

FB

Left: Fluoride anion complexation by a bidentate stibonium borane. Right: Synthesis of a gold-antimony derivative featuring a Au→Sb bond.

[1] a) C. R. Wade, F. P. Gabbaï, Organometallics 2011, 30, 4479-4481; b) C. R. Wade, I.-S. Ke, F. P.

Gabbaï, Angew. Chem. 2012, 124, 493-496; Angew. Chem. Int. Ed. 2012, 51, 478-481. [2] H. Zhao, F. P. Gabbaï, Nat. Chem. 2010, 2, 984-990. [3] a) C. R. Wade, F. P. Gabbaï, Angew. Chem., 2011, 123, 7507-7510; Angew. Chem. Int. Ed. 2011, 50,

7369-7372; b) C. R. Wade, T.-P. Lin, R. C. Nelson, E. A. Mader, J. T. Miller, F. P. Gabbaï, J. Am. Chem. Soc. 2011, 133, 8948-8955; c) T.-P. Lin, C. R. Wade, L. M. Pérez, F. P. Gabbaï, Angew. Chem., 2010, 122, 6501-6504; Angew. Chem. Int. Ed. 2010, 49, 6357-6360; d) T.-P. Lin, R. C. Nelson, T. Wu, J. T. Miller, F. P. Gabbai, Chem. Sci. 2012, 3, 1128-1136; e) T.-P. Lin, I.-S. Ke, F. P. Gabbaï, Angew. Chem. Int. Ed. 2012, early view.

Keynote 12 1

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Catalytic and Stoichiometric Bond-Forming Reactions Using Main Group Metals

Dominic S. Wright

(dsw1000@cam.ac.uk) Chemistry Department, Cambridge University, Lensfield Rd., Cambridge CB2 1EW UK

The dehydrocoupling of element-H bonds (equ. 1) has been dominated by transition metal reagents and catalysts. However, it is becoming clear that high reactivity and catalytic activity can also be obtained in this type of reaction using main group metal-based systems (even in the absence accessible d-orbitals in the valence shell). Redox-active main group bases like M(NMe2)n (M = can be highly effective in the stoichiometric dehydrocoupling of P-P and even N-N bonds, with some unusual reactivity being observed.[1,2] Surprisingly, even simple Sn(IV) organometallics like Cp*2SnCl2 can function as catalysts in the formation of P-P bonds and are directly analogous in their behaviour to transition metal systems based on Zr(IV).[3] This behaviour can also be extended to other dehydrocoupling reactions. Al(III) amides have been shown to be as active as a number of precious metal catalysts in the dehydrocoupling of B-N bonds, and exhibit closely related reaction characteristics.[4,5] Where more redox-active group 13 metals are employed unique chemistry can be observed (which is not seen for transition metals). A case in point is the reaction of Ga{N(SiMe3)2}3 with NH3BH3 which gives the unusual product 1 (below), in which a combination of B-N coupling and N(SiMe3)2 ligand rearrangement has occurred.[5,6]

[1] R. J. Less, R. Melen, V. Naseri, D. S. Wright, Chem. Commun., 2009, 4929. [2] R. J. Less, .V. Naseri, M. McPartlin, D. S. Wright, Chem. Commun. 2011, 47, 6129. [3] V. Naseri, R. J. Less, M. McPartlin, R. E. Mulvey, D. S. Wright, J. Chem. Soc., Chem. Commun.,

2010, 46, 5000. [4] H. Cowley, R. L. Melen, J. M. Rawson, D. S. Wright, Chem Commun., 2011, 47, 2682. [5] M. M. Hansmann, R. L. Melen, D S. Wright, Chem. Sci., 2011, 2, 1554. [6] see also, R. J. Less, R. L. Melen, D. S. Wright, RSC Adv., 2012, review, in press.

1

Keynote 13 1

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Challenges in Metal Oxo Cluster Chemistry for Energy-Saving Materials and Catalysis

Yilmaz Aksu, Kerim Samedov, Johannes Pfrommer and Matthias Driess

(matthias.driess@tu-berlin.de) Technische Universität Berlin, Institute of Chemistry: Metalorganics and Inorganic Materials, Strasse

des 17. Juni 135, Sekr. C2, 10623 Berlin, Germany

Current research activities in materials chemistry are devoted to the development of innovative and abundant materials suitable for conversion and storage of solar energy into chemicals (artificial photosynthesis). At the same time, there is an enormous demand for innovative new materials for energy-saving in electronic devices. Transparent conducting oxides (TCOs) are key components in organic light emitting diodes (OLED’s) for solar cells, photocatalysts, transparent electrodes in displays and Field Effect Transistors (FET). Unfortunately, transparent electrodes in flat-panel technology, photovoltaics or FETs rely on expensive indium tin oxide (ITO; In2O3:Sn doped with 5% Sn) which generate a bottleneck for the growing demand, combined with the relatively low abundance of indium. Changing the chemistry and using alternative materials systems based on abundant metal oxides provides a solution: Applying the concept of molecular metalorganic single-source precursors opened new doorways to innovative new TCO materials for various applications, including bioelectrocatalysis (Fig. 1).[1-6] In my talk the synthesis of new main group metal-oxo cluster precursors for reliable access to inexpensive and urgently needed multi-metal oxides for energy-saving and photocatalysis (artificial photosynthesis) will be discussed.

Fig. 1. From a molecular In(I)-Sn(II) oxo cage to a bioelectrocatalytic device.[5]

[1] Y. Aksu, M. Driess, Angew. Chem. Int. Ed. 2009, 48, 7778. [2] Y. Aksu, T. Lüthge, R. Fügemann, M. Inhester, M. Driess, „Transparent electrical conducting layers:

Procedure to prepare the layers and their applications”, Patent Appl. 2006E00310DE (Germany) and 102007013181.1 (China, USA)

[3] Y. Aksu, S. Jana, M. Driess, Dalton Trans. 2009, 1516. [4] M. Tsaroucha, Y. Aksu, E. Irran, M. Driess, Chem. Mater. 2011, 23, 2428–2438. [5] Y. Aksu, S. Frasca, U. Wollenberger, M. Driess, A. Thomas, Chem. Mater. 2011, 23, 1798–1804. [6] K. Samedov, Y. Aksu, M. Driess, Chem. Eur. J. 2012, accepted. Acknowledgment: We thank the Cluster of Excellence “UniCat”, financed by the DFG and administered

by the TU Berlin, and the BMBF (L2H) for financial support.

Plenary 8

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34

Acids of the Heavier p-Block Elements and Related Metalloxanes

Jens Beckmann (j.beckmann@uni-bremen.de)

Institute of Inorganic and Physical Chemistry, Bremen University, Bremen, Germany Exploratory chemistry is presented of the novel p-block element acids 1-5,[1-4] which can be regarded as heavier congeners of sulfinic acids, sulfonic acids, phosphonic acids, carboxylic acids and boronic acids, respectively. In 1-5, kinetic stabilization was achieved using a bulky m-terphenyl substituent that prevents extensive aggregation. Attempts at obtaining similar acids by the electronic stabilization using an intramolecularly coordinating peri-N donor substituent were less effective and provided (partially) condensed polynuclear products, as exemplified by 6 and 7.[5] Reactions of 1-7 and related compounds gave rise to new inorganic heterocycles, such as 8-10.[6-8]

[1] J. Beckmann, P. Finke, M. Hesse, B. Wettig Angew. Chem. Int. Ed. 2008, 47, 9982. [2] J. Beckmann, J. Bolsinger, M. Hesse, P. Finke Angew. Chem. Int. Ed. 2010, 49, 8030. [3] S. U. Ahmad, J. Beckmann, A. Duthie Chem. Asian J. 2010, 5, 160. [4] S. U. Ahmad, J. Beckmann Organometallics 2009, 28, 6893. [5] J. Beckmann, J. Bolsinger, A. Duthie Chem. Eur. J. 2011, 17, 930. [6] S. U. Ahmad, J. Beckmann, A. Duthie Organometallics 2012, 31, 3802. [7] J. Beckmann, J. Bolsinger, M. Hesse Organometallics 2009, 28, 4225. [8] J. Beckmann, M. Hesse Organometallics 2009, 28, 2345.

Oral 1

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Cyclometalation and Organometallic Intramolecular-coordination Five-membered Ring Compounds as Universal Reagents

I. Omae

(um5i-oome@asahi-net.or.jp) Omae Research Laboratories, 335-23, Mizuno, Sayama, Saitama, 350 -1317, Japan

Cyclometalation is a type of reactions capable of synthesizing organometallic intramolecular-coordination compounds. By the reactions, five-membered ring compounds are mostly produced. These products are mainly prepared by utilizing transition metal compounds. The first article on the transition metal compounds was reported in 1963 in that π-N=N electrons in azobenzene are donated to a nickel atom to form an intramolecular bond with UV and NMR spectra data. However, in 1965, it was reported that the intramolecular bond was the result of donation of nitrogen lone pair electrons in the azobenzene to a palladium or platinum metal with the UV and NMR spectra data. As the verification of the intramolecular coordination bond to these two contradictive reports, in 1989, it was reported that the intramolecular coordination was shown as the result of coordination of the nitrogen lone pair electrons to the metal atom, which is verified by IR, NMR spectra and X-ray diffraction data on two azobenzene chelate complexes. However, in 1966, before this verification, we already reported the clean verification on the intramolecular bond in organotin compounds as main group metal compounds in Japanese article[1] as follows:

BrCHCOH

O

CH2COH

O

+ Sn Br2Sn CHCOH

O

CH2OC

OH 2

C=O : 1740 cm-1

C=O : 1740 cm-1

C=O : 1710 cm-1

(shift = 30 cm-1)

(shift = 80 cm-1)

2

C=O : 1660 cm-1

cat.

Massive organometallic intramolecular-coordination five-membered ring compounds have been synthesized with not only N and O atoms but also P, As and S atoms as the coordinating atom, and furthermore with coordinating groups such as C=C, C=C-C, Cp, diolefins, etc. The reports on the organometallic intramolecular-coordination compounds having these ligand atoms and ligand groups have been published as many reviews[2,3] since 1971, and a monograph for them was published from Elsevier company in 1986[4]. Especially, the organometallic intramolecular-coordination five-membered ring compounds are surprisingly easily and regioselectively synthesized by using many kinds of metal compounds and with many kinds of substrates. Hence, these reactions are applied as the synthesis of the final products and the intermediates, the products are used as catalysts for chiral reactions, metathesis reactions, cross-coupling reactions, etc., for the production of pharmaceuticals, fine chemicals, etc.[5] Hence, the number of the published research articles is more than 7 times than each of those related to the recent Nobel Prize in synthetic chemistry such as chiral catalysts (2001), metathesis (2005) and cross-coupling reactions (2010) from the Chemical Abstract Database SciFinder Scholar 2012, 1, 26 data. [1] S. Matsuda, S. Kikkawa, I. Omae, Kogyo Kagaku Kyokaishi, 1966, 69, 646. [2] I. Omae, Rev. Silicon, Germanium, Tin and Lead Compounds, 1971, 1, 59. [3] I. Omae, Chem. Rev. , 1979, 79, 287. [4] I. Omae, Organometallic Intramoledular-coordination Compounds, Elsevier, Amsterdam, 1986. [5] I. Omae, Coord. Chem. Rev. 2004, 248, 995; J. Organomet. Chem. 2007, 692, 2608.

Oral 2

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36

Activation and Transformation of Phosphorus-Rich Rings and Cages

M. Scheer, F. Dielmann, S. Welsch, C. Heindl, S. Heinl, C. Schwarzmaier (manfred.scheer@chemie.uni-regensburg.de)

Institute of Inorganic Chemistry, University of Regensburg, Germany

Polyphosphorus species and moieties play an important role in contemporary main group and transition metal chemistry. The talk will focus on two related areas of research: (i) the development of novel starting materials for E4 transfer reactions (E = P, As) and to acquire novel synthetic concepts of activation of white P4 and yellow As4. (ii) the use of substituent-free polyphosphorus ligand complexes in an alternative supramolecular approach. The first topic deals with the synthesis of novel Ag and Zr complexes containing activated Pn and Asn units (n 4). These compounds can be used as unique reagents to transfer En moieties to transition metals under very mild conditions. Moreover, a novel concept for the aggregation of tetrahedral E4 by transition metal compounds is presented resulting in neutral En-rich complexes.[1] In the second part the chemistry of the cyclo-P5 containing complex [Cp*Fe(η5-P5)] is discussed. On one hand it can be transferred by redox-reactions into ionic P-rich complexes. On the other hand it shows unique supramolecular properties since under special conditions it forms together with Cu(I) halides soluble spherical aggregates and supramolecules.[2] By using carboranes or fivefold-symmetric organometallics as a third component soluble giant spheres revealing fullerene-like topology are formed as a consequence of template controlled reactions.[3] The approach to an organometallic nano-sized capsule consisting of cyclo-P5 units and Cu(I) ions is further presented.[4]

[1] F. Dielmann, M. Sierka, A. V. Virovets, M. Scheer, Angew. Chem. 2010, 122, 7012–7016; Angew. Chem. Int. Ed. 2010, 49, 6860–6864. [2] M. Scheer, Dalton Trans. 2008, 4372–4386. [3] A. Schindler, C. Heindl, G. Balázs, C. Gröger, A. V. Virovets, E. V. Peresypkina, M. Scheer, Chem. Eur. J. 2012, 18, 829–835. [4] S. Welsch, C. Gröger, M. Sierka, M. Scheer, Angew. Chem. 2011, 123, 1471–1474; Angew. Chem. Int. Ed. 2011, 50, 1435–1438.

Oral 3

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37

Synthesis and Characterization of Heterocyclic Silicon Based Push-Pull Systems

Uwe Walter Gross and Harald Stueger

(uwe.gross@tugraz.at) Institute of Inorganic Chemistry, Graz University of Technology, Austria

Donor-acceptor (D-A) interactions within various types of D-spacer-A compounds are currently studied extensively in order to address key issues like electron transfer processes, artificial photosynthesis or molecular devices.[1] In this context silicon based oligo- and polysilanes display attractive electronic properties which result from delocalized σ-electrons along the silicon backbone (σ-delocalization).[2] σ-delocalization is particularly pronounced in cyclic Si-Si- bonded systems. Cyclopolysilane rings and cages, therefore, are likely to serve as effective -conjugated bridges in bichromophoric covalently linked donor-bridge-acceptor compounds. In this work we present synthetic routes to novel cyclohexasilanes, which contain endocyclic donor atoms and acceptor substituents in para positions.

Figure 1: Synthetic pathway leading to functionalized heterocyclopolysilanes Photophysical and electrochemical properties of the heterocyclic compounds 5 will be investigated in detail in order to shed light on the extent of intramolecular donor/acceptor interactions via the Si-Si skeleton. [1] Y. Shirota, H. Kageyama, Chem. Rev. 2007, 107, 953-1010. [2] R. West, Pure Appl. Chem. 1982, 54, 1041-1050.

Oral 4

IRIS-13 Victoria

38

Reactions of Cyclodimethylsiloxanes (Me2SiO)n with Silver Salts and Rationalization for Weaker Lewis Basicity of Siloxanes Compared to Ethers

T. Stanley Cameron,a Andreas Decken,b Ingo Krossing,c Jack Passmore,b J. Mikko Rautiainen,d Xinping

Wang,e Xiaoqing Zeng f (juha.rautiainen@oulu.fi)

a Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, B3H 4J3, Canada b Department of Chemistry, University of New Brunswick, Fredericton, NB E3B 5A3, Canada

c Institute for Inorganic and Analytical Chemistry, Albert–Ludwigs–Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany

d Department of Chemistry, P. O. Box 3000, 90014 University of Oulu, Finland e State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, P.R.China

f Division C – Inorganic Chemistry, University of Wuppertal, Gaußstr. 20, 42119 Wuppertal, Germany Reactions of cyclodimethylsiloxanes (Me2SiO)m (m = 3-6) with Ag[SbF6] in SO2(l) have been shown to give equilibrium mixtures of mainly AgDn[SbF6] (n = 6-8) complexes and afford the isolation of [AgD7][SbF6] salt.[1] In contrast reactions of D6 with Ag[Al(ORF)4] and Ag[AlF(ORF)3] in SO2(l) give the corresponding AgD6

+ complex salts. This suggests alternative routes to metal cyclodimethylsiloxane complex salts either via ring transformation reactions or directly from components. The energetics of metal cyclodimethylsiloxane complex formation and relative stabilities of different complexes will be discussed in the presentation. The differences of bonding between siloxanes and ethers and reasons for the lower basicity of siloxanes will be elucidated on the basis of the observed structures and theoretical calculations. Our results show that the inherently weaker binding of siloxanes towards metal cations compared to analogous ethers is mainly due to the high polarity of the silicon oxygen bond that causes high positive atomic charges on silicon atoms and repulsion between silicon atoms and metal ions. This repulsion outweighs the stronger binding between metal ions and the more negatively charged oxygen atoms in siloxanes.

[1] Decken, A., LeBlanc, F. A., Passmore, J., Wang, X., Eur. J. Inorg. Chem. 2006, 4033.

Figure 2 [AgD6]+

Oral 5

IRIS-13 Victoria

39

Novel Four- and Five-membered Binary Pnictogen-Nitrogen-Rings: From Neutral Biradicals to cyclo-Dipnicta-Diazenium Ions

Axel Schulza,b

(axel.schulz@uni-rostock.de) a Institut für Chemie, University of Rostock, b Leibniz-Institut für Katalyse e.V., A.-Einstein-Str. 3A 18059

Rostock, Germany

Four-membered rings of the type [XE(-NR)]2 (Scheme 1, species B), containing alternating pnictogen(III) and nitrogen centers, are called cyclo-1,3-dipnicta(III)-2,4-diazanes (X = halogen, R = bulky substituent).[1,2] This talk deals with the syntheses and full characterization of the whole series of salts bearing the cyclo-dipnicta-diazenium ions (Scheme 1, species C for E = P, As, Sb, and Bi).[3] A new facile synthetic approach is presented for the preparation of the Bi- and Sb-species B by transmetallation reaction starting from [Sn( -NTer)]2.[4] Access to the hitherto unknown biradicaloid species D (E = P,[5] and As[3c]) is easily obtained by reduction with Cp2Ti(btmsa) (btmsa = bistrimethylsilylacetylene). Finally, besides tetrazaphosphols and -arsols, the tetraazastibol (species F) is presented, which could be isolated in an unusual isomerization process starting from cyclo-1,3-distiba(III)-2,4-diazane B and a strong Lewis acid such as B(C6F5)3.[6] Moreover, for the As analogue it was possible to isolate und fully characterize the R–N≡As+ species E bearing a triple bond, and to react E with Me3SiN3 to tetrazaarsole F.[3c,7]

[1] M. S. Balakrishna, D. J. Eisler, T. Chivers, Chem. Soc. Rev. 2007, 36, 650. [2] L. Stahl, Coord. Chem. Rev. 2000, 210, 203.

a) D. Michalik, A. Schulz, A. Villinger, N. Weding, Angew. Chem., Int. Ed. 2008, 47, 6465; b) A. Schulz, A. Villinger, Inorg. Chem. 2009, 48, 7359; c) submitted 2012.

[3] W. A. Merrill, R. J. Wright, C. S. Stanciu, M. M. Olmstead, J. C. Fettinger, P. P. Power, Inorg. Chem. 2010, 49, 7097.

[4] T. Beweries, R. Kuzora, U. Rosenthal, A. Schulz, A. Villinger, Angew. Chem. Int. Ed. 2011, 50, 8974.

[5] M. Lehmann, A. Schulz, A. Villinger, Angew. Chem., Int. Ed. 2011, 50, 5221. [6] A. Schulz, A. Villinger, Angew. Chem., Int. Ed. 2008, 47, 603.

N

NE

N

N

R LAN

E N

EX

X

R

R

N EXR

1/2

-Me3SiX

N ER

LA-X

LA

+Me3SiN3

+Me3SiN3+LA-Me3SiX

N

E N

E

X

R

R

1/2 LA-X

N

E N

ER

R

1/2

AB

C

D

E

F

LA = Lewis acidX = halogenR = bulky substituent

+LA

+2e-

-2X-

Oral 6

IRIS-13 Victoria

40

Thiazyl and Selenazyl Heterocycles as Paramagnetic Ligands

Kathryn E. Preuss (kpreuss@uoguelph.ca)

Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada Our aim is to exploit the properties of well-known thiazyl and selenazyl radicals for use in the design of paramagnetic ligands. By arranging these main-group structures into familiar ligand architectures, we endeavor to contribute a variety of novel, paramagnetic ligands and coordination complexes with unusual and potentially useful properties.[1] Specifically, we will present ligands that incorporate 1,2,3,5-dithiadiazolyl (DTDA) and 1,2,5-dithiazolyl (DTA) heterocycles, and their selenazyl analogs. Coordination complexes of these with 3d transition metal dications (M2+) and lanthanide metal trications (Ln3+) will be discussed. Examples that will be highlighted include a DTDA complex of Mn2+ that forms high spin pairs in the solid state,[2] dimers of DTDA Dy3+ complexes that act as single-molecule magnets (SMM)s, and Gd3+ polymers of a DTA ligand.

[1] Wu, J.; MacDonald, D. J.; Clérac, R.; Jeon, I.-R.; Jennings, M.; Lough, A. J.; Britten, J.; Robertson,

C.; Dube, P. A.; Preuss, K. E.* Inorg. Chem. 2012, 51, 3827-3839. [2] Fatila, E. M.; Goodreid, J.; Clérac, R.; Jennings, M.; Assoud, J.; Preuss, K. E.* Chem. Commun. 2010,

46, 6569.

Oral 7

IRIS-13 Victoria

41

Recent Advances in the Chemistry of N-Heterocyclic Diphosphines

Dietrich Gudat, Daniela Förster, Oliver Puntigam, Jan Nickolaus and Martin Nieger (gudat@iac.uni-stuttgart.de)

Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70550 Stuttgart, Germany Tetraamino-substituted diphosphines featuring both acyclic (I) and cyclic (II) diphosphanyl units are well known to undergo homolytic P–P-bond cleavage to give long-lived phosphanyl radicals:[1,2]

NR

P

RN

PNR

RN

IINR

P

RN

PNR

RN

III

(R'RN)2P P(NRR')2 2 (RR'N)2P

NR

P

RN

2

I

Starting from an improved synthesis which gives access to both bis-diazaphospholenyls II and the ap-propriate CC-saturated bis-diazaphospholidines III we present recent results on the structural and spec-troscopic characterization of these species, including the determination of 1JP,P coupling constants in symmetrical derivatives II, III where the two phosphorus atoms exhibit apparently total magnetic equivalence. Monitoring the equilibrium between bis-diazaphospholenyl IIc (R = 2,6-iPr2C6H3) and the corresponding radical by NMR and EPR spectroscopy allowed further to gather mechanistic information on the diphosphine dissociation, and to obtain experimental data which allow to assess the energetics of the homolytic P–P bond cleavage process. Comparison of the experimental data with the results of thermochemical calculations suggests the importance of including correlation and dispersion effects in the computational model. The ability to access N-heterocyclic diphosphines II, III on a preparative scale stimulated further studies of their chemical properties. As the first results of these investigations, we will report on the addition of II, III to multiple bonds, and the characterization of pseudo-homoleptic phosphenium-metal(0)halides [(NHP)2MCl]2 (NHP = N-heterocyclic phosphenium; M = Pd, Pt). The metal atoms in these specimen are not supported by additional donor ligands but feature according to computational studies direct bonding interaction between centers with a formal d10 electron count. [1] Gynane, M. J. S.; Hudson, A.; Lappert, M. F.; Power, P. P.; Goldwhite, H. Chem. Commun. 1976,

623; Gynane, M. J. S.; Hudson, A.; Lappert, M. F.; Power, P. P.;Goldwhite, H. Dalton Trans. 1980, 2428; Bezombes, J.-P.; Hitchcock, P. B.; Lappert, M. F.; Nycz, J. E., Dalton Trans. 2004, 499; Bezombes, J.-P.; Borisenko, K. B.; Hitchcock, P. B.; Lappert, M. F.; Nycz, J. E.; Rankin, D. W. H.; Robertson, H. E., Dalton Trans. 2004, 1980.

[2] Edge, R.; Less, R. J.; McInnes, E. J. L.; Müther, K.; Naseri, V.; Rawson, J. R.; Wright, D. S., Chem. Commun. 2009, 1691.

Oral 8

IRIS-13 Victoria

42

Boroles going Radical: An Isolable Radical Anion

Johannes Wahler and Holger Braunschweig (johannes.wahler@uni-wuerzburg.de)

Institute of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074 Würzburg, Germany

The concepts of aromaticity and antiaromaticity have evolved into some of the fundamental principles of chemistry. Today, numerous experimental and theoretical techniques are available to substantiate the effect of aromatic stabilization and antiaromatic destabilization. Isolation of antiaromatic compounds, however, still remains challenging as a consequence of their highly reactive nature. The synthesis of free, non-annulated boroles, first reported by J. J. Eisch in 1969, showed that inclusion of a sp2 hybridized BR fragment into a planar conjugated carbacyle is a suitable strategy to approach this purpose.[1] Subsequent experiments and computational results verified not only the antiaromatic character of boroles (four -electrons) but also the aromatic character of borole dianions (six -electrons) generated by chemical reduction of the system.[2,3]

In recent studies we showed that reduction of boroles proceeds stepwise involving an intermediate borole radical anion (five -electrons) which could so far only be characterized by spectroscopic methods from in situ generated substance.[4] Synthesis of 1-mesityl-2,3,4,5-tetraphenylborole (1) allowed us to prepare a stable borole radical anion (2), which we have characterized by means of computational methods, EPR spectroscopy, X-ray crystallography, UV-Vis spectroscopy and a first reactivity assay. Our results indicate the presence of a boron-centered radical with pronounced spin delocalization within the borole annulus rather than to the exo-cyclic aryl groups.[5]

[1] J. J. Eisch, N. K. Hota, S. Kozima, J. Am. Chem. Soc. 1969, 91, 45754577. [2] H. Braunschweig, I. Fernández, G. Frenking, T. Kupfer, Angew. Chem. Int. Ed. 2008, 47, 19511954. [3] J. J. Eisch, J. E. Galle, S. Kozima, J. Am. Chem. Soc. 1986, 108, 379385. [4] H. Braunschweig, F. Breher, C.-W. Chiu, D. Gamon, D. Nied, K. Radacki, Angew. Chem. Int Ed.

2010, 49, 89758978. [5] H. Braunschweig, V. Dyakonov, J. O. C. Jimenez-Halla, K. Kraft, I. Krummenacher, K. Radacki, A.

Sperlich, J. Wahler, Angew. Chem. Int. Ed. 2012, 51, 29772980.

Oral 9

IRIS-13 Victoria

43

Polychalcogen Macrocycles Supported by P2N2 Rings

Andreas Nordheider,a,c Tristram Chivers,a Ramalingam Thirumoorthi,a Ignacio Vargas-Bacab and J. Derek Woollinsc

(chivers@ucalgary.ca)

aDepartment of Chemistry, University of Calgary, Calgary, AB, T2N 1N4, Canada bDepartment of Chemistry and Chemical Biology, McMaster University, 1280 Main St. W., Hamilton,

ON, Canada, L8S 4M1

cDepartment of Chemistry, University of St Andrews, St Andrews UK, KY16 9ST

An oxidative strategy has been successful for the generation of a variety of dichalcogenides with acyclic or spirocyclic structures from the corresponding dichalcogenido PNP-bridged monoanions.[1] Application of this methodology to the known P2N2-bridged dianions [EP2N2E]2- [E = S, Se, Te: P2N2 = (tBuN)P(μ-NtBu)2P(NtBu)][2,3] produces novel polychalcogen macrocycles, e.g. the trimers [-P2N2-(μ-E-E-)]3 (E = S, Se) in which a planar P6E6 motif incorporating dichalcogenido groups is stabilized by P2N2 scaffolds.[4] The NMR spectra (solution and solid state) and X-ray structures of these novel polychalcogen macrocycles will be discussed in the context of DFT calculations. The extension of this chemistry to the formation of phosphorus-tellurium rings will also be described. [1] For a review, see T.Chivers, J. S. Ritch, S. E. Robertson, J. Konu and H. M. Tuononen, Acc. Chem.

Res. 2010, 43, 1053. [2] T. Chivers, M. Krahn, M. Parvez and G. Schatte, Inorg. Chem., 2001, 40, 1493. [3] G. Briand, T. Chivers and M. Parvez, Angew. Chem. Int. Ed., 2002, 41, 3468. [4] A. Nordheider, T. Chivers, R. Thirumoorthi, I. Vargas-Baca and J. D. Woollins, Chem. Commun.,

2012, 48, 6346.

Oral 10

IRIS-13 Victoria

44

Molecular Compounds with Bonds Between Heavier Group 15 Elements, Synthesis, Structures and Properties

C. von Hänisch and S. Traut

(haenisch@chemie.uni-marburg.de) Philipps-Universität-Marburg, Germany

Homoatomic ring and cage compounds of the group 15 elements are well known for several years,[1] whereas heteroatomic rings and cages of these elements are rarely described in literature. Recently, Burford and co-workers reported some cationic compounds with bonds between different group 15 elements.[2] In this talk, our results on the synthesis of neutral molecular compounds with bonds between heavier group 15 elements will be presented. Such species were obtained from the reaction of silyl or lithium functionalised phosphines or arsines with metal chlorides such as ECl3 or RECl2 (E = As, Sb, Bi; R = (Me3Si)2CH, (Me3Si)3C).[3]

Figure 1 Molecular structures of the compounds [tBu2PhSiAs{BiClCH(SiMe3)2}2] (left) and

[As2{BiClCH(SiMe3)2}4] (right) obtained from the reaction of (Me3Si)2CHBiCl2 with tBu2PhSiAs(SiMe3)2 and As(SiMe3)3, respectively.

[1] a) M. Baudler, Angew. Chem. 1987, 99, 429-451; b) L.Balázs, H. J. Breunig, Coord. Chem. Rev.

2004, 248, 603-621; c) M. Westerhausen, S. Weinrich, P. Mayer, Z. Anorg. Allg. Chem. 2003, 629, 1153-1156; d) G. Linti, W. Köstler, Z. Anorg. Allg. Chem. 2002, 628, 63-66.

[2] a) E. Conrad, N. Burford, R. McDonald, M. J. Ferguson, Inorg. Chem. 2008, 47, 2952-2954; b) E. Conrad, N. Burford, R. McDonald, M. J. Ferguson, J. Am. Chem. Soc. 2009, 131, 5066-5067; c) E. Conrad, N. Burford, R. McDonald, M. J. Ferguson, Chem. Commun. 2010, 46, 4598-4560.

[3] a) D. Nikolova, C. von Hänisch, Eur. J. Inorg. Chem. 2005, 378-382; b) C. von Hänisch, D. Nikolova, Eur. J. Inorg. Chem. 2006, 4770-4773; c) C. von Hänisch, S. Stahl, Z. Anorg. Allg. Chem. 2009, 635, 2230-2235; d) S. Traut, A. P. Hähnel, C. von Hänisch, Dalton Trans. 2011, 40, 1365-1371.

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Manipulation of Low Coordinate Phosphorus Environments

N. S. Townsend and C. A. Russell (nell.townsend@bristol.ac.uk)

School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK Main group chemistry which mimics that of carbon is key to expanding the boundaries of both inorganic and organic chemistry. The isolobal relationship between a CH moiety and a P atom has been used in predicting and rationalizing many novel compounds. Tert-butylphosphaalkyne, P≡CtBu, is commonly worked with due to its relative ease of synthesis on a large scale and its isolobal relationship to an alkyne, which of course are abundant, versatile substrates in organic synthesis.[1] As with alkynes, oligomerisation can occur and one particular oligomer of interest is 2,4,6-tri-tertbutyl-1,3,5-triphosphabenzene. These six-membered rings with aromatic character are isolobal to benzene and thus would be expected to mimic the diverse chemistry of the prototypical aromatic compound. However, the presence of phosphorus in the aromatic ring leads to additional reaction possibilities such as coordination through the phosphorus lone pair.

Figure 3 Novel species derived from 2,4,6-tri-tertbutyl- 1,3,5-triphosphabenzene.

The work presented expands upon the coordination of this interesting ligand, demonstrating the unusual ŋ1 coordination mode.[2,3] Furthermore, the addition of reactive main group moieties based on pnictenium ions, which are isolable to carbenes, is investigated leading to rare examples of cationic P/C cages. Novel P/C cages are also accessible via the reaction of P≡CtBu with these reactive pnictenium species. [1] Becker, G.; Schmidt, H.; Uhl, G.; Uhl, W., Inorg. Synth. 1990, 27, 243. [2] Clenndenning, S. B.; Hitchcock, P. B.; Nixon, J. F., Chem. Commun. 1999, 1377. [3] Townsend, N. S.; Green, M.; Russell, C. A., Organometallics, 2012, 31, 2543.

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Bond-Selective Cleavage in Oxaphosphirane Complexes

Rainer Streubel (r.streubel@uni-bonn.de)

Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms Universität Bonn Gerhard-Domagk Str. 1, 53121 Bonn, Germany

Whereas unligated oxaphosphiranes possessing a 3

3-phosphorus (I) are still unknown, their com-plexes

II have been reported in the early nineties.[1,2] The development of a new and facile protocol for the synthesis of oxaphosphirane complexes using Li/Cl phosphinidenoid complexes[3] paved the way to a broad systematic study and, hence, a wealth of new structures became available.

This report will present the scope of this methodology[4] including investigations of reaction courses that lead to oxaphosphirane complexes. Furthermore, we will address the problem of bond-selective reactions of complexes II using various substrates[5] while focussing on endocyclic bonds (i-iii). In the last part, we will present first investigations on exocyclic bond cleavages (iv-v) in II,[6] thus entering the new areas of P-functional complexes (via iv) and free oxaphosphiranes (via v). Further-more, we will provide first examples of deoxygenation processes of complexes II which formally represent a combination of i) and ii).[7]

Scheme: Oxaphosphiranes I and complexes II (M = Cr-W; R1 = alkyl; R2, R3 = alkyl, aryl) [1] Bauer, S.; Marinetti, A.; Ricard, L.; Mathey, F.; Angew. Chem. 1990, 102, 10, 1188. [2] Streubel, R.; Kusenberg, A.; Jeske, J.; Jones, P. G.; Angew. Chem. 1994, 106, 2564. [3] a) Özbolat-Schön, A.; von Frantzius, G.; Marinas Pérez, J.; Nieger, M.; Streubel, R.; Angew. Chem. Int. Ed. 2007, 46, 9327; b) Bode, M.; Daniels, J.; Streubel, R.; Organometallics 2009, 28, 4636. [4] a) Streubel, R.; Bode, M.; Marinas Pérez, J.; Schnakenburg, G.; Daniels, J.; Jones, P. G.; Z. Anorg. Allg. Chem. 2009, 635, 1163; b) Albrecht, C.; Bode, M.; Marinas Pérez, J.; Schnakenburg, G.; Streubel, R.; Dalton Trans. 2011, 40, 2654; c) Marinas Pérez, J.; Klein, M.; Kyri, A.; Schnakenburg, G.; Streubel, R.; Organometallics 2011, 30, 5636; d) Streubel, R.; Schneider, E.; Schnakenburg, G.; submitted. [5] a) Helten, H.; Marinas Pérez, J.; Schnakenburg, G.; Streubel, R.; Organometallics, 2009, 28, 1221; b) Marinas Pérez, J.; Helten, H.; Donnadieu, B.; Reed, C. A.; Streubel, R.; Angew. Chem. Int. Ed. 2010, 49, 2615; c) Marinas Pérez, J.; Albrecht, C.; Helten, H.; Schnakenburg, G.; Streubel, R.; Chem. Commun. 2010, 46, 7244; d) Marinas Pérez, J.; Helten, H.; Schnakenburg, G.; Streubel, R.; Chem. Asian J. 2011, 6, 1539. [6] Espinosa, A.; Streubel, R.; submitted. [7] Albrecht, C.; Shi, L.; Marinas Pérez, J.; van Gastel, M.; Schwieger, S.; Neese, F.; Streubel, R.; submitted.

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Insights into the Mechanisms of Metal-Free Hydrogen Transfer between Amine-Boranes and Aminoboranes and Diborazane Redistribution:

Implications for Polyaminoborane Synthesis

Erin M. Leitao, Alasdair P. M. Robertson, Naomi E. Stubbs, Guy C. Lloyd-Jones, and Ian Manners (chzeml@bristol.ac.uk, ian.manners@bristol.ac.uk)

School of Chemistry, University of Bristol, Cantock’s Close, BS8 1TS, UK Over the past decade, the development of amine-borane (RR’NH∙BH3, R = R’ = H or alkyl) dehydrogenation chemistry has accelerated due to the use of these adducts as precursors to boron-nitrogen containing polymers, in addition to their potential as hydrogen storage and transfer materials.[1] Polyaminoboranes, [RHN-BH2]n (R = alkyl), isoelectronic analogues of linear polyolefins [RHC-CH2]n, one of the most important synthetic polymers today, are an exciting class of main-group polymers with potentially interesting properties. These polymers have recently become accessible from a limited range of amine-borane adducts, facilitated by an iridium catalyst under mild conditions.[2] However, in order to increase the scope through polymerization of a wider variety of monomers, the mechanism of catalysis must be fully probed and understood. This is explored by studying simpler systems, such as the remarkable metal-free hydrogen transfer between aminoboranes (RR’N=BH2, R = R’ = alkyl) and amine-boranes as well as model linear diborazanes (RR’NH-BH2-NRR’-BH3, R = R’ = H or alkyl), at room temperature, thermolytically, and catalytically.[3] This presentation will communicate pertinent mechanistic details of the hydrogen transfer and redistribution processes, relevant to the formation of polyaminoboranes.

iPr2N=BH2

Me2NHįBH3

+1/2[Me2N-BH2]2

+

iPr2NHįBH2iPr2NHįBH3

+

Me2N-BH2

MeNH2-BH2-NHMe-BH3 MeNH2įBH3 + MeNH=BH2

[1] Staubitz, A. et al. Chem. Rev. 2010, 110, 4023. Whittell, G.; Manners, I. Angew. Chem. Int. Ed. 2011, 50, 10288. Staubitz, A. et al. Chem. Rev. 2010, 110, 4079.

[2] Staubitz, A. et al. Angew. Chem. Int. Ed. 2008, 47, 6212. Staubitz, A. et al. J. Am. Chem. Soc. 2010, 132, 13332.

[3] Robertson, A. P. M. et al. J. Am. Chem. Soc. 2011, 133, 19322.

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Chemistry of Dimolybdaheteroboranes Containing group 16 Elements

Kiran Kumar Varma Chakrahari and Sundargopal Ghosh (sghosh@iitm.ac.in)

Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India

Pyrolysis of [(Cp*Mo)2B4H8], (Cp* = η5-C5Me5), a possible intermediate generated by the reaction of [Cp*MoCl4] and [LiBH4.thf] at -40 ºC, with chalcogen sources yielded [(Cp*Mo)2B4H6E], (where E = S, Se and Te). Cluster [(Cp*Mo)2B4H6E] on reaction with [Fe2(CO)9] led to the formation of [(Cp*Mo)2B4H6EFe(CO)3]. Further, a new class of metallaheteroborane clusters, oblatocloso-[(Cp*Mo)2B3H3S(-CO)3Co2(CO)3] and hypoelectronic [(Cp*Mo)2B4H4S(3-CO)Co2(CO)4] have been isolated from the reaction of [(Cp*Mo)2B4H6E] with [Co2(CO)8]. The geometry of cluster [(Cp*Mo)2B3H3S(-CO)3Co2(CO)3] is unique, which can be generated from a 8 vertex closo-dodecahedron by performing two diamond-square-diamond (dsd) rearrangements. The key results of this work will be discussed.

[1] Aldridge, S.; Shang, M.; Fehlner, T. P. J. Am. Chem. Soc. 1998, 120, 2586. [2] Dhayal, R. S.; Chakrahari, K. K. V.; Varghese, B.; Mobin, S. M.; Ghosh, S. Inorg. Chem. 2010, 49,

7741. [3] Chakrahari, K. K. V.; Ghosh, S. J. Chem. Sci. 2011, 123, 847.

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Transition Metal Anion Reagents for the Preparation of Inorganic and (Phospha)organometallic Ring Systems

Robert Wolf,a,b Eva-Maria Schnöckelborg,b Jennifer Malberga and Katharina Weberb

(robert.wolf@ur.de)

a University of Regensburg, Institute of Inorganic Chemistry, Universitätsstr. 31, 93053 Regensburg, Germany

b University of Münster, Institute of Inorganic and Analytical Chemistry, Corrensstraße 30, 48149 Münster, Germany

Our research group investigates anionic polyarene transition metal complexes that may be used as synthetic equivalents of transition metal anions. Only few representatives of this promising class of compounds have previously been reported.[1] In this contribution, we describe the synthesis and characterisation of the new iron complex [K(18-Krone-6){Cp*Fe(η4-C10H8)}] (1, Cp* = C5Me5).[2] Selected synthetic applications of this complex and related metalates are discussed. The synthetic potential of such reagents is demonstrated by the reaction of „Cp*Fe equivalent” 1 with white phosphorus, which gave unusual anionic polyphosphido iron complexes 2 and 3 under mild conditions.[3]

[1] a) Review: J. E. Ellis, Inorg. Chem. 2006, 45, 3167-3186; b) recent examples: R. E. Jilek, M. Jang, E.

D. Smolensky, J. D. Britton, J. E. Ellis, Angew. Chem. Int. Ed. 2008, 47, 8692-8695, and refs. therein.

[2] R. Wolf, E.-M. Schnöckelborg, Chem. Commun. 2010, 46, 2832-2834. [3] E.-M. Schnöckelborg, J. J. Weigand, R. Wolf, Angew. Chem. Int. Ed. 2011, 50, 6657-6660.

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Synthesis and Characterization of Ligand-Modified Aluminium Alkoxide

Hameed Ullah Wazir†‡ and Michael Veith†

(hameedwazir@yahoo.co.uk) †Institute of Inorganic and General Chemistry, University of Saarland, 66125 Saarbruecken Germany

‡Department of Chemistry Hazara University Mansehra 21300, KPK, Pakistan Development of designed molecular compounds of metals is of significant interest as single source precursors (SSPs) in material synthesis, specifically in synthesis of functional metal oxides. However, certain variable parameters hinder the development of the designed compounds. These variables include reaction temperature and time, nature of central metal atoms, solvents and ligands etc. Therefore, it is reasonable to say that a good control over these parameters assures the materialization of the designed SSPs. We have tested this hypothesis by synthesizing liagand-modified aluminum alkoxides of the general formula, [XxAl(OR)y-x]n, where X = Hˉ (1, 2) and Clˉ(3), R=cyclohexyl (1, 2) and 1-methylcyclohexyl (3), x varies from 1-2 and n=2 (3), 5 (1) and n (2) . The novel compounds, 1, 2, and 3 were synthesized under varying reaction conditions using ligands of different bulk. The compounds 1, 2, and 3 were all obtained as colorless crystals in the parent solvent upon storing in refrigerator at -30°C. The Al–H bonds in the compounds 1 and 2 were confirmed by measuring their IR spectra, which give characteristic peaks ranging between 1830 cm-1 to 1865 cm-1.[1] The structures in solution of the compounds 1, 2, and 3 were determined by 1H- and 13C-NMR spectroscopy. MAS-NMR spectrum was recorded for compound 2 which is in good agreement to the solid state structure determined by single crystal X-rays analysis. The compounds were analyzed by single crystal X-rays diffraction and solid state structures were established for 1, 2, and 3. Compound 1 is pseudo pentamer while compound 2 is a two dimensional polymer. Here, it is important to note that the reactants and their stoichiometries were kept same during the synthesis of compounds 1 and 2. However, by varying the rate of dropping alcohol into the reaction mixture (3LiAlH4 + AlCl3) and the reaction time, two different compounds 1 and 2 were obtained. Compound 3 is dimer having central four-membered Al2O2 cyclic ring. The lower degree of polymerization in compound 3 is attributed to the bulky Clˉ ligand substituted for Hˉ and more sterically crowded 1-methylcyclohexoxy group. The elemental compositions of the compounds 1, 2, and 3 were determined using CHN analyzer for carbon and hydrogen. The experimentally determined carbon and hydrogen contents of the compounds 1, 2, and 3 were in good agreement to that calculated theoretically. The aluminum contents of the compounds 1, 2, and 3 were determined by complexometric titration method using EDTA as complexing agent while the chlorine in compound 3 was determined by titrimetry with AgNO3.[2-3] [1] M. Veith, S. Faber, H. Wolfanger and V. Huch, Chem. Ber., (1996), 129, 381. [2] Komplexometrische Bestimmungsmethoden mit Titriplex, Merck, 3. Auflage. [3] E. Gerdes, Qualitative Anorganische Analyse, Verlag Vieweg, 1995.

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Synthesis and Properties of Phosphole-Based Smart Molecular Materials

Yi Ren and Thomas Baumgartner (thomas.baumgartner@ucalgary.ca)

Department of Chemistry, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada

Phosphole-based -conjugated compounds have recently attracted significant attention, due their unique electronic properties.[1] The materials have shown considerable potential for a variety of practical applications, such as organic light-emitting diodes, field-effect transistors, and solar cells. Equally desirable for practical applications are highly ordered bulk phases of the materials, and self-assembly features have been found to play an important role in the efficient charge-, ion-, and charge-transfer properties of organic electronics. This presentation will highlight our efforts in efficiently designing ring-fused phosphole building blocks that provide access to smart molecular materials.[2] Our multi-pronged approach addresses their intrinsic properties, such as electronics and photophysics, but also some extrinsic properties that have opened up a path to utilizing these functional building blocks in the generation of highly ordered nano/microstructures.

[1] (a) M. G. Hobbs, T. Baumgartner, Eur. J. Inorg. Chem. 2007, 3611. (b) Y. Matano, H. Imahori, Org.

Biomol. Chem. 2009, 7, 1258. [2] (a) Y. Ren, W. H. Kan, M. A. Henderson, P. G. Bomben, C. P. Berlinguette, V. Thangadurai, T.

Baumgartner, J. Am. Chem. Soc. 2011, 133, 17014. (b) Y. Ren, W. H. Kan, V. Thangadurai, T. Baumgartner, Angew. Chem. Int. Ed. 2012, 51, 3964.

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Diazastanna Four-Membered Rings

Tomas Chlupaty, Ales Ruzicka, Zdenka Padelkova and Hana Vankatova (tom-mail@seznam.cz)

Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, CZ-532 10, Pardubice, Czech Republic

Two possible pathways of forming of diazastanna four-membered rings via delocalization of -electrons over the whole fundamental NCN skeleton of formamidinato/amidinato/guanidinato unit are known.[1] The first direct route is based on the nucleophilic addition of stannylenes (especially Lappert´s type) to starting N,N´-disubstituted carbodiimides. The second one is the substitution reaction of lithium (or other group 1 or 2 elements) precursor[2] with tin halide (in molar ratio 1:1/2:1) via salt elimination of lithium halide (or group 1 or 2 halide). These tin containing compounds can be used in further reactivity, for example oxidative addition on the metal center,[3] substitution of ligands and many many others. To the best of our knowledge the modern and sophisticated application is an activation of small (or larger) molecules by the help of formamidinato-/amidinato-/guanidinatotin cycles as a substrate.[4] The characterization of synthesized compounds was realized by XRD techniques and multinuclear NMR spectroscopy.

Figure 1. The molecular structure of one of the compounds studied The authors would like to thank the Czech Science Foundation (grant nr. P207/12/0223) for financial support. [1] Nimitsiriwat, N.; Gibson, V. C.; Marshall, E. L.; White, J. P.; Daleb, S. H.; Elsegood, M. R. J. Dalton

Trans. 2007, 4464; Sen, S. S.; Kritzler-Kosch, M. P.; Nagendran, S.; Roesky, H. W.; Beck, T.; Pal, A.; Herbst-Irmer, R. Eur. J. Inorg. Chem. 2010, 5304.

[2] Chivers, T.; Fedorchuk, C.; Parvez, M. Inorg. Chem. 2004, 43, 2643. [3] Foley, S. F.; Yap, G. P. A.; Richeson, D. S. J. Chem. Soc., Dalton Trans. 2000, 1663. [4] Chlupaty, T.; Padelkova, Z.; DeProft, F.; Willem, R.; Ruzicka, A. Organometallics 2012, 2203.

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Conjugated Boracycles: Electron-Deficient Ring Systems

Pangkuan Chen, Jiawei Chen, Didier A. Murillo and Frieder Jäkle (fjaekle@rutgers.edu)

Department of Chemistry, Rutgers University – Newark, Newark, NJ 07302\

Electron-deficient organoboranes play important roles in various organic transformations, as activators of transition metal complexes in olefin polymerization, and in the activation of small molecules when combined with bulky Lewis bases (so-called frustrated Lewis pairs). The Lewis acidic properties are also exploited in the recognition of anions. Especially attractive are bidentate and polyfunctional species, which tend to exhibit the strongest affinities due to cooperative and/or chelate effects. Conjugated systems that feature multiple tricoordinate borane moieties, on the other hand, are attractive in optical and electronic applications (e.g. nonlinear optics, luminescent imaging materials, OLEDs, OFETs, photovoltaics), due to extension of conjugation via the empty p-orbital and the electron-acceptor effect of boranes.[1] In this presentation we will discuss our efforts toward conjugated cyclics in which multiple electron-deficient boranes interact with each other through -conjugated organic or organometallic bridging groups.[2,3] Among these is the intriguing new class of boracyclophanes and related macrocycles that are highly electron-deficient, yet can be switched into electron-rich systems by anion coordination.[3]

[1] W. E. Piers, G. J. Irvine, V. C. Williams, Eur. J. Inorg. Chem. 2000, 2131. F. Jäkle, “Boron: Organoboranes” in Encyclopedia of Inorganic Chemistry, 2nd edition, Ed. B. King, Wiley-VCH, Weinheim, 2005; pp 560-598. D. W. Stephan, G. Erker, Angew. Chem., Int. Ed. 2009, 49, 46. C. R. Wade, A. E. J. Broomsgrove, S. Aldridge, F. P. Gabbai, Chem. Rev. 2010, 110, 3958. F. Jäkle, Chem. Rev. 2010, 110, 3985-4022

[2] K. Venkatasubbaiah, T. Pakkirisamy, A. Doshi, R. A. Lalancette, F. Jäkle, Dalton Trans. 2008, 4507-4513; T. Pakkirisamy, K. Venkatasubbaiah, W. S. Kassel, A. L. Rheingold, F. Jäkle, Organometallics 2008, 27, 3056-3064; T. Pakkirisamy, J. Chen, R. A. Lalancette, F. Jäkle, Organometallics 2011, 33, 6734-6741; J. Chen, Didier A. Murillo, R. A. Lalancette, F. Jäkle, unpublished results.

[3] P. Chen, R. A. Lalancette, F. Jäkle, J. Am. Chem. Soc. 2011, 133, 8802-8805; P. Chen, F. Jäkle, J. Am. Chem. Soc. 2011, 133, 20142-20145; P. Chen, R. A. Lalancette, F. Jäkle, 2012, submitted.

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Synthesis and Properties of 1-Phospha-2-boraacenaphthene

Takahiro Sasamori,1 Akihiro Tsurusaki,1 Atsushi Wakamiya,1,2 Kazuhiro Nagura,2 Stephan Irle,2 Shigehiro Yamaguchi2 and Norihiro Tokitoh1

(sasamori@boc.kuicr.kyoto-u.ac.jp) 1Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, JAPAN

2Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya 464-8602, Japan

Combinations of group 13 and 15 elements have attracted much attention in recent years from the viewpoint of material science such as -electron conjugated molecules.[1] In such series with both phosphorus and boron atoms, phosphaborine[2a] and phosphonium- and borate-bridged stilbene[2b] have been reported. On the other hand, we have recently reported the synthesis and properties of 1,2-dimesityl-1-phospha-2-boraacenaphthene (1), which is a unique heterocyclic compound bearing a P−B bond tethered with a naphthyl unit at the 1,8-positions.[3] We report here the synthesis and properties of the first stable 1-phospha-2-boraacenaphthene 1. Reduction of 1-dimesitylboryl-8-dichlorophosphinonaphthalene 2 with magnesium metal in THF at r.t. gave 1-phospha-2-boraacenaphthene 1 as orange crystals in 91% yield via the migration of the Mes group from the B atom to the P atom. The structure of 1 was characterized by the spectroscopic and X-ray crystallographic analyses. It is worth noting that 1 was found to be orange in color, both in the crystalline state and in solution, in contrast to the previously reported phosphinoboranes, which are colorless or yellow crystals. Furthermore, 1 exhibited weak but apparent orange emission in solution. The chemical and physical properties of 1 will be discussed in detail.

[1] A. Fukazawa, S. Yamaguchi, Chem. Asian J. 2009, 4, 1386. [2] a) T. Agou, J. Kobayashi, T. Kawashima, Org. Lett. 2005, 7, 4373. b) A. Fukazawa, H. Yamada, S.

Yamaguchi, Angew. Chem. Int. Ed. 2008, 47, 5582. [3] A. Tsurusaki, T. Sasamori, A. Wakamiya, S. Yamaguchi, K. Nagura, S. Irle, N. Tokitoh, Angew.

Chem. Int. Ed. 2011, 50, 10940.

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Exploring Non-Covalent Interactions and Hypervalency: Reactions of Acenaphthene Chalcogen Compounds

Fergus R. Knight, Rebecca A. M. Randall, Kasun S. Athukorala Arachchige, Lucy Wakefield, L. K.

Aschenbach, D. B. Cordes, A. Baggott, John M. Griffin, Sharon E. Ashbrook, Michael Bühl, Alexandra M. Z. Slawin and J. Derek Woollins (frk@st-andrews.ac.uk)

EaStCHEM, School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK The interaction of atoms is an integral aspect of chemistry, biology and materials science. Whilst there have been great advances in the knowledge of covalent and ionic bonding, ambiguity over “hypervalent” species still remains a topic of interest and a full understanding of non-covalent interactions has yet to be developed. When bulky heteroatoms are constrained in unavoidably congested environments, non-bonded interactions arise as a consequence of a direct overlap of orbitals. Such bonding situations can be accomplished by positioning members of Groups 16 and 17 at suitable locations in a rigid organic framework, for example naphthalene and related 1,2-dihydroacenaphthylene (acenaphthene). Acenaphthene compounds (Acenap[X][EPh] (Acenap = acenaphthene-5,6-diyl; X = Br, I; E = S, Se, Te) and Acenap[EPh][E`Ph] E/E` = S, Se, Te) experience a general increase in peri-separation for molecules accommodating heavier congeners and maps the trends observed previously for analogous naphthalene derivatives.[1,2] Nevertheless, conformation of the aromatic ring systems dominates the geometry of the peri-region, with the anomalies observed correlated to the ability of the frontier orbitals of the halogen or chalcogen atoms to take part in attractive or repulsive interactions.[1,2] The parent chalcogen compounds react with dibromine and diiodine acceptors to afford a group of structurally diverse addition products containing hypervalent three-body fragments; insertion adducts (X-R2Te-X) exhibiting molecular see-saw geometries, neutral charge-transfer (CT) spoke adducts (R2Se-I-I), bromoselanyl cations [R2Se-Br]+···[Br-Br2]-.[3] Reaction with methyl triflate afforded a series of monocation chalconium salts containing quasi-linear three-body CMe-E···Z (E = Te, Se, S; Z = Br/E) fragments, confirmed by DFT as the onset of three-center, four-electron bonding. The increasingly large J values for Se-Se, Te-Se and Te-Te coupling observed in the 77Se and 125Te NMR spectra give further evidence for the existence of a weakly-attractive through-space interaction.[4] ‘Electrochemically informed synthesis’ led to the oxidation of ditellurium compound Acenap(TePh)2 with AgBF4 and AgOTf affording two dication salts.[5] Similar reactions with derivatives containing lighter members of Group 16 afforded a series of silver(I) coordination compounds, generating 3D metal-organic frameworks (MOFs), 1D polymeric chains and simple monomeric complexes.[6]

[1] F. R. Knight, A. L. Fuller, M. Bühl, A. M. Z. Slawin and J. D. Woollins, Chem. Eur. J., 2010, 16, 7503; F. R. Knight, A. L. Fuller, M. Bühl, A. M. Z. Slawin and J. D. Woollins, Chem. Eur. J., 2010, 16, 7605. [2] L. K. Aschenbach, F. R. Knight, R. A. M. Randall, D. B. Cordes, A. Baggott, M. Bühl, A. M. Z. Slawin and J. D. Woollins, Dalton Trans., 2012, 41, 3141. [3] F. R. Knight, K. S. Athukorala Arachchige, R. A. M. Randall, M. Bühl, A. M. Z. Slawin and J. D. Woollins, Dalton Trans., 2012, 41, 3154. [4] F. R. Knight, R. A. M. Randall, K. S. Athukorala Arachchige, L. Wakefield, J. M. Griffin, S. E. Ashbrook, M. Bühl, A. M. Z. Slawin and J. D. Woollins, 2012, J. Am. Chem. Soc., submitted. [5] R. T. Boeré, T. L. Roemmele, L. K. Aschenbach, R. A. M. Randall, F. R. Knight, M. Bühl, A. M. Z. Slawin and J. D. Woollins, unpublished work. [6] F. R. Knight, R. A. M. Randall, L. Wakefield, A. M. Z. Slawin and J. D. Woollins, Chem. Eur. J., submitted.

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Synthesis, Structures and Reactions of Stannylene-bridged Ru Complexes Derived from Tetraethyldilithiostannole

Masaichi Saito,a Takuya Kuwabara,a Jing Dong Guo,b Shigeru Nagaseb

(masaichi@chem.saitama-u.ac.jp) aDepartment of Chemistry, Graduate School of Science and Engineering, Saitama University, Shimo-

okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan bFukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho, Sakyou-ku,

Kyoto, 606-8103, Japan

Group 14 metallole anions and dianions have received considerable attention in terms of their aromaticity and their potential usefulness as ligands for transition metal complexes.[1] There have already been reported several transition metal complexes coordinated by metallole ligands in 5 fashions,[2] which were synthesized by the reactions of monoanion equivalents of metalloles with transition metal reagents. In contrast, there are no reports on the reactions of dianion equivalents of metalloles with transition metal reagents. We therefore examined the reactions of dilithiotetraphenylstannole[3] with various transition metal reagents. However, no identifiable products were obtained. We next investigated the reactions of tetraethyldilithiostannole 1[4] with [Cp*RuCl]4, and unexpected products were produced. After addition of diethyl ether to a mixture of tetraethyldilithiostannole 1 and [Cp*RuCl]4 (0.5 eq), bis(stannylene)-bridged dinuclear Ru complex 2 was isolated in 13% yield. To investigate the mechanism for the formation of 2, the reaction of 1 with 0.2 equivalent of [Cp*RuCl]4 was examined, and dilithiobis(stannylene)-bridged dinuclear Ru complex 3 was isolated in 80% yield. The nature of the RuRu bonds in 2 was clarified by theoretical calculations.

[1] For example of recent reviews, see: (a) Saito, M.; Yoshioka, M. Coord. Chem. Rev. 2005, 249, 765.

(b) Lee, V. Y.; Sekiguchi, A. Angew. Chem., Int. Ed. 2007, 46, 6596. (c) Lee, V. Y.; Sekiguchi, A. In Organometallic Compounds of Low-coordinate Si, Ge, Sn and Pb, Wiley, Chichester, p335. (d) Saito, M. Coord. Chem. Rev. 2012, 256, 627.

[2] (a) Freeman, W. P.; Tilley, T. D.; Rheigold, A. L.; Ostrander, R. L. Angew. Chem., Int. Ed. Engl. 1993, 32, 1744. (b) Freeman, W. P.; Tilley, T. D. J. Am. Chem. Soc. 1994, 116, 8428. (c) Dysard, J. M.; Tilley, T. D. J. Am. Chem. Soc. 1998, 120, 8245. (d) Dysard, J. M.; Tilley, T. D. J. Am. Chem. Soc. 2000, 122, 3097. (e) Freeman, W. P.; Dysard, J. M.; Tilley, T. D. Organometallics 2002, 21, 1734. (f) Lee, V. Y.; Kato, R.; Sekiguchi, A.; Krapp, A.; Frenking, G. J. Am. Chem. Soc. 2007, 129, 10340. (g) Yasuda, H.; Lee, V. Y.; Sekiguchi, A. J. Am. Chem. Soc. 2009, 131, 9902.

[3] Saito, M.; Haga, R.; Yoshioka, M.; Ishimura, K.; Nagase, S. Angew. Chem., Int. Ed. 2005, 44, 6553. [4] Saito, M.; Kuwabara, T.; Kambayashi, C.; Yoshioka, M.; Ishimura, K. Nagase, S. Chem. Lett. 2010,

39, 700.

RuRu

SnSn

Et

Et

EtEtEtEt

Et

Et

Cp*

Cp*

1 2

Li

Ru

RuSn

Cp*

Cp*

Sn

EtEt

EtEt Et

Et

EtEt

Li

3

Sn

Et Et

Et Et

Li

Li

Oral 23

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N-alkylpyridine and Oxobenzene Bridged Bis-dithiazolyls: From Novel Rearrangements and Neutral Zwitterions to Synthetic Metals

A. Mailman, X. Yu, K. Lekin, S. M. Winter, J. Wong, A. R. Balo, R. Roberts and R. T. Oakley

(amailman@uwaterloo.ca) B. Department of Chemistry, University of Waterloo, Canada

The resonance stabilized pyridine bridged bis-dithiazolyls (1) are useful building blocks for the design of magnetic and conductive materials. These radicals are generally thermally stable in the solid state, and the modification of the ligands R1 and R2 and/or the external conditions (e.g. pressure, temperature) has led to a rich collection of both molecular and solid state structures. In comparison, the isoelectronic oxobenzene bridged bis-dithiazolyls (2) are a new class of radical where the modification of R3 and incorporation of the supramolecular synthon C=O has led to enhanced intermolecular interactions in the solid state and a dramatic improvement in conductivity. The preparation and characterization of new derivatives of 1 and 2 has been a significant challenge and recent results will be presented.

N

SS

NNS

S

R1

R2

SS

NNS

S

O

R21 2

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58

Exploring the Free Radical Reactivity of Cyclic Silylenes, Germylenes and Silenes using Muon Spin Spectroscopy

Robert West,a Amitabha Mitra,a Paul Percivalb,c and Jean-Claude Brodovitchb,c

(west@chem.wisc.edu) aOrganosilicon Research Center, University of Wisconsin, Madison WI 53706 USA

bDepartment of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada c TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada

The TRIUMF cyclotron facility in Vancouver BC is one of only four sites in the world capable of providing intense beams of spin-polarized positive muons suitable for muon spin resonance spectroscopy (µSR).[1,2] Positive muons are particles of antimatter, resembling protons but with mass about 1/9 of a proton. They have a lifetime of only 2.2 µs, decaying into positrons. Muons capture an electron to form muonium atoms, which can add to unsaturated molecules much like H atoms. The sample is placed in a magnetic field transverse to the muon spin polarization, so that the muon spins precess in similar manner to nuclei in NMR and electrons in ESR. The precession frequencies, which constitute the µSR spectrum, are derived from the time dependence of the angular distribution of positrons emitted on muon decay. The muon hyperfine splitting constant for a muoniated radical is readily obtained from frequency splitting in the µSR spectrum; this constant is a measure of the interaction between the muon and the unpaired electron, and provides structural and bonding information. We have studied the µSR spectra of free radicals formed by muonium addition to several cyclic silylenes, germylenes and silenes.[2,3] The results provide much information about the free-radical chemistry of cyclic silylenes and silenes, as well as new discoveries about the behavior of muon-containing molecules. [1] McKenzie, I.; Roduner, E., Using polarized muons as ultrasensitive spin labels in free radical

chemistry, Naturwissenschaften, 2009, 96, 873-887. [2] West, R.; Percival, P. W., Organosilicon Compounds Meet Suabtomic Physics: Muon Spin

Resonance, Dalton Trans., 2010, 39, 9209-9216. [3] McCollum, B. M.; Brodovitch, J.-C.; Clyburne, J. A. C.; Percival, P. W.; Tomasik, A. C.; West, R.,

Reaction of Stable N-heterocyclic Silylenes and Germylenes with Muonium, Chem.- Eur. J., 2009, 15, 8409-8412.

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Synthesis and Properties of Stannabenzenes

Norihiro Tokitoh, Yoshiyuki Mizuhata and Naoya Noda (tokitoh@boc.kuicr.kyoto-u.ac.jp)

Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan Aromatic hydrocarbons such as benzene and naphthalene are among the most fundamental class of organic compounds and play very important roles in organic chemistry. We have already succeeded in the synthesis and isolation of the first stable examples for neutral sila- and germaaromatic compounds (e.g. compounds 1 and 2) by taking advantage of kinetic stabilization afforded by an efficient steric protection group, Tbt and Bbt.[1] In view of the recent progress in the chemistry of sila- and germaaromatic compounds, the synthesis of stannaaromatic compounds is of great interest from the standpoint of systematic elucidation of the properties of metallaaromatic systems of heavier group 14 elements. Recently, we have succeeded in the synthesis and isolation of 2-stannanaphthalene 3 as a stable compound and revealed its high aromaticity.[2] However, neutral stannaaromatic compounds are still elusive and their properties have not been disclosed yet so far. We report here the synthesis of stannabenzenes 4 having a more fundamental stannaaromatic skeleton. Generation of stannabenzenes 4 was examined by the reaction of bulky bromostannanes 5 with lithium diisopropylamide in hexane at –40 °C. In the cases using 5a-c as a precursor, only [4 + 2] dimers 6a-c were observed at room temperature, indicating the generation of the corresponding stannabenzenes 4a-c.[3] Thus, the thermal stability of 4a and 4b was completely different from that of the sila- and germabenzenes bearing the same substituent. In the case using 5d as a precursor, on the other hand, NMR analysis of the reaction products at room temperature showed the co-existence of monomeric stannabenzene 4d together with the corresponding dimer 6d. The properties of stannabenzene 4d will be described along with an attempt at introducing an additional substituent to the stannabenzene ring.

[1] Tokitoh, N. Acc. Chem. Res. 2004,

37, 86. [2] a) Mizuhata, Y.; Sasamori, T.; Takeda, N.; Tokitoh, N. J. Am. Chem. Soc. 2006, 128, 1050. b)

Mizuhata, Y.; Sasamori, T.; Nagahora, N.; Watanabe, Y.; Furukawa, Y.; Tokitoh, N. Dalton Trans. 2008, 4409.

[3] Mizuhata, Y.; Noda, N.; Tokitoh, N. Organometallics 2010, 29, 4781.

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60

Free Radicals formed by H Atom Addition to Cyclic Carbenes, Silylenes and Germylenes

Paul Percival,a,b Graeme Langille,a Iain McKenzie a,b and Robert Westc

(percival@sfu.ca)

aDepartment of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada bTRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada

cOrganosilicon Research Center, University of Wisconsin, Madison WI 53706 USA Over the past few years we have studied the free radicals formed by H atom addition to carbenes, silylenes and germylenes. Our experimental method employs the exotic atom muonium, which is effectively a light isotope of hydrogen [1]. Muoniated radicals can be characterized by muon spin spectroscopy: muon spin rotation (µSR) to determine the muon hyperfine constant (hfc), and muon avoided level-crossing resonance (µLCR) to determine the hyperfine constants of other magnetic nuclei in the radical. We apply these techniques at the TRIUMF cyclotron facility, in Vancouver, the only site in the Americas with the necessary intense beams of spin-polarized muons. Our original focus was on radicals formed by H(Mu) addition to N-heterocyclic (NHC) ylidenes, as indicated below. However, we could not reconcile the muon hfcs of the radicals formed from silylenes with the predictions of quantum calculations. Part of the explanation lies in a coupling of the primary radical with a second silylene, so that a disilanyl product radical is observed [2]. This was confirmed in subsequent experiments on a series of NHC silylenes with different substituents on the nitrogens. The largest (diisopropylphenyl) served to slow the silyl coupling reaction so that we were able to detect the primary silyl radical, as evident from the muon hfc (931 MHz) [3]. The muon hfc in the primary silyl radical is much higher than for equivalent NHC alkyl (262 MHz, R = t-butyl) and germyl (650 MHz, R = t-butyl) radicals. The reasons for the non-intuitive order of hfcs will be discussed in terms of radical structure and dynamics. In particular, the lowest frequency vibrations are key to understanding the temperature dependence of the hfcs and the isotope effect on the muon/proton hfcs.

[1] R. West and P.W. Percival, Dalton Trans. 39, 9209-9216 (2010). [2] B.M. McCollum, J.-C. Brodovitch, J.A.C. Clyburne, P.W. Percival, A. Tomasik, R. West, Chem. Eur.

J. 15, 8409-8412 (2009). [3] A. Mitra, J.-C. Brodovitch, C. Krempner, P.W. Percival, P. Vyas and R. West, Angew. Chem. Int. Ed.

49, 2893-2895 (2010).

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New Homopolyatomic Sulfur Cations Stabilized by Halogenated Boron Clusters

Carsten Knapp, Janis Derendorf, Mathias Keßler and Christoph Bolli

(cknapp@uni-wuppertal.de) Fachbereich C – Anorganische Chemie, Bergische Universität Wuppertal, Gaußstr. 20, 42119

Wuppertal, Germany

Perhalogenated closo-dodecaborate anions [B12X12]2-(X = F, Cl, Br, I) are valuable weakly coordinating dianions for the stabilization of unusual cations and dications.[1] Improved syntheses for the perchlorinated dodecaborate [B12Cl12]2- were reported, which now make this anion available on a large scale.[2,3] The first solid diprotic super acid H2B12Cl12,[4] the strong methylating agent Me2B12Cl12,[5] and the silylium compounds (R3Si)2B12Cl12 [6] are useful reagents. Oxidation of [B12Cl12]2- leads to the radical anion [B12X12]•- and neutral B12Cl12, both being strong oxidizing agents themselves.[7]

Combining the [B12Cl12]2- anion with iodine and sulfur homopolyatomic cations followed by crystallization from supercritical sulfur dioxide lead to the isolation of salts containing the [I3]+ cation and the novel [S20]2+ and [S8]+ cations. The dication [S20]2+ has a structure similar to that of the known [S19]2+ and consists of two seven-membered sulfur rings bridged by a six-membered sulfur chain. The [S8]+ structure is similar that of [S8]2+ but contains a significantly longer transannular sulfur-sulfur contact. [1] C. Knapp, Comprehensive Inorganic Chemistry II 2012, in press. [2] V. Geis, K. Guttsche, C. Knapp, H. Scherer, R. Uzun, Dalton Trans. 2009, 2687. [3] W. Gu, O, V. Ozerov, Inorg. Chem. 2011, 50, 2726. [4] A. Avelar, F. S. Tham, C. A. Reed, Angew. Chem. Int. Ed. 2009, 48, 3491. [5] C. Bolli, J. Derendorf , M. Keßler, C. Knapp, H. Scherer, C. Schulz, J. Warneke, Angew. Chem. Int.

Ed. 2010, 49, 3536. [6] M Keßler, C. Knapp, V. Sagawe, H. Scherer, R. Uzun, Inorg. Chem. 2010, 49, 5223. [7] R. T. Boeré, S. Kacprzak, M. Keßler, C. Knapp, R. Riebau, S. Riedel, T. L. Roemmele, M. Rühle, H.

Scherer, S. Weber, Angew. Chem. Int. Ed. 2011, 50, 549.

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Polycyclic -Electron System with Boron at its Center

Shohei Saito, Kyohei Matsuo and Shigehiro Yamaguchi (s_saito@chem.nagoya-u.ac.jp.com)

Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan We disclose a new planarized triarylborane in which the tri-coordinated boron atom is embedded in a fully fused polycyclic -conjugated skeleton.[1] The compound 1 shows high stability toward oxygen, water, and silica gel, despite the absence of steric protection around the boron atom. Reflecting the electron-donating character of the -skeleton and the electron-accepting character of the boron atom, this compound shows broad absorption bands that cover the entire visible region and a fluorescence in the visible/near-IR region. In addition, this compound shows dramatic property changes upon formation of a tetracoordinated borate, such as thermochromic behavior in the presence of pyridine. Further studies on the application of this boron -system as well as the controlled synthesis of Boron-Doped Nanographene are currently underway in our laboratory.

[1] Saito, S.; Matsuo, K.; Yamaguchi, S. J. Am. Chem. Soc. 2012, 134, 9130. (highlighted in Spotlights)

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63

Donor-Acceptor Stabilization of Unusual Low Oxidation State Main Group Species: Placing Chemical Genies in a Bottle

Eric Rivard, Ibrahim Al-Rafia, Adam Malcolm, Michael Ferguson and Robert McDonald

(erivard@ualberta.ca) Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB, T6G 2G2,

Canada This talk will address the use of a general donor-acceptor protocol for the isolation of unusual main group hydrides, such as SiH2, GeH2 and SnH2 and the ethylene analogues H2SiEH2 (E = Ge and Sn) at ambient temperature.[1] In addition, we will detail our attempts to access stable complexes of unsaturated main group species such as BN and PN.[2] [1] (a) Thimer, K.; Al-Rafia, S. M. I.; Ferguson, M. J.; McDonald R.; Rivard, E. Chem. Commun. 2009,

7119. (b) Al-Rafia, S. M. I.; Malcolm, A. C.; Liew, S. K.; Ferguson, M. J.; Rivard, E. J. Am. Chem. Soc. 2011, 133, 777. (c) Al-Rafia, S. M. I.; Malcolm, A. C.; Liew, S. K.; Ferguson, M. J.; McDonald R.; Rivard, E. Chem. Commun. 2011, 6987. (d) Al-Rafia, S. M. I.; Malcolm, A. C.; McDonald R.; Ferguson, M. J.; Rivard, E. Angew. Chem., Int . Ed. 2011, 50, 8354. (e) Al-Rafia, S. M. I.; Malcolm, A. C,; McDonald R.; Ferguson, M. J.; Rivard, E. Chem. Commun. 2012, 1308.

[2] Al-Rafia, S. M. I.; Ferguson, M. J.; Rivard, E. Inorg. Chem. 2011, 50, 10543.

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Cu24 Rhombicuboctahedral Clusters with Oh Symmetry

Chen-Wei Liu (chenwei@mail.ndhu.edu.tw)

Department of Chemistry, National Dong Hwa University, Hualien, Taiwan 97401

While the geometry of rhombicuboctahedron, an Archimedean polyhedron composed of eighteen square faces and eight triangular faces (83 + 64 + 124), has been observed in metal organic polyhedral network structures, discrete metal clusters having this sort of ascetically pleasing structure, to the best of our knowledge, have never been identified. Herein we report the first Cu24 rhombicuboctahedral cluster formulated as [Cu24(S8)(H)15(S2CNR2)12]+ with Oh symmetry, a reduction product of hydrido copper clusters with borohydrides. Molecules of the type, [Cu8(4-H)(dtc)6]+, having a hydride-centered, tetracapped tetrahedral copper cluster topology, can be further reduced to yield Cu24 rhombicuboctahedral clusters. Their composition is primarily determined by ESI mass spectrometry and conformation by single crystal X-ray diffraction analysis. These highly symmetric molecules display an onion-type structure which consists of an idealized rhombicuboctahedral Cu24 core that is further surrounded by a truncated octahedral polyhedron consisting of twenty-four sulfur atoms from twelve dithiocarbamate (dtc) ligands. In addition, a catenated sulphur cage whose eight S atoms disorder dynamically at twelve positions of a cuboctahedron is trapped inside the Cu24 capsule. Finally neutron diffraction analysis clearly suggests there are eight three-coordinate (3-H) hydrides and six four-coordinate hydrides (4-H), which capped the eight triangular faces (83) and six square faces (64) of a rhombicuboctahedron, respectively.

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Dithienylethenes Containing Diazabutadiene Functionality and their Main Group Derivatives

Jacquelyn T. Price and Paul J. Ragogna (jprice6@uwo.ca pragogna@uwo.ca)

Department of Chemistry and the Center for Materials and Biomaterials Research Western University, 1151 Richmond St, London, Ontario, N6A 5B7, Canada

Within the past decade photochromic materials have received a large amount of interest because of their ability to function as potential photoswitchable molecular devices and optical memory storage systems.[1] Among these materials, diaryethenes have proven to have the greatest potential in this field because of their excellent fatigue resistance and thermal irreversibility.[2] There have been extensive studies focused on these systems containing mostly organic frameworks and only recently the coordination of these systems to transition metal centers, which enhance the stability of the photochromic system and modulate the photochromic reactivity has been explored.[3] While diazabutadiene ligands are well known for their ability to be redox active ligands, bind to transition metals[4] and support low valent, low oxidation state main group elements[5,6] there has been no report on the functionalization of this ligand type with diarylethenes. We have synthesized a new class of diazabutadiene ligands with photochromic thiophene rings in the backbone and have synthesized the borane and phosphine complexes. Their synthesis and ability to undergo reversible photochromic ring closing and opening reactions will be discussed.

[1] Feringa, B. L., Ed. Molecular Switches; Wiley-VCH: Weinheim, Germany, 1990. [2] Irie,

M. Chemical Reviews 2000, 100, 1685-1716. [3] Hasegawa, Y.; Nakagawa, T.; Kawai, T. Coordination Chemistry Reviews, 254, 2643-2651. [4] Van, K. G.; Vrieze, K. Adv. Organomet. Chem. 1982, 21, 151-239. [5] Gudat, D. Accounts of Chemical Research 2010, 43, 1307-1316.

[6] Asay, M.; Jones, C.; Driess, M. Chemical Reviews 2011, 111, 354-396.

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Large Effect of Subtle Building Defects on the Physical Properties of 2D Boron Layered “Tiling” Compounds

Takao Mori1-3, Ievgen Kuzmych-Ianchuk1, Kunio Yubuta4, Toetsu Shishido4, Shigeru Okada5, Kunio

Kudou6, Yurii Prots7 and Yuri Grin7

(mori.takao@nims.go.jp) 1National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, 305-0044 Japan

2Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, 739-8514 Japan

3University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 Japan 4Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 Japan

5Kokushikan University, 4-28-1 Setagaya, Tokyo, 154-8515 Japan 6Kanagawa University, 3-27-1 Rokkakubashi, Yokohama, 221-8686 Japan

7Max Planck Institute Chemical Physics of Solids, Nothnitzer Str. 40, 01187 Dresden, Germany Rare earth borides have yielded intriguing systems for f-electron physics and chemistry [1]. We have taken a systematic approach to the AlB2-type analogous “tiling” compounds, composed of 2D boron atomic sheets (based on hexagonal graphitic structure) sandwiching rare-earth (R) and transition metal (Tr) atoms (Fig. 1). By selecting unexplored combinations of metal constituents, synthesis of myriad new compounds of these structure types can be envisioned. [2] REAlB4 in particular has attracted attention with recent discoveries, such as frustrated magnetism in -HoAlB4 and ErAlB4,[3] and multiple magnetic anomalies in -TmAlB4 below the Neel temperature indicated to be due to building defects.[4] The two main structure types of REAlB4; - and - , simply differ in their in-plane “tiling” arrangement of [5] and [7] B rings. Tm2AlB6 with [5], [6], [7] B rings was also successfully synthesized and a magnetic field induced state with extreme stability versus field observed.[2] With a counterintuitive approach to crystal growth, single crystals of -TmAlB4 were successfully grown, which were indicated from TEM and advanced XRD analysis to be virtually free from the ubiquitous building defects. The physical properties show a striking difference from those of conventional -TmAlB4 crystals, and the large effect of the building defects on the physical properties could be directly confirmed, such as the origin of “missing entropy” [5]. These building defects are quite subtle and may in some cases be unperceived, and might possibly be the origin of anomalous behavior in other layered systems also. [1] e.g. T. Mori, in: Handbook on the Physics and Chemistry of Rare Earths, Vol. 38, North-Holland,

Amsterdam, 2008 p. 105-173. [2] T. Mori, T. Shishido, K. Nakajima, K. Kieffer, and K. Siemensmeyer, J. Appl. Phys. 105, 07E124

(2009), T. Mori, in: The Rare Earth Elements: Fundamentals and Application, J. Wiley & Sons, New York, in press (2012).

[3] T. Mori, J. Appl. Phys. 109, 07E111 (2011). [4] T. Mori, H. Borrmann, S. Okada, K. Kudou, A. Leithe-Jasper, U. Burkhardt, Yu. Grin, Phys. Rev. B

76, 064404 (2007). [5] T. Mori, I. Kuzmych-Ianchuk, K. Yubuta, T. Shishido, S. Okada, K. Kudou, Yu. Grin, J. Appl. Phys.

111 07E127 (2012).

Fig. 1 AlB2-type analogous “tiling” compounds

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New Oxyanions of Sulfur

S. Greer, F. Grein, F. Leblanc, A. Mailman, B.Müller, J. Passmore, T. A. P. Paulose, M. Rautiainen and S. Richardson

(passmore@unb.ca) Department of Chemistry, University of New Brunswick, Fredericton, NB, E3B 5A3, Canada

The binary oxyanions of sulfur were mostly prepared at least 100 years ago and are part of the backbone of basic chemistry of the elements and are of industrial importance. However we estimated that the energetics of reaction of sulfate and dithionite salts with SO2 become increasingly favorable as the size of the cation increases as shown in figure 1 leading to two new classes of oxyanions, the polythionites, (SO2)n 2- and the mixed S(VI) and S(IV) oxyanions, O3SO(SO2)n 2-. This also provides a new way to reversibly sequester SO2 an atmospheric pollutant. Our experimental results will be presented.

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68

Bis[N,N´-diisopropylbenzamidinato(–)]silicon(II): A Novel Donor-Stabilized Silicon(II) Species

R. Tacke, K. Junold, J. A. Baus, C. Burschka

(r.tacke@uni-wuerzburg.de)

Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, D-97074 Würzburg, Germany

Starting from the six-coordinate bis(amidinato)silicon(IV) complex 1, the novel three-coordinate bis(amidinato)silicon(II) compound 4 was synthesized by reductive HCl elimination. The donor-stabilized silylene 4 reacts with W(CO)6 as a nucleophile to give the five-coordinate silicon(II) compound 5. Treatment of 4 with I2, PhSe–SePh, N2O, S8, Se, or Te results in an oxidative addition to give the five- (6–9) and six-coordinate (2, 3) bis(amidinato)silicon(IV) complexes 2, 3, and 6–9. The studies reported here were performed in context with our systematic investigations on higher-coordinate silicon compounds (for recent publications, see refs. [1–4]).

Molecular structures of 4 (left), 5 (middle), and 7 (right) in the crystal.

[1] K. Junold, C. Burschka, R. Tacke, Eur. J. Inorg. Chem. 2012, 189–193. [2] C. Kobelt, C. Burschka, R. Bertermann, C. Fonseca Guerra, F. M. Bickelhaupt, R. Tacke, Dalton

Trans. 2012, 41, 2148–2162. [3] B. Theis, J. Weiß, W. P. Lippert, R. Bertermann, C. Burschka, R. Tacke, Chem. Eur. J. 2012, 18,

2202–2206. [4] K. Junold, J. A. Baus, C. Burschka, R. Tacke, DOI: 10.1002/ange.201203109; Angew. Chem. Int. Ed.

2012, DOI: 10.1002/anie.201203109.

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A Crystalline Room Temperature-stable Singlet Nitrene

Fabian Dielmann, Olivier Back, Martin Henry-Ellinger and Guy Bertrand (fabian.d@gmx.de)

Department of Chemistry, University of California, Riverside, Riverside, CA 92521-0403, USA

More than two decades after the discovery of the first stable carbene,[1] we report the isolation and full characterization of a nitrogen analogue, namely a nitrene.[2] The bonding situation is reminiscent to that of metallonitrenes (nitrido metal complexes), which have extensively been studied due to their implications in biological nitrogen fixation by the nitrogenase enzymes, and the industrial Haber-Bosch hydrogenation process of converting N2 into NH3. The reactivity of this novel compound will be discussed, e.g. we demonstrate that the nitrene can activate P4 and is capable of complete nitrogen atom transfer to an organic fragment.

[1] A. Igau, H. Grützmacher, A. Baceiredo, G. Bertrand, J. Am. Chem. Soc. 1988, 110, 6463; A. Igau, A.

Baceiredo, G. Trinquier, G. Bertrand, Angew. Chem. Int. Ed. Engl. 1989, 28, 621-622. [2] F. Dielmann, O. Back, M. Henry-Ellinger, P. Jerabek, G. Frenking, G. Bertrand, Science (submitted).

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Development of a Single-Component Liquid-Phase Hydrogen Storage Material

Wei Luo, Patrick G. Campbell and Shih-Yuan Liu

(lsy@uoregon.edu)

Department of Chemistry, University of Oregon, Eugene, Oregon 97403, USA

The development of sustainable energy platforms is an important task because of national security, environmental, and financial concerns related to energy supply. New materials for hydrogen storage continue to be attractive toward establishing a carbon-neutral energy infrastructure. The field of chemical hydrogen storage has been dominated by ammonia borane (NH3–BH3, AB) and its derivatives. A potential new hydrogen storage platform based on well-defined carbon(C)-boron(B)-nitrogen(N) heterocyle materials is described. Specifically, I will discuss the development of a liquid-phase hydrogen storage material that is a liquid under ambient conditions, releases H2 controllably and cleanly at 80 °C, and does not undergo a phase change upon H2 desorption. Preliminary investigations into the mechanism of H2 desorption will also be discussed.

[1] Luo, W.; Campbell, P. G.; Zakharov, L. N.; Liu, S.-Y. "A Single-Component Liquid-Phase Hydrogen Storage Material" J. Am. Chem. Soc. 2011, 133, 19326-19329. [2] Luo, W.; Zakharov, L. N.; Liu, S.-Y. "1,2-BN Cyclohexane: Synthesis, Structure, Dynamics, and

Reactivity" J. Am. Chem. Soc. 2011, 133, 13006-13009. [3] Campbell, P. G.; Zakharov, L. N.; Grant, D.; Dixon, D. A.; Liu, S.-Y. "Hydrogen Storage by Boron-

Nitrogen Heterocycles: A Simple Route for Spent Fuel Regeneration" J. Am. Chem. Soc. 2010, 132, 3289-3291.

[4] Staubitz, A.; Robertson, A. P.; Manners, I. “Ammonia-borane and related compounds as dihydrogen sources” Chem. Rev. 2010, 110, 4079-4124.

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Phosphazenes as Scaffolds for the Synthesis of New Molecules by Palladium and Copper Catalyzed Reactions

Cemile Kumas and Patty Wisian-Neilson

(pwisian@smu.edu) Department of Chemistry, Southern Methodist University, Dallas, TX 75275-0414 USA

Both cyclic and polymeric phosphazenes with simple alkyl and aryl substituents attached by direct P-C bonds have been prepared by condensation reactions of N-silylphosphoranimines, Me3SiN=P(X)RR'. Although post-modification of methyl groups in the simple preformed phosphazenes has facilitated the incorporation of a variety of functional groups, variation of the aromatic groups has been more challenging. Several new phosphazenes with more elaborate aryl groups have now been prepared by condensation reactions. In addition, post-modification of the cyclic and polymeric bromophenyl phosphazenes, [NP(C6H4Br)CH3]n, by palladium-catalyzed cross coupling reactions have afforded a series of phosphazenes with wide variety of functional groups attached to the aryl ring by C-C bonds (Suzuki, Sonogashira, and Mizoroki-Heck reactions) and C-N bonds (Buchwald-Hartwig reactions). Synthetic routes to prepare cyclo- and polyphosphazenes with alkyne units attached directly to the P atom, [NP(C≡CR)(C6H6)]n (R = H, SiMe3, C6H5) have also been developed. Post-modification via copper-catalyzed alkyne-azide cycloaddition reactions was used to attach benzyl, anthracene and methoxyethoxyethylene groups. Preliminary studies indicated that thiol-yne and Cadiot-Chodkiewicz alkyne cross-metathesis reactions also have potential utility.

R

N P

CH3

3,n

Br

N P

CH3

3,n

Pd catalyst

N3

+Cu catalyst

PN

C

C

3,n

NN

N

PN3,n

R

R'

R'

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72

Heavier Group 14 Homologues of Carbenes in The Synthesis of Heavier Aromatic and E(0) Compounds

Johanna Flock, Michaela Flock, Amra Suljanovic, Petra Wilfling and Roland C. Fischer

(roland.fischer@tugraz.at) Institute of Inorganic Chemistry, Graz University of Technology

Stremayrgasse 9 V, A-8010 Graz, Austria

The reactions of heavier group 14 homologues of carbenes with various substrates continue to be a key topic in main group chemistry.[1] In this context, we set out to investigate the reaction between sterically encumbered heavier group 14 tetrylenes Ar*2E, (E=Ge, Sn, Pb; Ar*=C6H3-2,6-Mes2) with phosphaalkynes, R-CP. In contrast to E=Sn and Pb, where bis-phosphaalkene substituted stannylenes and plumbylenes where isolated in good to moderate yields, the germylenes provided clean access to the respective germadiphospholes.[2]

Reaction of amino pyridine ligand 1 with E[N(SiMe3)2]2 (E=Ge, Sn, Pb) provided clean access to the heteroleptic tetrylenes 2 and 3 for E=Sn, Pb. In the case of germanium, however, we obtained compound 4 in good yields.[3]

Ultimately, this chemistry enabled us to isolate compounds 5[4] and 6, which are unprecedented examples of mononuclear main group element compounds in which the heavier main group atoms adopts a formal oxidation state of zero.

[1] P. P. Power, Nature, 2010, 463, 171. [2] P. Wilfling, R. C. Fischer manuscript in preparation [3] J.Flock, M. Flock, R. C. Fischer, manuscript in preparation [4] J.Flock, A.Suljanovic, A. Torvisco, W. Schoefberger, M. Flock, R. C. Fischer, submitted

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(-O-Te-N-)4 Macrocycles

Patrick Szydlowski, Phillip J.W. Elder, Joachim Kübel, Chris Gendy, Derek R. Morim, Ignacio Vargas-Baca

(vargas@chemistry.mcmaster.ca) Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West,

Hamilton, Ontario, Canada L8S4M1 Stringing heavy elements in a periodic sequence is key to the design and preparation of new macromolecular materials with unusual properties. In many cases, even when suitable precursors can be synthesized and reaction conditions optimized to promote the formation of long chains, the final result is the formation of small molecules because of the lability of the bonds made by the heaviest elements. For example, Te-N and Te-O combinations most commonly produce four-membered rings. An interesting exception was observed in the structure of 1a,[1] which formally is assembled by the spontaneous concatenation of tellurazole-N-oxide molecules formed in-situ. A second example (1b) of this type of macrocycle was recently characterized.[2] This molecule, however, features a chair conformation in contrast to the twisted boat of 1a. Spectroscopic studies, supported by DFT calculations, were applied to study the dynamic equilibrium between such conformations. The chemistry of these species, including the prospects of an extension to host-guest systems, will be discussed.

[1] J. Kübel, P. J. W. Elder, H. A. Jenkins and I. Vargas-Baca, Dalton Trans, 2010, 39, 11126. [2] P. Szydlowski, Senior Undergraduate Thesis, McMaster University, 2012.

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Macrocyclic Phosphorus(I) Oligomers

Gregory J. Farrar, Erin L. Norton, Bobby D. Ellis and Charles L. B. Macdonald (cmacd@uwindsor.ca)

Department of Chemistry & Biochemistry, University of Windsor, Windsor, Ontario, Canada Over the last decade, we have been investigating the chemistry of compounds containing p-block elements in unusually low oxidation states.[1-2] For group 15, we previously developed convenient syntheses for compounds containing donor-stabilized P(I) ions.[3-5] Most of these compounds are air- and moisture-stable and some are valuable reagents for the synthesis of other stable low-oxidation state species using ligand replacement reactions. Importantly, the amphoteric nature of the P(I) ions makes them ideal main group linkers for the formation of coordination polymers using judiciously-designed ligands (both neutral and anionic). Some of our recent efforts regarding the synthesis and characterization of oligomers/macrocrocycles containing such univalent phosphorus centers, which include the phosphorus-rich analogues of phosphazenes, will be presented.

[1] C. L. B. Macdonald, B. D. Ellis, in Encyclopedia of Inorganic Chemsitry, 2nd ed. (Ed.: R. B.

King), John Wiley & Sons Ltd., 2005. [2] B. D. Ellis, C. L. B. Macdonald, Coord. Chem. Rev. 2007, 251, 936-973. [3] B. D. Ellis, M. Carlesimo, C. L. B. Macdonald, Chem. Commun. 2003, 1946-1947. [4] B. D. Ellis, C. L. B. Macdonald, Inorg. Chem. 2006, 45, 6864-6874. [5] E. L. Norton, K. L. S. Szekely, J. W. Dube, P. G. Bomben, C. L. B. Macdonald, Inorg. Chem.

2008, 47, 1196-1203.

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Novel Stannacyclopentanes – Effective Catalysts or Dead End?

J. Binder, R. Fischer, J. Pichler, B. Seibt, A. Torvisco and F. Uhlig (frank.uhlig@tugraz.at)

Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria

Recently dibutyltindilaureate one of the most popular catalysts for a wide variety of chemical reactions and applications was banned for public use in many countries worldwide. Although this was announced since a couple of year’s attempts to develop a real alternative were only partially successful so fare. Therefore, one of the main research interest of our group is focused currently on the development of novel cyclic, catalytic active species containing the heavy group 14 elements germanium or tin. We discuss here on the synthesis and analytical characterization of a series of 5-membered tin-containing ring systems (A - B) displaying in some cases a surprising reaction behavior. Furthermore a brief introduction about the catalytic activity of such derivatives will be given as well.

Sn Snz z

SnNH

Scheme 1: stannacyclopentanes of type A – C (Z = Me2Si, O)

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Germanium(II),Tin(II) and Lead(II) Amides Containing an Adjacent Coordination Group

Hana Vankatova, Jan Turek, Martin Novotny, Zdenka Padelkova and Ales Ruzicka

(ales.ruzicka@upce.cz) Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of

Pardubice, Studentska 573, Pardubice 532 10, Czech Republic Tetrylenes, low-valent group 14 compounds including carbenes, silylenes, germylenes, stannylenes and plumbylenes, are subject of growing research interest.[1] In particular, metal amides are among the most studied and used compounds in catalysis and new materials preparation.[2] The heavier elements of group 14 metal amides with the metal atom in a lower oxidation state are widely accepted as carbene[3] (M(NR2)), radical[4] (M(NR2)3) or alkyne[5] analogs. Our current interest is focused on the structure and reactivity of different group 14 metal complexes containing [2-(dimethylamino)methyl]aniline which is able to stabilize target compounds as a bidentate ligand by the formation of six-membered diazametallacycle.[6] New results on this field including the formation of higher aggregates (dimers, trimers and tetramers) or clusters will be discussed together with relevant findings in groups of closely related C,N- and O,N-chelated compounds.

Fig. 1: Schematical example of reactivity studied

The authors would like to thank the Grant Agency of the Czech Republic (grant no. P207/12/0223) for the financial support.

[1] For one of recent reviews see: Asay, M.; Jones, C.; Driess, M. Chem. Rev. 2011, 111, 254-296. [2] Lappert, M. F.; Protchenko, A. V.; Power, P. P.; Seeber, A. Metal Amide Chemistry; Chapter 9,

Wiley, John Wiley and Sons, Ltd: Chichester, UK, 2009. [3] (a) Harris, D. H.; Lappert, M. F. J. Chem. Soc., Chem. Commun. 1974, 895-896. (b) Davidson, P. J.;

Harris, D. H.; Lappert, M. F. J. Chem. Soc., Dalton Trans. 1976, 2268-2274. [4] Davidson, P. J.; Hudson, A.; Lappert M. F.; Lednor, P. W. J. Chem. Soc., Chem. Commun. 1973, 21,

829-830. [5] Power, P. P. Nature 2010, 463, 171-177. [6] Vankatova, H; Broeckaert, L; De Proft, F; Olejnik, R; Turek, J; Padelkova, Z; Ruzicka, A, Inorg.

Chem. 2011, 50, 9454-9464.

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Metallo-Organic Clathrates from Self-Assembly of a Five-Fold Symmetric Ligand

Robert J. Less,[a] Thomas C. Wilson,[a] Bihan Guan,[a] Mary McPartlin,[a] Alexander Steiner,[b] Paul T.

Wood and Dominic S. Wright[a] (rjl1003@cam.ac.uk, dsw1000@cam.ac.uk)

[a]Chemistry Department, Cambridge University, Lensfield Rd., Cambridge CB2 1EW, UK [b]Chemistry Department, University of Liverpool, Crown Street, Liverpool L69 3BX, UK

The pentacyanocyclopentadienide anion, Cp(CN)5

- can act as a five-fold symmetric node when coordinated to metal cations. This forces curvature and directs the formation polyhedral cages.

Figure 1. Pentacyanocyclopentadienide anion (1) Figure 2. Cubic-Na[1] showing channels (orange) and voids (yellow). A series of group 1 metal (Na, K, Rb, Cs) complexes with the pentacyanocyclopentadienide anion (1, Figure 1) have been prepared and structurally characterised. Their solid-state structures are highly dependent on the solvent systems used for crystallisation. Crystallisation of Na[1] from nitromethane / diethyl ether results in the formation of Na46{1}48]Na2·(MeNO2)x(Et2O)y (cubic-Na[1], Figure 2), a highly porous metallo-organic framework (MOF) comprising of tetrahedrally close-packed (TCP) arrangements of pentagonal-based dodecahedra (D) and 14-hedra (T) strongly reminiscent of type I gas hydrates 46H2O·6X·2Y (X, Y = CO2, CH4).[1] If, however, Na[1] is crystallised from propan-2-ol / pentane, the resulting MOF formed [Na{1}]45·(H2O)9·(iPrOH)x(C5H12)y is of hexagonal symmetry (hexagonal-Na[1]) and includes 15-hedra (P) in addition to D and T polyhedra. Heavier group 1 metal salts form highly condensed phases with no solvent present when crystallised under the same conditions. Na[1] also provides a valuable starting material with which to access a number of other metal derivatives. Metathesis with metal chlorides allowed the preparation of Co, Cu, Ag and Au complexes of 1.[2] Notably, in these complexes 1 behaves as a -CN donor rather than a -donor, reflecting the electron-withdrawing effect of the C≡N groups on the C5-ring. [1] J. Bacsa, R. J. Less, H. E. Skelton, Z. Soracevic, A. Steiner, T. C. Wilson, P. T. Wood, D. S. Wright,

Angew. Chem. Int. Ed. 2011, 50, 8279-8282. [2] R. J. Less, T. C. Wilson, M. McPartlin, P. T. Wood, D. S. Wright, Chem. Commun. 2011, 47, 10007-

10009; R. J. Less, B. Guan, N. M. Mureson, M. McPartlin, E. Reisner, T. C. Wilson, D. S. Wright, Dalton Trans. 2012, 41, 5919-5924.

1

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Inorganic Rings and Chains via Condensation Reactions of Silylamino, Silylimino, and Silylanilino Derivatives of Phosphorus and Boron

Robert H. Neilson

(R.Neilson@tcu.edu) Department of Chemistry, Texas Christian University, Fort Worth, TX 76129, USA

The chemistry of phosphorus and boron compounds that contain silicon-nitrogen functional groups is both diverse and synthetically useful. The variety of reactions that occur at phosphorus or boron, in combination with facile cleavage of the Si-N bond, makes them potential precursors to many types of acyclic, cyclic, and polymeric P-N and B-N systems. For example, most condensation polymerization routes to phosphazene polymers are based on the high reactivity of Si-N=P compounds known as N-silylphosphoranimines. In a similar vein, we have also been investigating related systems in which the Si-N moiety is attached to a 4-substituted phenyl group as in the title silylanilino derivatives. Some of these systems are being studied as precursors to new types of inorganic ring systems and/or inorganic-organic hybrid polymers. Within this broad context, representative examples of the synthesis and reactivity of precursors of types 1 - 3 will be discussed.

N EMe3Si R

R'

X

N P ORfMe3Si N PR'R

R' R"

Me3Si P

R

R'

N X

2: E = P, BX = Br, SiMe3

3: X = Br, OCH2CF3R, R' = Me, Ph, OCH2CF3

1: R, R', R" = Me, Ph, ORf, CH2SiMe3Rf = CH2CF3

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79

Synthesis and Reactivity of the BN Analog of Ethylcyclobutane, (B-cyclodiborazanyl)amine-borane: Implications for Selective Catalyzed

Dehydrogenation of Ammonia-borane

Hassan Kalviri, Felix Gaertner and R. Tom Baker (rbaker@uottawa.ca)

Department of Chemistry and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON K1N 6N5 Canada

Ammonia-borane (H3N•BH3, AB) has been identified as a promising material for chemical hydrogen storage.[1] Previous work has demonstrated that metal complexes serving as catalysts to release > 2 equiv. of H2 from AB selectively produce the unusual aminoborane trimer, (B-cyclodiborazanyl)amine-borane, 1, the BN analogue of ethylcyclobutane.[2] Both computational[2] and experimental work[3] indicate that 1 arises from the unconventional oligomerization of reactive aminoborane, H2B=NH2, through the intermediacy of the unsymmetrical linear ‘dimer’, H3BNH2BHNH2 that results from the well-known basicity of H on B. After some years of effort, a new synthetic route using the Schwartz reagent, Cp2ZrHCl, and AB affords a 40% yield of 1 and allows for detailed studies of its reactivity and a comparison with its well-known BN cyclohexane isomer, cyclotriborazane, 2.

[1] Stephens, F. H.; Pons, V.; Baker, R. T. Dalton Trans. 2007, 2613; Marder, T. B. Angew. Chem. Int. Ed. 2007, 46, 8116; Hamilton, C. H.; Baker, R. T.; Staubitz, A.; Manners, I. Chem. Soc. Rev. 2009, 38, 279; Staubitz, A.; Robertson, A. P. M.; Manners, I. Chem. Rev. 2010, 110, 4079.

[2] Pons, V.; Baker, R. T.; Szymczak, N. K.; Heldebrant, D. J.; Linehan, J. C.; Matus, M. H.; Grant, D. J.; Dixon, D. A. Chem. Commun. 2008, 6597.

[3] Shaw, W. J.; Linehan, J. C.; Szymczak, N. K.; Heldebrant, D. J.; Yonker, C.; Camaioni, D. M.; Baker, R. T.; Autrey, T. Angew. Chem. Int. Ed. 2008, 47, 7493.

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Exploring the Isoelectronic and Isolobal Analogies in Inorganic Ring Systems

– Studies in Free Radical Chemistry

John J. Hayward and Jeremy M. Rawson (jhayward@uwindsor.ca, jmrawson@uwindsor.ca)

Department of Chemistry & Biochemistry, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada

A variety of 7π-electron inorganic free radicals are known and their physical properties are well documented.[1] The design of new ring systems involves the application of concepts of isomerism, isolobalism and isoelectronicity; the use of alternative p-block elements therefore provides many different options for the construction of new ring systems. The different aspects of the bonding in such systems which have recently been studied by the Rawson group will be presented, particularly with respect to radical stabilisation.

[1] J. M. Rawson , A. Alberola and A. Whalley, J. Mater. Chem., 2006, 16, 2560 – 2575.

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Molecular Heterobimetallic Gallo- and Alumoxanes

Monica Moya-Cabrera§, Ricardo Peyrot, Erandi Bernabé-Pablo and Vojtech Jancik

§

(monica.moya@unam.mx)

Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carr. Toluca-Atlacomulco,

C.P. 50200, Toluca, Estado de México, México. §Academic staff from the Universidad Nacional

Autónoma de México

Alumoxanes are important catalysts and co-catalysts in the polymerization of a broad variety of organic

molecules and their chemistry has been thoroughly under investigation in the last decades.[1]

Nonetheless,

structurally modified alumoxanes remain a synthetic challenge, mainly due to their difficulty to crystallize

in low aggregation and crystalline forms. Indeed, tailor-made alumoxanes, particularly those bearing soft

atoms are unknown to date. Albeit, the presence of both hard and soft donor atoms bound to Al can lead

to a change in the properties of the metal center and thus, to an overall modification of their chemical

behavior. In this regard, we have reported on the preparation of the molecular alumoxane hydroxide and

hydrogen sulfide [{LAl(EH)}2(-O)] ((L = HC[(CMe)N(2,4,6-Me3C6H2)]2–); E = O(1), S(2)) under very

mild conditions.[2]

Herein, we report on the preparation of the unique group 4 and lanthanide heterobimetallic ring systems

derived from 1 and 2, as well as on the molecular galloxane [{LGa(OH)}2(-O)] (3) and its group 4

heterobimetallic complexes (Figure 1). These heterobimetallic systems may be used as model compounds

for structural analyses, elucidation of catalytic mechanisms, as well as precursors in the synthesis of

heterogeneous systems. Furthermore, the presence of two different metals arranged in close proximity can

lead to a cooperative or simultaneous activation of substrate molecules.[3]

Figure 1. Molecular alumoxanes and galloxanes containing Nd and Zr, respectively.

[1] (a) Sinn, H.; Kaminsky, W. Adv. Organomet. Chem. 1980, 18, 99. (b) Feng, T. L.; Gurian, P. L.; Healy,

M. D.; Barron, A. R. Inorg. Chem. 1990, 29, 408. c) Y. Koide, S. G. Bott, A. R. Barron,

Organometallics 1996, 15, 2213. (d) Galimberti, M.; Destro, M.; Fusco, O.; Piemontesi, F.; Camurai,

I. Macromolecules 1999, 32, 258. (e) Kaminsky, W. Catal. Today 2000, 62, 23. (f) Watanabi, M.;

McMahon, C. N.; Harlan, C. J.; Barron, A. R. Organometallics 2001, 20, 460.

[2] González-Gallardo, S. Jancik, V. Cea-Olivares, R. Toscano, R. A. Moya-Cabrera M., Angew. Chem.

Int. Ed. 2007, 46, 2895 – 2898.

[3] Mandal, S. K.; Roesky, H. Acc. Chem. Res. 2010, 43, 248, and references cited therein.

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Electrochemical and Spectroelectrochemical Sharacterization of Redox-active Main Group Compounds: Monomers, Dimers, Rings and Cages

R. T. Boeré

(boere@uleth.ca) Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, AB, Canada

The application of modern electrochemical methods to air- and moisture-sensitive main group compounds provides powerful ways to characterize redox changes and electron transfer reactions. I will discuss the practice and promise of such techniques, including voltammetry (CV, square wave, rotated-disk), electrolysis, UV-visible spectroelectrochemistry and simultaneous electrochemistry electron paramagnetic resonance (SEEPR) spectroscopy. The application of such methods to a variety of main group compounds will feature, by way of illustration, monomers, dimers, rings and cage compounds of elements drawn largely from Groups 15 and 16. [1] R. T. Boeré, T. L. Roemmele and X. Yu, Inorg. Chem., 2011, 50, 5123-5136. [2] R. T. Boer , T. Chivers, T. L. Roemmele and H. M. Tuononen, Inorg. Chem., 2009, 48, 7294-7306. [3] T. L. Roemmele, J. Konu, R. T. Boer and T. Chivers, Inorg. Chem., 2009, 48, 9454-9462. [4] R. T. Boeré, A. M. Bond, T. Chivers, S. W. Feldberg and T. L. Roemmele, Inorg. Chem., 2007, 46,

5596-5607. [5] R. T. Boeré, A. M. Bond, S. Cronin, N. W. Duffy, P. Hazendonk, J. D. Masuda, K. Pollard, T. L.

Roemmele, P. Tran and Y. Zhang, New. J. Chem., 2008, 32, 214.

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Nanometric Molecular Heterometallic Silicates

Vojtech Jancik,* Miguel A. Velázquez-Carmona, Libia González-Mirelles, Eduardo Herappe-Mejía, Raúl Huerta-Lavorie, Diego Solis-Ibarra, Marisol Reyes-Lezama, Nieves Zavala-Segovia

(vjancik@unam.mx) Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carr. Toluca Atlacomulco km.

14.5, C.P. 50200, Toluca, Estado de México, México. *Academic staff from the Universidad Nacional Autónoma de México

An important component of the earth’s crust are multimetallic silicates and alumosilicates, which is reflected in its elemental composition (46.6% O, 27.8% Si, 8.1% Al). Many of these minerals belong to the family of zeolites and contain different tridimensional connectivity and arrangements, which often result in the formation of infinite channels in the structure. The preparation of materials of this nature, which contain silicon and one or more different metals directly incorporated in the inorganic framework is still a challenge, mainly due to the lack of control over their distribution. Thus, it is desirable to have a single source precursors with all necessary metal atoms already connected to silicate moieties. Herein, we report on molecular heterobimetallic alumo- and gallosilicates with group 4 or lanthanide metals with inorganic cores of 0.8 – 1.3 nm. Figure 1 presents one example of such alumotitanosilicate with 3R and 4R rings connected in a spiro fashion, based on molecular precursors reported recently by our group.[1]

Figure 1. Molecular structure of an aluminotitanosilicate with thermal ellipsoids at 50 % probability only for noncarbon atoms. Hydrogen atoms have been omitted for clarity. [1] a) F. Rascón-Cruz, R. Huerta-Lavorie, V. Jancik, R. A. Toscano, R. Cea-Olivares, Dalton Trans.

2009, 1195–1200. b) V. Jancik, F. Rascón-Cruz, R. A. Toscano, R. Cea-Olivares, Chem. Commun. 2007, 4528–4530. c) R. Huerta-Lavorie, F. Rascón-Cruz, D. Solis-Ibarra, N. Zavala-Segovia, V. Jancik, Eur. J. Inorg. Chem. 2011, 4795–4799. d) D. Solis-Ibarra, M. de J. Velasquez-Hernandez, R. Huerta-Lavorie, V. Jancik, Inorg. Chem. 2011, 50, 8907–8917. e) M. A. Velásquez-Carmona, Libia González-Mireles, Vojtech Jancik, manuscript en preparation. f) R. Huerta-Lavorie, D, V. Báez-Rodríguez, V. Jancik, manuscript en preparation.

Oral 50

IRIS-13 Victoria

84

Oxidation of Heterocyclic Phosphenium Cations

Arthur D. Hendsbee, Nick A. Giffin and Jason D. Masuda (Jason.masuda@smu.ca)

The Maritimes Centre for Green Chemistry and the Department of Chemistry, Saint Mary's University, Halifax, Nova Scotia, B3H 3C3, Canada

In the continuing research of low valent and low oxidation state carbon and phosphorus centers, our research group has recently focused on the chemistry of cationic heterocyclic phosphorus systems. Our developments in the reactivity of heterocyclic phosphenium cations with terminal O-N compounds and various heterocycles has proven to be fruitful. 1. We have explored the reactivity of these systems with N-oxides. In particular, we have isolated a series of Lewis base stabilized oxophosphonium (aka phosphacylium) cations that have terminal P=O fragments. 2. We also see oxygen abstraction from the stable radical TEMPO ((2,2,6,6-Tetramethylpiperidin-1-yl)oxyl). The possible formation of a transient nitrenium cation will be discussed

Oral 51

IRIS-13 Victoria

85

Stabilization by O,C,O-Coordinating Pincer-Type Ligands: From Tin(IV) to Sn(0)? Low-valent Organotin Compounds and their Transition Metal

Complexes

Klaus Jurkschat (klaus.jurkschat@tu-dortmund.de)

Lehrstuhl für Anorganische Chemie II der Technischen Universität, Otto-Hahn-Str. 6, 44227 Dortmund, Germany

The syntheses, characterization by state-of-the-art analytical methods, and evaluation by DFT calculations of the bonding situations of the compounds A – K is reported. Of particular interest are the organotin(I) compounds of types C and D, and the unprecedented platinum complexes H – K.

[1] a) V. Deáky, M. Schürmann, K. Jurkschat, Z. Anorg. Allg. Chem., 2009, 635, 1380; (b) M. Henn, V.

Deáky, S. Krabbe, M. Schürmann, M. H. Prosenc, S. Herres-Pawlis, B. Mahieu, K. Jurkschat, Z. Anorg. Allg. Chem., 2011, 637, 211; (c) M. Wagner, K. Dorogov, M. Schürmann, K. Jurkschat, Dalton Trans., 2011, 40, 8839; (d) M. Wagner, C. Dietz, S. Krabbe, S. G. Koller, C. Strohmann, K. Jurkschat, Inorg. Chem., 2012, DOI: 10.1021/ic3005954.

Oral 52

IRIS-13 Victoria

86

Revisiting a Highly Unusual Phosphine: Structure and Reactivity of P7H3

Hongsui Sun,a Javier Borau-Garcia,a Gary D. Enrightb and Roland Roeslera

(roesler@ucalgary.ca) Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4

Canada, and Steacie Institute for Molecular Sciences, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6, Canada

P7H3 is a highly unusual phosphine that was described by Baudler more than three decades ago. It is a yellow crystalline solid that resembles sulfur in appearance, it is air stable and lacks the typical phosphines smell, and it does not sublime or melt without decomposition. It proved insoluble in all 15 solvents tested by the authors, including P2H4 and molten white phosphorus.[1] A solution 31P NMR spectrum conducted on freshly prepared P7H3 before its precipitation from solution confirmed the presence of two diastereoisomers featuring the same bicyclic framework.[2] This was in good agreement with the synthesis of P7H3 via hydrolysis of P7(SiMe3)3, however, it did not account for its chemical and physical properties. Assuming that the unusual properties of P7H3 would be due to either strong intermolecular interactions or polymerization, leading to the formation of a very stable crystal lattice, we set to determine the solid state structure of this material using diffraction techniques, as well as mass spectrometry. The results of these studies, as well as the reactivity of P7H3 towards N-heterocyclic carbenes, will be presented.

Figure

[1] M. Baudler, H. Ternberger, W. Faber, J. Hahn, Z. Naturforsch. 1979, 34B, 1690-1697. [2] M. Baudler, R. Riekenhof-Böhmer, Z. Naturforsch. 1985, 40B, 1424-1429.

Oral 53

IRIS-13 Victoria

87

Synthesis of Functionalized Bicyclo[222]octasilanes

B. Hasken and H. Stüger (bernd.hasken@tugraz.at)

Institute for Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz There exists pronounced evidence, that electronic coupling of donor and acceptor substituent groups via rigid oligosilane bridges can be a rather effective process.[1] In this context the present paper describes novel preparative approaches to dipolar oligosilane model substances with donor and acceptor moieties connected by the dodecamethylbicyclo-[2.2.2]-octasilane framework (1), which has been successfully prepared and functionalized just recently by Marschner et al. in a pioneering study.[2] Our initial results, however, quickly revealed that the rigid structure of 1 apparently prevent successful nucleophilic substitution reactions at the brominated bridgehead silicon atoms from 3. 1, however, can be successfully functionalized when the polarity of the precursors is reversed.

Scheme 1: Functionalization of a bicyclo[222]octasilane.

A totally different approach is to synthesize already functionalized bycyclo[222]octasilane cages as shown in scheme 2.[3]

Scheme 2: Synthesis of a phenylated bicyclo[222]octasilane. [1] H. Tsuji, J. Michl, K. Tamao, J. Organomet. Chem.685 (2003) 9 [2] R. Fischer, T. Konopa, S. Ully, J. Baumgartner, C. Marschner, J. Organomet. Chem.685 (2003) 79 [3] C. Krempner, U. Jäger-Fiedler, C. Mamat, A. Spannenberg, K. Weichert New J. Chem., 29 (2005)

1581

Oral 54

IRIS-13 Victoria

88

Merging the Chemistry of Electron-Rich Olefins (ERO) with Imidazolium Ionic Liquids

Cody N. Sherren,a Changhua Mu,b Michael I. Webb,b Iain McKenzie,b Brett M. McCollum,b Jean-Claude

Brodovitch,b Paul W. Percival,b Tim Storr,b Kenneth R. Seddon,c Jason A. C. Clyburnea and Charles J. Walsbyb

(Jason.Clyburne@smu.ca) a Maritimes Centre for Green Chemistry, Department of Chemistry, Saint Mary’s University, Halifax, NS,

B3H 3C3, Canada, b Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada

c School of Chemistry and Chemical Engineering, Queen’s University, Belfast, BT7 1NN, Northern Ireland, UK

Ionic liquids (ILs) have attracted attention because of their potential applications in various industrial settings. This report will survey some chemistry of simple molecular species with structurally simple reagents in ionic media. The chemistry of N-heterocyclic carbenes is intimately associated with chemistry observed in imidazolium based ionic liquids. Likewise, the chemistry of Electron-Rich Olefins (ERO) was important in the early understanding of NHCs, and EROs possess chemistry that is unique among alkenes. The link and relevance of EROs and IL chemistry has been ignored even though there is some evidence indicating its role. Here we report that the ionic liquid 1-ethyl-3-methylimidazolium tetrachloroaluminate(III) reacts with lithium to produce a persistent radical, which can be considered a hydrogen-atom adduct of an electron-rich olefin (ERO). Reaction of tetrakis(dimethylamino)ethene, a bona fide ERO, with muonium, produces a structurally similar radical. These results demonstrate the importance of ERO chemistry to applications of ionic liquids, particularly where charge carrying in basic conditions is important, such as in photocells.

Poster 1

IRIS-13 Victoria

89

Synthesis, Reactivity and Ring-opening Polymerization (ROP) of [V(5-C5H4)(7-C7H6)SntBu2]

Klaus Dück and Holger Braunschweig

(klaus.dueck@uni-wuerzburg.de) Institute of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074

Würzburg, Germany During the last decades the interest in poly(metallocenes) considerably increased, because these materials have proven their suitability in technical applications, such as nanotechnologies or metal-based ceramics.[13] Due to the weakness of the bond between the ipso-carbon and the tin-atom, tin-bridged ansa-complexes are attractive for ROP reactions.[4]

The first tin-bridged [1]trovacenophane, [V(5-C5H4)(7-C7H6)SntBu2] (2), is synthesized by salt-elimination reaction between [V(5-C5H4Li)(7-C7H6Li)]pmdta (1) and Cl2SntBu2. The purple crystalline solid is isolated in moderate yields and characterized by common spectroscopic methods, which confirm the strained nature of the molecule. The treatment of [V(5-C5H4)(7-C7H6)SntBu2] with [Pt(PEt3)3] affords the platinastanna[2]trovacenophane 3, whereupon the Pt(0)-fragment exclusively inserts into the bond between the ipso-Carbon of the C7H6-ring and the bridging tin-atom. Ring-opening polymerization reaction of [V(5-C5H4)(7-C7H6)SntBu2] was performed in the presence of Karstedt catalyst, yielding the corresponding poly(trovacenylstannan) 4.

[1] Arsenault, A. C.; Miguez, H.; Kitaev, V.; Ozin, G.A.; Manners, I.; Adv. Mater. 2003, 15, 503. [2] Rehahn, M.; Bellas, V.; Angew. Chem., 2007, 119, 5174; Angew. Chem. Int. Ed. 2007, 46, 5082. [3] Adams, J. A.; Braunschweig, H.; Fuß, M.; Kraft, K.; Kupfer, T.; Manners, I.; Radacki, K.; Whittel,

G. R.; Chem. Eur. J. 2011, 17, 10379. [4] Elschenbroich, C.; Organometallchemie 2008, 6. überarbeitete Auflage, Teubner Verlag / GWV

Fachverlage GmbH, Wiesbaden.

Poster 2

IRIS-13 Victoria

90

Probing the Effect of Base-stabilization in Boryl and Borylene Complexes

Holger Braunschweig and Thomas Kramer (thomas.kramer@uni-wuerzburg.de)

Institute of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074 Würzburg, Germany

Fundamental studies on transition metal complexes containing well-defined two-electron-two-centre M–B bonds have become an area of great interest due to the appearance of boryl complexes as key intermediates in a range of catalytic reactions and their remarkably strong σ-donation abilities. The extent of π-backdonation in these complexes was first determined by occupying the vacant p orbital of an iron dihaloboryl complex by a Lewis base, and the resulting changes in the MB bond distance were compared to the parent compound (see following scheme).[1-3]

The reaction of the base-stabilized dichloroboryl complex with a halide abstracting reagent provided access to the first cationic base-stabilized chloroborylene complex analogous to literature-reported base-stabilized aminoborylene complexes of Aldridge. Though these compounds are formally borylene species, a trigonal planar coordination at the boron atom is observed, similar to boryl complexes.[4]

Abstraction of the Lewis base leading to the first cationic chloroborylene complex is a future goal of this project.

[1] G. J. Irvine, M. J. G. Lesley, T. B. Marder, N. C. Norman, C. R. Rice, E. G. Robins, W. R. Roper, G.

R. Whittell, L. J. Wright, Chem. Rev. 1998, 98, 2685–2722. [2] H. Braunschweig, R. D. Dewhurst, A. Schneider Chem. Rev. 2010, 110, 3924–3957. [3] H. Braunschweig, K. Radacki, F. Seeler, G. R. Whittell, Organometallics 2006, 25, 4605–4610. [4] S. Aldridge, C. Jones, T. Gans-Eichler, A. Stasch, D. L. Kays (nee Coombs), N. D. Coombs, D. J.

Willock, Angew. Chem. Int. Ed. 2006, 118, 6264–6268.

Poster 3

IRIS-13 Victoria

91

Metalloborylene Complexes Showing a Wide Range of Reactivity

Holger Braunschweig and Katharina Ferkinghoff (katharina.ferkinghoff@uni-wuerzburg.de)

Institute of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074 Würzburg, Germany

The highly reactive borylene base-free ligand BR, only stabilized in the coordination sphere of transition metal fragments, established the class of bridged[1] and terminal[2] borylene complexes. These compounds do not only show an amazing thermodynamic stability, but also a widespread pattern of reactivity. For instance, the terminal ferroborylene unit of [{(η5-C5Me5)Fe(CO)2)} (µ2-B){Cr(CO)5}] (1) can either be transferred to an alkyne fragment to form ferroborirenes 2-5,[3] or via intermetallic borylene transfer to further metal fragments to obtain so far unknown terminal metalloborylenes 6.

Adding the transition metal base [Pt(PCy3)2] to 6 results in the formation of [{(η5-C5Me5) (CO)2Fe}(µ-B)(µ-H){CpW(CO)2}], showing an exceptional T-shaped coordination mode. Hence, this compound is best to be described as a metal-base stabilized metalloborylene.

[1] P. Bissinger, H. Braunschweig, F. Seeler; Organometallics 2007, 26, 4700. H. Braunschweig,

C. Kollann, K. W. Klinkhammer; Eur. J. Inorg. Chem. 1999, 9, 1523. [2] H. Braunschweig, K. Radacki, D. Scheschkewitz, G. R. Whittell; Angew. Chem. Int. Ed. 2005, 44,

1658. [3] H. Braunschweig, I. Fernández, G. Frenking, K. Radacki, F. Seeler; Angew. Chem. 2007, 119, 5307.

Poster 4

IRIS-13 Victoria

92

Synthesis and Reactivity of Platinum Oxoboryl and Platinum Alkylideneboryl Complexes

Johannes Brand, Holger Braunschweig, Krzysztof Radacki and Achim Schneider

(johannes.brand@uni-wuerzburg.de) Institute of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074

Würzburg, Germany Until recently monomeric oxoboranes have been detected only as short-lived species in gas-phase[1] or low-temperature matrix experiments.[2] The reaction of Br2BOSiMe3 with [Pt(PCy3)2] yielded the oxoboryl complex trans-[(Cy3P)2BrPt(B≡O)] via oxidative addition of a BBr bond and spontaneous elimination of BrSiMe3.

[3]

Evidence for the remarkable stability of the oxoboryl ligand is demonstrated by its reaction with [Bu4N]SPh. The nucleophile does not react with the BO moiety but instead substitutes the ligand trans to the BO.[3] In contrast, abstraction of the bromide ligand with Ag[Al(pftb)4] (pftb = perfluoro-tert-butoxy) induces instant cyclodimerization of the oxoboryl complex.[4] With Ag[BArf

4] (Arf = 3,5-bis(trifluoromethyl)phenyl) and an excess of acetonitrile the cationic complex trans-[(Cy3P)2(MeCN)Pt(B≡O)][BArf

4] could be obtained.[5] With B(C6F5)3 the oxoboryl complex yielded the Lewis acid-base adduct trans-[(Cy3P)2BrPt{B≡O B(C6F5)3}].[5] Recently a 1,2-dipolar addition of Me3SiNCS to the oxoboryl moiety was also observed.[6] Analogously to the synthesis of the oxoboryl complex the reaction of Br2BCH(SiMe3)2 with [Pt(PCy3)2] yielded the first platinum alkylideneboryl complex trans-[(Cy3P)2BrPt{B=C(H)SiMe3}].[6] In this complex the bromide ligand could be substituted with a methyl group by the reaction with methyllithium to obtain trans-[(Cy3P)2MePt{B=C(H)SiMe3}]. Additionally the synthesis of the boryl complex trans-

[(Cy3P)2BrPt{B(Br)CH2SiMe3}] could be carried out via oxidative addition of one BBr2BCH2SiMe3 to [Pt(PCy3)2]. However due to the lack of steric demand, no elimination of bromosilane was observed.

[1] H. F. Bettinger, Organometallics 2007, 26, 6263–6267. [2] L. Andrews, T. R. Burkholder, J. Phys. Chem. 1991, 95, 8554–8560. [3] H. Braunschweig, K. Radacki, A. Schneider, Science 2010, 328, 345-347. [4] H. Braunschweig, K. Radacki, A. Schneider, Angew. Chem. Int. Ed. 2010, 49, 5993-5996. [5] H. Braunschweig, K. Radacki, A. Schneider, Chem. Commun. 2010, 46, 6473-6475. [6] J. Brand, Diploma thesis 2010, Julius-Maximilians-University Würzburg.

Poster 5

IRIS-13 Victoria

93

Novel Reactivity of Terminal Borylene Complex [Cp(CO)2Mn=B-tBu]

Rong Shang, Holger Braunschweig and Krzysztof Radack (rong.shang@uni-wuerzburg.de)

Institute of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074 Würzburg, Germany

It has been shown that the reaction of the terminal borylene complex [Cp(CO)2 tBu] (1) with platinum and palladium(0) complexes [M’(PCy3)2] (M’ = Pt, Pd) results in formation of heterodinuclear complexes [Cp(CO)Mn(μ-CO){μ-B(tBu)}M’(PCy3)2],[1] in a similar fashion to those reported for the Group 6 metal borylene complexes [(OC)5M=BN(SiMe3)2] (M = Cr, W).[2] Furthermore, complex 1 undergoes metathesis reactions with polarized unsaturated substrates, such as benzophenone, to form exotic manganese carbene complexes via a [2+2] cycloaddition/cycloreversion mechanism.[3]

Recent studies revealed vastly different behavior of 1 with seemingly similar substrates. The reaction with [AuClL] (L = PCy3, PPh3, ITol, ITol = [Tol-NCH]2C:) results in formation of heterodinuclear complexes [Cp(CO)2Mn(AuL){B(tBu)(Cl)}] (2), which are best viewed as products of 1,2-addition of the AuCl bond across the Mn=B bond. Furthermore, addition of two equivalents of super mesityl isonitrile (CNMes*, Mes* = 2,4,6-tri(tert)butylphenyl) to 1 induces coupling between its borylene moiety and the carbonyl ligands to form complex 3, which features a 11B NMR shift of 57 ppm. Upon treatment with a strong Lewis acid, complex 3 converts back to the terminal borylene complex 1 quantitatively. Also, treatment of 2 with two equivalents of CNMes* results in loss of of AuClL and formation of 3.

[1] H. Braunschweig, M. Burzler, T. Kupfer, K. Radacki and F. Seeler, Angew. Chem. Int. Ed. 2007, 46,

7785–7787. [2] (a) H. Braunschweig, D. Rais and K. Uttinger, Angew. Chem. Int. Ed. 2005, 44, 3763-3766.

(b) H. Braunschweig, K. Radacki, D. Rais and K. Uttinger, Organometallics 2006, 25, 5159-5164. [3] H. Braunschweig, M. Burzler, T. Kupfer, K. Radacki and F. Seeler, Angew. Chem. Int. Ed. 2007, 46,

8071-8073.

Poster 6

IRIS-13 Victoria

94

Stable Radicals from -Conjugated Boroles

Holger Braunschweig and Christian Hörl (christian.hoerl@uni-wuerzburg.de)

Institut of Inorganic Chemistry, Julius-Maximilians-Universität Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany

Owing to their isoelectronic relationship to neutral methyl radicals, stable boron-radicals anions [BR3]• ˉ have attracted considerable attention. The most prominent representative is the trimesitylborane radical anion which has been investigated since the 1950s and characterized as a fairly stable species.[1] Stable boron diradicals have been studied to a lesser extent and only a few examples have been reported.[2, 3] Boroles are known for their strong electron deficiency and their antiaromaticity due to the 4 electron system.[4] In addition, boroles exhibit interesting spectroscopic properties which arise from the small HOMO-LUMO gap. Our group showed recently, that a stepwise reduction of boroles to their dianions is possible. Even the isolation of an unusual borole radical anion, bearing 5 electrons, was successful.[5] Starting from the thiophene bridged bisborole 1 we were able to isolate a stable borole-based diradical dianion 2. Herein we wish to present the structure and properties of the diradical 2.

[1] H. C. Brown, V. H. Dodson, J. Am. Chem. Soc. 1957, 79, 2302. [2] D. Scheschkewitz, H. Amii, H. Gornitzka, W. W. Schoeller, D. Bourissou, G. Bertrand, Science 2002,

295, 1880. [3] A. Racja, S. Racja, S. R. Desai, J. Am. Chem. Soc. 1995, 1957. [4] H. Braunschweig, T. Kupfer, Chem. Comm. 2011, 47, 10903. [5] H. Braunschweig, V. Dyakonov, J. O. C. Jimenez-Halla, K. Kraft, I. Krummenacher, K. Radacki, A.

Sperlich, J. Wahler, Angew. Chem. Int. Ed. 2012, 51, 2977.

Poster 7

IRIS-13 Victoria

95

Benzothiophene-Based Palladacycles and SCN Pincer-Type Palladacyles: Synthesis, Characterization and Applications in C-C Coupling Reactions

Pravin R. Likhar (plikhar@iict.res.in)

Organometallic Chemistry Gp., I&PC Division, CSIR-Indian Institute of Chemical Technology, Uppal Road Tarnaka, Hyderabad-500607 India

An intramolecular thiopalladation has been achieved by the treatment of o-SMeC6H4C≡CC(CF3)(=N-4-OCH3C6H4) with Li2PdCl4/LiCl in methanol at 0°C to afford [(C8H4S-3-)C(CF3)(=N-4-OCH3C6H4)Pd(μ-Cl)]2 and o-SMeC6H4C=CClC(CF3)(=N-4-OCH3C6H4)PdCl (1).[1] The synthetic strategy was also extended to preparation of benzoselenophene-based dimeric palladacycles. On the other hand, a selective synthesis of SCN pincer palladium complex has been achieved from bis(o-SMe)2C6H3C≡CC(CF3)(=N-4-OCH3C6H4) with PdCl2(PhCN)2 in THF at 0°C (2)[2] (Scheme 1). The dimeric benzothiophene-based palladacycles were treated with an excess of phosphine ligands in benzene at room temperature to afford selectively trans-bis(phosphine) palladium complexes in good yields. The trans-bis(tricyclohexylphosphine) palladium complex was found to be an active catalyst in the Suzuki coupling of electron rich aryl chlorides. The complex was also employed in the catalytic synthesis of sterically hindered biaryls (Scheme 2).[3] Further, a method for stoichiometric functionalization of benzothiophene was developed by Heck type-coupling of alkenes and intramolecularly generated benzothiophene-based palladacycle. The synthetic strategy of structurally diversed 3-alkenylbenzo[b]thiophene was extended to the preparation of 3-alkenylbenzo[b]selenophenes (Scheme 2).[4]

XMeRf

NAr

X

NAr

Rf

Pd

Cl

MeX Pd

ClRf

NAr

Li2PdCl4/LiClMeOH, 0°C

Rf = CF3, C4F9

Major

2

X= S, Se

SMeCF3

NArSMe

+

Ar = C6H5; o-OMe-C6H4; p-OMe-C6H4

(1)

S

NArPdMeS

Cl

CF3

PdCl2(PhCN)2

THF 0 ºC(2)

Cl Trace

SMeRf

NAr

S

NAr

Rf

PdCl

MeS Pd

ClRf

NArLi2PdCl4/LiCl

MeOH, 0°C

S

NAr

Rf

PdR3P PR3

Cl

PR3Benzene

RT

S

NHAr

Rf

EWG

EWG

Oxidant, THF, 70°C1.

2. Reduction

Pd sal t,

EWG

Oxidant,

THF, 70°C

1.

2.Redu

ction

R1 = p-OMe, HRf = CF3, C4F9

R1 = H, Cl, FRf = CF3, C2F5, C4F9

R = Ph, CyR1 = p-OMeRf = CF3

(1) (2) (3)

(4)

(5)

X

OMe

B(OH)2

MeO( 4)

X = Cl, Br

2

Heck-type Coupling

Suzuki Coupling

Thiopalladation

[1] P. R. Likhar, S. M. Salian, S. Roy, M. L. Kantam, B. Sridhar, K. V. Mohan and B. Jagadeesh

Organometallics, 28, 3966-3969 (2009). [2] S. S. Racharlawar, M. Salian Subhas and P. R. Likhar (Communicated, 2012) [3] M. S. Subhas, S. S. Racharlawar, B. Sridhar, P. K. Kennady, P. R. Likhar, M. L. Kantam and S.

K. Bhargava, Organic & Biomolecular Chemistry, 8, 3001-3006 (2010). [4] M. Karkhelikar, S. S. Racharlawar, M. S. Subhas and P. R. Likhar, J. Organomet. Chem. in press.

Poster 8

IRIS-13 Victoria

96

Formation and Reactivity of Intramolecular Ti-C Bond in Substituted Titanocene Derivatives

Michal Horáček and Karel Mach (michal.horacek@jh-inst.cas.cz)

J. Heyrovský Institute of Physical Chemistry of Academy of Sciences of the Czech Republic,v.v.i., Dolejškova 2155/3, 182 23, Prague 8, Czech Republic

The paramagnetic singly tucked-in permethyltitanocene [Ti(III){η5:η1-C5Me4(CH2)}(η5-C5Me5)] (1) was first observed when an equilibrium mixture of decamethyltitanocene [Ti(η5-C5Me5)2] with its singly tucked-in hydride [TiH{η6-C5Me4(CH2)}(η5-C5Me5)] was sublimed under vacuum.[1] Later on, thermolysis of the decamethyltitanocene monoalkyl compounds [Ti(III)R(η5-C5Me5)2] (R = Me, Et, Pr, CH2CMe3) appeared to be another clean and convenient method for obtaining 1.[2] This contribution reports on the formation of intramolecular Ti-C bond in variously substituted titanocene derivatives and reactivity of the singly tucked-in permethyltitanocene 1 towards the series of various molecules. Particularly, the protolysis with hydrogen sulphide, silanols or alcohols opened an access to new titanocene sulphide compounds [3] or permethyltitanocene silanolates and alcoholates [4], respectively. [1] J. E Bercaw, J. Am. Chem. Soc. 1974, 96, 5087. [2] G. A Luinstra, J. H Teuben, J. Am. Chem. Soc. 1992, 114, 3361. [3] J. Pinkas, I. Císařová, M. Horáček, J. Kubišta, K. Mach, Organometallics 2011, 30, 1034. [4] V. Varga, I. Císařová, R. Gyepes, M. Horáček, J. Kubišta, K. Mach, Organometallics 2009, 8(6),

1748. M. Horáček, R. Gyepes, I. Císařová, J. Kubišta, J. Pinkas, K. Mach, J. Organomet. Chem. 2010, 695, 2338. R. Gyepes, V. Varga, M. Horáček, J. Kubišta, J. Pinkas, K. Mach, Organometallics 2010, 29, 3780.

Poster 9

IRIS-13 Victoria

97

Catalytic Trimerisation of Bissilylated Diazomethane and Aminoisonitrile

Alexander Villinger,a Muhammad Ibad,a Peter Langer,a,b Fabian Reißa and Axel Schulza,b (alexander.villinger@uni-rostock.de)

a Department of Chemistry, University of Rostock, Albert-Einstein Str. 3a, D-18059 Rostock, Germany; b

Leibniz Institute for Catalysis at the University of Rostock, Albert-Einstein Str. 29a, D-18059 Rostock, Germany

The silylium ion [Me3Si]+ might be regarded as a sterically demanding big proton, and, similar to a proton, the bulky silylium ion is always solvated forming the [Me3Si(solv.)]+ ion.[1] Only recently, the full series of salts containing the bissilylated halonium/pseudohalonium cations [Me3Si–X–SiMe3]+ (X = F, Cl, Br, and I; CN, N3, OCN, SCN) were generated and fully characterized using the super Lewis acidic silylating media Me3Si–X and [Me3Si(solv.)]+ salt.[2] In view of the success of the pseudohalogen concept in super Lewis acidic silylating media, we were intrigued by the idea to utilize the enormous Lewis acidity of the [Me3Si]+ ion, to activate small molecules, such as bissilylated diazomethane (Me3Si)2CNN, which can be considered as a pseudochalkogen. In the present study, the three constitutional isomers with a NNC unit, (Me3Si)2CNN, (Me3Si)2NNC and (Me3Si)NCN(SiMe3) were reacted with [Me3Si(solv.)][B(C6F5)4] (solv. = HSiMe3, toluene) to afford the silylated pseudochalkogen salts. However, while the aminonitrilium cation [Me3SiNCN(SiMe3)2]+ was obtained as colourless crystals, a more complex reaction was observed for the diazomethane and aminoisonitrile derivates, finally yielding the silylated 4-diazenyl-3-hydrazinyl-1H-pyrazole (1) which can be considered the formal trimerization product (Figure 1). Nevertheless, in both reactions, the [Me3SiCNN(SiMe3)2]+ salt (2) could be identified as catalyst which crystallized out at the end of the reactions and indicated an isomerization of diazomethane to aminoisonitrile. The catalytic process can be carried out with catalyst concentrations less than 1 mole% and is completely selective.

Figure 1. ORTEP drawing of the molecular structure of 1 and 2 in the crystal.

[1] J. B. Lambert, S. Zhang, S. M. Ciro, Organomet. 1994, 13, 2430–2443; b) J. B. Lambert, S. Zhang, J. Chem. Soc., Chem. Commun. 1993, 383–384; C. A. Reed, Z. Xie, R. Bau, A. Benesi, Science 1993, 262, 402–404.

[2] M. Lehmann, A. Schulz, and A. Villinger, Angew. Chem. Int. Ed., 2009, 48, 7444–7447; A. Schulz, A. Villinger, Chemistry – Eur. J. 2010, 16, 7276–7281.

Poster 10

IRIS-13 Victoria

98

Metallation of Cyclotetrasilyldiphosphin with Earthalkaline Silazanides

Michael Feierabend and Carsten von Hänisch (michael.feierabend@chemie.uni-marburg.de)

Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4 35032 Marburg, Germany

In recent studies, we were able to synthesise the branched oligosilan tris(di-isopropyl-chloro-silyl)phenylsilan 1. In a reaction of 1 with [Li(DME)PH2], the cyclic tetrasilyldiphospin 2 can be isolated, which is the result of a rearrangement of one of the di-isopropyl-silyl-groups. In this poster, we present the synthesis and characterization of 1 and 2 as well as the metallation of compound 2 with alkaline earth metal silazanides. The product of these reactions were characterised by multi nuclear NMR spectroscopy and single crystal X-ray structure analysis. They show a different degree of oligomerization depending on the metal used.

SiSiiPr2

SiiPr2

SiiPr2

ClCl

Cl

[Li(DME)PH2]SiH

SiPH

Si

SiPH

iPr2 iPr2

iPr2

M{N(SiMe3)2}2

1 2

M = alkaline earth metal

Poster 11

IRIS-13 Victoria

99

Synthesis and Coordination Chemistry of Cagelike Siloxane Compounds of Elements of the 15th Group

Christian Bimbös and Carsten von Hänisch

(Bimboes@students.uni-marburg.de) Fachbereich Chemie, Philipps-Universität Marburg, Hans Meerwein-Straße 4, 35032 Marburg, Germany Recently, we reported the synthesis of the cage like compound P2[{SiMe2}2O]3 and its coordination properties. Further investigations on the coordination within the cage compound showed a dimerisation to the larger compound P4[{SiMe2}2O]6 after treating with the lithium salt of the weakly coordinating anion Li[Al{OC(CF3)3}4].[1] On this poster, we report about the synthesis of the analogous arsenic and stibane compounds E2[{SiMe2}2O]3 (with E = As, Sb). The arsenic cage compound 1 was obtained by the reaction of Li[(dme)AsH2] with the dichlorodisiloxane (ClSiMe2)2O. We were able to obtain the complex 2 by the reaction of the arsenic cage compound As2[{SiMe2}2O]3 with a strong lewis acid AlEt3. On treating the arsenic cage compound As2[{SiMe2}2O]3 (1) with the lithium salt of the weakly coordinating anion Li[Al{OC(CF3)3}4], a dimerisation reaction to As4[{SiMe2}2O]6 (3) was observed similar to the corresponding phosphoric compound. Further it was possible to obtain the analogous Sb cage compound Sb2[{SiMe2}2O]3 (3) by the reaction of Na3Sb with the dichlorodisiloxane (ClSiMe2)2O.

AsMe2Si

O

Me2Si As

Me2SiO

SiMe2

As SiMe2

O

SiMe2As

SiMe2 OSiMe2

Me2Si

O

Me2Si

SiMe2

OSiMe2

As AsSiMe2 SiMe2

SiMe2 SiMe2O

O

OMe2Si SiMe2

6 [Li(dme)AsH2] + 3 O(SiMe2Cl)2 - 4 AsH3- 6 LiCl

1. Li[Al{OC(CF3)3}4]2. THF

Sb SbSiMe2 SiMe2

SiMe2 SiMe2O

O

OMe2Si SiMe2

2 Na3Sb + 3 O(SiMe2Cl)2- 6 NaCl

As AsSiMe2 SiMe2

SiMe2 SiMe2O

O

OMe2Si SiMe2

AlEt3Et3Al

1

2

3

4 [1] C. von Hänisch, F. Weigend, O. Hampe, S. Stahl, Chem. Eur. J. 2009, 15, 9642.

Poster 12

IRIS-13 Victoria

100

Generation of Tellurenyl Cation Species (RTe+): Structures and Properties of Tellurophenium Salts

Koh Sugamata, Takahiro Sasamori and Norihiro Tokoitoh

(sugamata@boc.kuicr.kyoto-u.ac.jp)

Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan Tellurenyl cations, RTe+, have attracted much attention for a long time. However, only a few stable examples are known due to their difficulty to isolate because of their intrinsic high reactivity. Although a tellurenyl cation derivative, [2,6-(Me2NCH2)2C6H3Te]+ PF6

–, stabilized by intramolecular coordination of amino group was reported, no structural feature has been disclosed.[1] On the other hand, methyl- or 4-fluorophenyl-substituted ditelluride was reported to be oxidized by a nitrosonium salt giving the corresponding transient species of tellurenyl cation.[2] In recent studies, the synthesis of an aryltellurenyl cation stabilized by the coordination of NHC was reported by Beckmann.[3] We expected that the chemical trapping products of low-coordinated tellurenyl cation species can be kinetically stabilized by a bulky aryl group such as Bbt group (see Figure). The dehalogenation reactions of Bbt-substituted tellurium halides[4] are rational to postulate the formation of a tellurenyl cation species as an intermediate.[5] In this presentation, we present the successful trapping reactions of a tellurenyl cation species with butadienes to give the corresponding 2,5-dihydrotellurophenium salts as stable colorless compounds. The re-generation of the tellurenyl cation species by its thermal retro[1+4]cycloaddition will also be described.

[1] H. Fujihara, H. Mima, N. Furukawa, J. Am. Chem. Soc. 1995, 117, 10153. [2] C. Kollemann, F. Sladky, J. Organomet. Chem. 1990, 396, C1. [3] J. Beckmann, P. Finke, S. Heitz, M. Hesse, Eur. J. Inorg. Chem. 2008, 1921. [4] a) T. Sasamori, Y. Arai, N. Takeda, R. Okazaki, Y. Furukawa, M. Kimura, S. Nagase, N. Tokitoh,

Bull. Chem. Soc. Jpn. 2002, 75, 661; b) T. Sasamori, Y. Arai, N. Takeda, R. Okazaki, N. Tokitoh, Chem. Lett. 2001, 42.

[5] a) T. Sasamori, K. Sugamata, N. Tokitoh, Heteroatom Chem. 2011, 22, 405; b) K. Sugamata, T. Sasamori, N. Tokitoh, Chem. Asian J. 2011, 6, 2301. [6] K. Sugamata, T. Sasamori, N. Tokitoh, Eur. J. Inorg. Chem. 2011, 5, 775.

Poster 13

IRIS-13 Victoria

101

Mechanistic Insights into the Formation of Phosphorus-Containing Ruthenacycles

K. Morrowa, L. Rosenberga, D. Pantazisb and R. McDonaldc

(kmorrow@uvic.ca)

a) University of Victoria, Department of Chemistry, b) Max Plank Institute for Bioinorganic Chemistry

c) University of Alberta, X-Ray Crystallography Department Phosphorus-containing metallacycles formed from the overall [2+2]-cycloaddition of terminal alkenes at a Ru-P -bond[1] show promise as possible intermediates relevant to catalytic hydrophosphination. We have investigated the formation of these complexes in detail. In confirmation of DFT predictions, we have directly observed an 2-alkene adduct as an intermediate in the [2+2] cycloaddition. We have also demonstrated, through the construction of a Hammett plot showing non-linearity, that the mechanism of ruthenacycle formation is dependent on alkene substituent electronics. The formation of these phosphorus-containing ruthenacycles may occur via a more stepwise mechanism for electron-deficient alkenes as opposed to the concerted [2+2] cycloaddition of electron-rich alkenes.

RuPh3P

PCy2

R

H

RuPh3P

PCy2

H

R

+

syn anti

HC CH2

RuPh3P PCy2

R

RuPh3P PCy2

R

+

[1] Derrah, E. J.; Pantazis, D. A.; McDonald, R.; Rosenberg, L. Angew. Chem., Int. Ed. 2010, 49, 3367.

Poster 14

IRIS-13 Victoria

102

Functionalized Tris(pyrazolyl)borate and Tris(pyrazolyl)borate ligands as Potential PARACEST MRI Contrast Agents

Emma Nicholls-Allison and David Berg

(ecna@uvic.ca) Department of Chemistry, University of Victoria, Victoria, BC, Canada

Traditional MRI contrast agents employ high dosages of gadolinium containing chelates in order to generate a suitable image in situ. However, toxicity concerns and depleting resources of the gadolinium metal have promoted studies into a new type of contrast agent utilizing a PARACEST mechanism. The crucial features of the ligand design are strong ligand-metal binding, exchangeable protons on the periphery, and water solubility. It is with these features in mind that we are studying both the tris(pyrazolyl)borate and tris(triazolyl)borate ligand systems. By installing a chelating group at the three position, the borate ligand can act as a hexacoordinate system, thus decreasing the ligand-metal lability. By introducing novel, functionalized groups at the three position, exchangeable protons can be introduced in order both participate in the PARACEST mechanism and increase the water solubility. Thus far, the coordination chemistry of a variety of novel, chelating tris(pyrazolyl)borate ligands has been studied.

Poster 15

IRIS-13 Victoria

103

Synthesis of 1,2:3,4-Bis(ferrocene-1,1’-diyl)tetragermetane and its Photochemical Reaction

Hisashi Miyamoto, Takahiro Sasamori and Norihiro Tokitoh

(miyamoto@boc.kuicr.kyoto-u.ac.jp) Institute for Chemical Research, Kyoto University, Japan

There has been much interest in intramolecular electronic interaction between transition metals (d-electrons) through an organic -electron conjugated system.[1] On the other hand, double-bond compounds between heavier group 14 elements are known to exhibit higher HOMO and lower LUMO levels relative to those in olefins. We have already reported the synthesis and properties of 1,2-bis(ferrocenyl)digermene as a novel d- conjugated system.[2] Recently, we have shifted our attention towards the synthesis of 1,2-ferrocene-1,1’-diyldigermene 1. Attempted reductive ring-closing reactions of 1,1’-bis(dibromogermyl)ferrocene 3 resulted in the formation of the dimer of digermene 1, 1,2:3,4-bis(ferrocene-1,1’-diyl)tetragermetane 2 as a stable crystalline compound. We would like to report herein the detailed synthesis and photochemical reactivity of tetragermetane 2. When tetragermetane 2 was exposed to photo-irradiation from a medium pressure Hg lamp in benzene at room temperature, trigermirane 4 was exclusively obtained. Photochemical reactions of 2 in the presence of trapping reagents such as methanol and triethylsilane will also be described.

[1] Demadis, K. D.; Hartshorn, C. M.; Meyer, T. J. Chem. Rev. 2001, 101, 2655. [2] Sasamori, T.; Miyamoto, H.; Sakai, H.; Furukawa, Y.; Tokitoh, N. Organometallics 2012, 31, 3904.

ORTEP drawing of 2 (left) and 4 (right) at 30% probability. Hydrogen atoms and i-Pr groups are omitted for clarity.

Poster 16

IRIS-13 Victoria

104

Unexpected Formation of Novel 1,2,3-Tri-substituted 1H-2,1-Benzazaboroles by Amidolithiation of Dichloroboro-substituted N,C-Chelating Ligands

Martin Hejdaa, Antonín Lyčkab, Roman Jambora, Aleš Růžičkaa and Libor Dostála*

(libor.dostal@upce.cz)

a Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, Pardubice CZ-532 10, Czech Republic,

b Research Institute for Organic Syntheses, Rybitví 296, CZ-533 54 Pardubice, Czech Republic An attempt to prepare precursors of intramolecularly coordinated boramidinates[1] (top of Fig. 1) containing N,C-chelating ligands via nucleophilic substitution of chlorine atoms by lithium anilides led, in one step and good yields, to unexpected and unprecedented formation of B-N heterocyclic compounds: novel 1,2,3-tri-substituted 1H-2,1-benzazaborols (bottom of Fig. 1). These structures are rare; only a few 1H-2,1-benzazaboroles substituted in the positions 1,2 and 3 are known[2]. However, these already known 1H-2,1-benzazaboroles are generally accessible by more complicated reaction protocols. Furthermore, the observed compounds contain two NH functionalities, which may be deprotonized and used as reactants for further reactions. Depending on the temperature and the stoichiometry used in the studied reactions, the substitution of two anilide groups can be directed to either 1,3- or 1,2- positions of benzazaborole cycle (bottom of Fig. 1). The hot results extending this topic will be presented and discussed.

Figure 1

The authors thank the Grant Agency of the Czech Republic for financial support (Projects No. P207/10/0130 and P207/12/0223). [1] C. Fedorchuk, M. Copsey, T. Chivers, Coord. Chem. Rev. 2007, 251, 897-924. [2] (a) A. Rydzewska, K. Ślepokura, T. Lis, P. Kafarski, P. Młynartz, Tetrahedron Lett. 2009, 50, 132-

134. (b) A. M. Genaev, S. M. Nagy, G. E. Salnikov, V. G. Shubin, Chem. Commun. 2000, 1587-1588.

Poster 17

IRIS-13 Victoria

105

Synthesis of Heteroboroxines of 14 and 15 Group Elements

Barbora Mairychová, Tomáš Svoboda, Roman Jambor and Libor Dostál (roman.jambor@upce.cz)

Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, Pardubice CZ-532 10, Czech Republic

Boroxines are well known species, easily accessible by dehydration of the corresponding organoboronic acids.[1] In 2005, Yaghi and coworkers reported on the synthesis and characterization of the first crystalline boroxine covalent organic framework (COF).[2] Since the disclosure of this COF many COF-related materials emerged, which significantly expanded the interest in material properties of boroxines. The chemistry of heteroboroxines, in which one of the boron atom is substituted by a heteroatom M to form a MB2O3 six-membered ring, remains nearly unexplored despite of an extensive research in the field.[2] As the result of our investigation of main group organometallic compounds,[3] we report herein a straightforward synthetic strategy for the synthesis of unprecedented heteroboroxines LM[(OBR)2O] and L(Ph)Sn[(OBR)2O], where M = Sb and Bi, L = [2,6-bis(dimethylamino)methyl]phenyl, R = Ph, 4-CF3C6H4 and ferrocenyl), comprising the MB2O3 six membered rings (Figure 1).

OB

OB

OM

L

RR

OB

OBO

SnL

RR

PhNMe2

NMe2

= L

R M Ph Sb: 1a Bi: 2a 3a4-CF3C6H4 Sb: 1b Bi: 2b 3b 1-ferrocenyl Sb: 1c Bi: 2c 3c

Figure 1

The authors wish to thank the Grant agency of the Czech Republic project no. P106/10/0443. [1] D. G. Hall, G. C. Frye, in Boronic Acids, WILEY-VCH, Weinheim, 2005. [2] (a) X. Ma, Z. Yang, X. Wang, H. W. Roesky, F. Wu, H. Zhu, Inorg. Chem. 2011, 50, 2010-2014; (b)

Z. Yang, X. Ma, R.B. Oswald, H. W. Roesky, M. Noltemeyer, J. Am. Chem. Soc. 2006, 128, 12406-12407.

[3] (a) P. Šimon, F. de Proft, R. Jambor, A. Růžička, L. Dostál, Angew. Chem. Int. Ed. 2010, 49, 5468. (b) M. Bouška, L. Dostál, A. Růžička, L. Beneš, R. Jambor, Chem. Eur. J. 2011, 17, 450. (c) M. Bouška, L. Dostál, F. de Proft, A. Růžička, A. Lyčka, R. Jambor, Chem. Eur. J. 2011, 17, 455. (d) M. Bouška, L. Dostál, Z. Padělková, A. Lyčka, S. Herres-Pawlis, K. Jurkschat, R. Jambor, Angew. Chem. Int. Ed. 2012, 51, 3478.

Poster 18

IRIS-13 Victoria

106

Organometallic Group 14 And 15 Chalcogenides and Phenylchalcogenides

Marek Bouška, Petr Šimon, Roman Jambor, Antonín Lyčka and Libor Dostál (libor.dostal@upce.cz)

Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, Pardubice CZ-532 10, Czech Republic, Research Institute for Organic

Syntheses, Rybitví 296, CZ-533 54 Pardubice, Czech Republic

We have recently demonstrated that using of NCN chelating, so called pincer type, ligands allowed isolation of several group 14 and 15 element molecular chalcogenides (E = S, Se, Te), that in some cases contain unprecedented terminal M-E bonds or unprecedented ring systems such as M(-S5)M or MS4.[1] These compounds were prepared either by oxidative addition of elemental chalcogens to low valent metal precursors or by the reaction of the parent organometallic chlorides with alkali metal chalcogenides Li2E (E = S, Se, Te). As a part of our ongoing interest in the group 14 and 15 element chalcogenides, we are also interested in preparation of group 15 chalcogenides kinetically stabilized by a bulky ligand (Fig. 1) or in corresponding arylchalcogenides synthesized by the oxidation of low valent precursors, especially tin(I), antimony(I) and bismuth(I) compounds, with diaryldichalcogenides (Fig. 1). The fresh results targeting these two targets will be presented and discussed.

Figure 1

The authors wish to thank the Grant agency of the Czech Republic project no. P207/10/0130. [1] (a) P. Šimon, F. de Proft, R. Jambor, A. Růžička, L. Dostál, Angew. Chem. Int. Ed. 2010, 49, 5468.

(b) L. Dostál, R. Jambor, A. Růžička, A. Lyčka, J. Brus, F. de Proft, Organometallics 2008, 27, 6059. (c) L. Dostál, R. Jambor, A. Růžička, R. Jirásko, V. Lochař, L. Beneš, F. de Proft, Inorg. Chem. 2009, 48, 10495. (d) M. Bouška, L. Dostál, A. Růžička, L. Beneš, R. Jambor, Chem. Eur. J. 2011, 17, 450. (e) M. Bouška, L. Dostál, F. de Proft, A. Růžička, A. Lyčka, R. Jambor, Chem. Eur. J. 2011, 17, 455. (f) P. Šimon, R. Jambor, A. Růžička, A. Lyčka F. de Proft, L. Dostál, Dalton Trans. 2012, 41, 5140. (g) M. Bouška, L. Dostál, Z. Padělková, A. Lyčka, S. Herres-Pawlis, K. Jurkschat, R. Jambor, Angew. Chem. Int. Ed. 2012, 51, 3478.

Poster 19

IRIS-13 Victoria

107

New Applications of Woollins’ Reagent for the Synthesis of Small Organoselenium Heterocycles to Macro Phosphorus/Selenium Heterocycles

Guoxiong Hua, Junyi Du, Rebecca A. M. Randall, Alexandra M. Z. Slawin and J. Derek Woollins

(gh15@st-andrews.ac.uk) School of Chemistry, University of St Andrews, Fife, KY16 9ST, UK

2,4-Bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide [{PhP(Se)(µ-Se)}2], Woollins’ Reagent, WR, a selenium analogue of the well-known Lawesson’s Reagent (2,4-bis(p-methoxyphenyl)-1,3-dithioadiphosphetane-2,4-disulfide, LR), has less unpleasant chemical properties and can be prepared readily and safely handled.[1] Now it is commercial available in the Sigma-Aldrich catalogue (No: 572543). WR has been becoming a very useful selenium source or building block in synthetic chemistry in recent years.[2] In this poster, we demonstrate its new reactivities towards the organic substituents. Refluxing a mixture of equimolar amount of WR and cyanamides in toluene, followed by quenching with water led to the formation of phenethylselenoureas, the latter were treated with equimolar ArCOCH2X giving a series of 4-aryl-N-alkyl-N-phenethyl-1,3-selenazol-2-amines in excellent yields; meanwhile, reacting WR with an equivalent of disodium alkyldiols, followed by ring-closure treatment with appropriate dihaloalkanes resulted in the corresponding nine- to fifteen-membered phosphorus-selenium heterocycles in medium to good yields.

[1] P. Gray, P. Bhattacharyya, A. M. Z. Slawin, J. D. Woollins, Chem. Eur. J. 2005, 11, 6221. [2] (a) A. Rothenberger, W. Shi, M. Shafaei-Fallah, Chem. Eur. J. 2007, 13, 5974. (b) P. Amaladass, N.

S. Kumar, A. K. Mohanakrishnan, Tetrahedron 2008, 64, 7992. (c) G. Hua, J. D. Woollins, Angew. Chem. Int. Ed. 2009, 48, 1368. (d) G. Hua, J. B. Henry, Y. Li, A. R. Mount, A. M. Z. Slawin, J. D. Woollins, Org. Biomol. Chem. 2010, 8, 1655. (e) G. Hua, J. M. Griffin, S. E. Ashbroom, A. M. Z. Slawin, J. D. Woollins, Angew. Chem. Int. Ed. 2011, 50, 4123. (f) G. Hua, A. M. Z. Slawin, J. D. Woollins, Synlett 2012, 23, 1170. (g) J. A. Gómez Castaño, R. M. Romano, H. Beckers, H. Willner, C. O. Della Védova, Inorg. Chem. 2012, 51(4), 2608.

Poster 20

IRIS-13 Victoria

108

Unexpected Dehalogenation Reactions of Dichloroborane Bearing a NCN-Pincer Ligand

Masaichi Saito,a Kaori Matsumotoa and Mao Minourab

(masaichi@chem.saitama-u.ac.jp) aDepartment of Chemistry, Graduate School of Science and Engineering, Saitama University, Shimo-

okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan bDepartment of Chemistry, School of Science, Kitasato University, Kitasato, Sagamihara, Kanagawa,

228-8555, Japan

The synthesis of cationic and anionic boron species is of considerable interest from the viewpoint of fundamental curiosity and their potential usefulness as ligands and catalysts. In the course of our studies on the synthesis of dianionic species of main group elements,[1] we became interested in the synthesis of dicationic and dianionic boron species that have the same carbon ligands on the boron atoms. We then chose 2,6-bis[(diisopropylamino)methyl]- phenyl group, an NCN-pincer ligand, as a protecting group on the reactive boron center, which is utilized to stabilize reactive species of Group 13 elements.[2] We report herein the synthesis of novel dichloroborane 1 bearing an NCN-pincer ligand, which reacts with AgBF4 in the absence and the presence of pyridine to afford unexpected borenium salt 2 and difluoroborane 3, respectively. Reduction of 1 is also demonstrated. 2,6-Bis[(diisopropylamino)methyl]phenyllithium 4 reacted with trichloroborane etherate to afford dichloroarylborane 1. Reaction of 1 with AgBF4, however, afforded an unexpected product, borenium salt 2. In the presence of pyridine, difluoroborane 3 was obtained. The formation of 2 and 3 suggests the generation of intermediary boron dication 5.

[1] For a review, see: Saito, M. Coord. Chem. Rev. 2012, 256, 627. [2] (a) Contreras, L.; Cowley, A. H.; Gabbaï, F. P.; Jones, R. A.; Carrano, C. J.; Bond M. R. J.

Organomet. Chem. 1995, 489, C1. (b) Schlengerann, R.; Sieler, J.; Hey-Hawkins, E. Main Group Chem. 1997, 2, 141. (c) Dostál, L.; Jambor, R.; Růžička, A.; Jirásko, R.; Císařová, I.; Holeček, J. J. Organomet. Chem. 2006, 691, 35.

BriPr2N NiPr2 tBuLiEt2O iPr2N NiPr2

NiPr2iPr2N Li Li

4

BCl3-OEt2 BiPr2N NiPr2

ClCl

1

AgBF4 (2 equiv.)

BiPr2N NiPr2

FF

BiPr2N NiPr2O

2

3

CH2Cl2, r. t.

CH2Cl2, r. t.

AgBF4 (2 equiv.)pyridine

5

B +

BF4

BiPr2N NiPr22+

F2

Poster 21

IRIS-13 Victoria

109

Studies on Platinum Complexes of 1,8-Naphthosultone and 1,8-Naphthosultam

Louise M. Diamond, Fergus R. Knight, Alexandra M. Z. Slawin and J. Derek Woollins

(ld397@st-andrews.ac.uk) School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, Scotland, UK

In the late 1970’s and early 1980’s Teo and co-workers[1] coordinated tetrathionaphthalene (TTN), tetrachlorotetrathionaphthalene (TCTTN) and tetrathiotetracene (TTT) to a Pt(PPh3)2 motif through an oxidative addition reaction with [Pt(PPh3)4]. We[2] have used this oxidative reaction to study the coordination chemistry of 1, 8-dichalcogen naphthalenes and the oxidised derivatives of naphtho [1,8-cd] 1,2-dithiole, to platinum bisphosphines. Here, a series of platinum bisphosphine complexes bearing 1,8-naphthosultone as a bidentate ligand have been prepared. An analogous reaction was studied with 1,8-naphthosultam. However, it was found that 1,8-naphthosultam acts as a monodentate ligand. Thus, for example, reaction of 1,8-naphthosultone with [PtCl2(PPh3)2] gives [Pt(1-(SO2),8-(O)-nap)(PPh3)2] (1) whereas reaction of 1,8-naphthosultam with [PtCl2(PPh3)2] gives [Pt(1-(SO2),8-(N)-nap)(PPh3)(Cl)] (2).

Figure. X-ray crystal structures of complexes (1) and (2) with hydrogen atoms omitted for clarity

Further studies into more electron rich peri substituted systems will also be reported.

[1] B. K. Teo, F. Wudl, J. H. Marshall and A. Krugger, J. Am. Chem. Soc., 1977, 99, 2349; B. K. Teo, P.

A. Snyder-Robinson, Inorg. Chem., 1978, 17, 3489; B. K. Teo, P. A. Snyder-Robinson, Inorg. Chem., 1979, 18, 1490; B. K. Teo, P. A. Snyder-Robinson, Inorg. Chem., 1981, 20, 4235.

[2] S. M. Aucott, H. L. Milton, S. D. Robertson, A. M. Z. Slawin, G. D. Walker and J. D. Woollins, Chem. Eur. J., 2004, 10, 1666.

Poster 22

IRIS-13 Victoria

110

Activation of White Phosphorus

Laura Forfar, Nicholas Norman and Chris Russell (laura.forfar@bristol.ac.uk)

School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK The activation of white phosphorus is a topic of current interest and seeks to find a more sustainable and environmentally friendly route into the production of organophosphorus compounds which have uses in the food, agricultural and pharmaceutical industries. This can be done by early transition metals, late transition metals and main group elements and compounds. In this work we sought to activate white phosphorus using the group 11 metals. We achieved this by reaction of equimolar amounts of simple inorganic salts, MX (M = Au, Cu, X = Cl; M = Ag, X = OTf) with a Lewis acid (GaCl3) and P4 in a CH2Cl2 solution. 31P NMR spectroscopy showed a downfield shift in all cases, being more pronounced for Au (-452) than for Cu (-499) and Ag (-513 ppm). In the solid state, the compounds showed remarkably different structures. Cu and Ag formed coordination polymers based on P4MGaCl4 in ion-contacted structures. For copper, Cu+, GaCl4 and P4 units are all involved in the central framework forming the first example of a coordination polymer where P4 is an integral part of the bonding network. For silver, Ag+ and GaCl4

- units are linked through bridging chloride ligands to form a ladder structure with each Ag bonded η2- to a P4 unit.

For gold, different chemistry resulting in an ion-separated structure is observed. [Au(η2-P4)2]+ cations ion-separated from [GaCl4]- anions form the first homoleptic P4 complex of gold.[1] This complex, predicted to be the most stable homoleptic group 11 cation of the type [(η2-P4)2M]+ is the final member of the series to be found.[2]

[1] Forfar, L; Clark, T; Green, M; Mansell, S; Russell, C; Sanguramath, R; Slattery, J, Chem Commun, 2012¸ 48, 1970

[2] a) Krossing, I; J. Am. Chem. Soc., 2001, 123, 4603 b) Santiso-Quiñones, G; Reisinger, A; Slattery, J; Krossing, I, Chem Commun, 2007, 5046

P

P

Cu

Ag

Au

P

P P P

P P

P P

Ga

Cl

Cl Cl

Cl

Cl Ga

P P

P P

Cl

Cl Cl

Cl Cl

Ga

Ga

P P

Cu

Poster 23

IRIS-13 Victoria

111

Novel P,N Cage Ligands via Rearrangement of Azaphosphiridine Complexes

José Manuel Villalba Franco and Rainer Streubel (villalba@uni-bonn.de)

Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms Universität Bonn Gerhard-Domagk Str. 1, 53121 Bonn, Germany

2H-Azaphosphirene[1] and azaphosphiridine[2] complexes were reported first by Streubel and co-workers. The former have provided access to various P,N- and P,O-cage ligands via thermally induced rearrangements.[3] Very recently, new derivatives of azaphosphiridine complexes were synthesized via reaction of a transient Li/Cl phosphinidenoid complex (route i) or a thermally generated terminal phosphinidene complex (route ii) and N-methyl C-aryl imines.[4] Here, we report on generation and rearrangements of labile P-Cp* substituted azaphosphiridine complex 4a,b that lead to two novel type of P,N cage complexes 5a,b and 6a,b. The 31P NMR spectroscopic reaction monitoring for route i in the b case, showed transient P-Cp* aza-phosphiridine complex 4b at low temperature which undergoes rapid isomerisation to com-plex 5b. Under thermal conditions the formation of the novel P-N cage complexes 6a-b was observed. Further studies revealed a unique equilibrium between both cage-type ligands.[5]

NMR data as well as X-ray structures of the new complexes will be reported.

[1] R. Streubel, Coord. Chem. Rev. 2002, 227, 175-192. [2] R. Streubel, A. Ostrowski, H. Wilkens, F. Ruthe, J. Jeske, P. G. Jones, Angew. Chem. Int. Ed. Engl.

1997, 36, 378-381. [3] a) R. Streubel, U. Schiemann, N. Hoffmann, Y. Schiemann, P. G. Jones, D. Gudat, Organometallics

2000, 19, 475-481 ; b) M. Bode, G. Schnakenburg, P. G. Jones, R. Streubel, Organometallics, 2008, 27, 2664-2667.

[4] a) S. Fankel, H. Helten, G. von Frantzius, G. Schnakenburg, J. Daniels, V. Chu, C. Müller, R. Streubel. Dalton Trans. 2010, 39, 3472-3481; b) R. Streubel, J. M. Villalba Franco, G. Schnakenburg, A. Espinosa Ferao, Chem. Commun., 2012,48, 5986-5988.

[5] J.M. Villalba Franco, A. Espinosa, G. Schnakenburg, R. Streubel, manuscript in preparation.

Poster 24

IRIS-13 Victoria

112

Role of Non-Innocent Pyridine Ligands in the Isolation of Unprecedented Ge(0) and Sn(0) Complexes

Johanna Flock, Amra Suljanovic, Ana Torvisco, Michaela Flock and Roland C. Fischer

(johanna.flock@tugraz.at) Institut für Anorganische Chemie, TU-Graz, Stremayrgasse 9, A-8010 Graz, Austria

Recently, a novel type of Group 14 compounds has been developed, where the Group 14 elements are in the formal oxidation state of zero.[1] Group 14 elements in an formal oxidation state of zero are found in compounds where, for example, the E=E core (E= Si2, Ge3) is coordinated by two Lewis base carbene ligands. Other examples of formal E(0) species are “non classical” allenes R2E=E’=ER2 (E, E’= C, Si, Ge, Sn).[2] However, in literature no example of a neutral mononuclear compound is reported where a heavier main group atom is stabilized by only one donor molecule in an oxidation state of zero. Herein, we report neutral and mononuclear Ge0 (1a) and Sn0 (1b) complexes, which are stabilized by the DIMPY ligand, a Ge0 complex (2) stabilized by MIMPY (2-[ArN=C(H or Me)](NC5H3) (Ar= C6H3-2,6-iPr2))[3] and further low valent SnII species, as a MeDIMPYSnII (3) (Figure 1). The experimental results were also supplied by theoretical studies. The DIMPY ligand (2,6-[ArN=C(H)]2(NC5H3) (Ar= C6H3-2,6-iPr2) had previously been employed in the synthesis of highly reactive main group element complexes in low oxidation states, which are exclusively cationic.[3] The particular property of these ligands is the fact that these are non-innocent ligands and undergo electron-transfer reactions.[4] The Synthetic pathways, spectroscopic and structural features as well as computational results of these Ge0, Sn0 and SnII complexes will be discussed.

Figure 1.: Crystal structure of Sn(0) di(imino)pyridine complex (1b), the Sn(I) chloride di(imino)pyridine complex (2b) (L= 2,6-[DippN=C(H or Me)]2(NC5H3)) and the aromatic germylene (3) (L= 2-[DippN=C(H or Me)](NC5H3)). [1] Martin D., Soleilhavoup M., Bertrand G. Chem. Sci. 2011, 2, 389-399. [2] (a) Tonner R., Frenking G. Angew. Chem., Int. Ed 2007, 46, 8695-9698. (b) Tonner R., Frenking G.

Chem. Eur. J. 2010, 16, 10160 – 10170. (c) Dyker C. A., Lavallo V., Donnadieu B., Bertrand G. Angew. Chem. Int. Ed. 2008, 47, 3206 –3209. (d) Ishida S., Iwamoto T., Kabuto C., Kira M., Nature, 2003, 421, 725-727. (e) Wiberg N., Lerner H. W., Vasisht S. K., Wagner S., Karaghioso K., Nöth H., Ponikwar W. Eur. J. Inorg. Chem. 1999, 1211-1218

[3] (a) Benko, Z.; Burck, S.; Gudat, D.; Nieger, M.; Nyulaszi, L.; Shore, N., Dalton Trans. 2008, 4937-4945. (b) D. L. Reger, T. D. Wright, M. D. Smith, A. L. Rheingold, S. Kassel, T. Concolino, B. Rhagitan, Polyhedron 2002, 21, 1795-1807.

[4] a) Martin C. D., Ragogna P. J., Dalton Trans. 2011, 11976-11980. b) Ragogna, P. J., J. Am. Chem. Soc. 2009, 131, 15126-15127; Reeske, G.; Cowley, A. H., Chem. Commun. 2006, 1784-1786. c) Baker, R. J.; Jones, C.; Kloth, M.; Mills, D. P., New. J. Chem. 2004, 28, 207-213. d) Ullah, F.; Oprea, A. I.; Kindermann, M. K.; Bajor, G.; Veszpremi, T.; Heinicke, J., J. Organom. Chem., 2009, 694, 397-403.

(1b)

Ge N1

N2 C2

C1 Sn

N1

N3

N2 Sn

N1 N3

N2

Si

(2) (3)

Poster 25

IRIS-13 Victoria

113

Cyclization of Low Valent Main Group 3 and 4 Element Compounds

Petra Wilfling, Stefan Müller, Michaela Flock and Roland C. Fischer (petra.wilfling@tugraz.at)

Institut für Anorganische Chemie, TU Graz, Stremayrgasse 9/IV, 8010 Graz, Austria

A significant approach towards the synthesis of main group element compounds in unusual oxidation states is the use of sterically demanding ligands, particularly of terphenyl systems.[1] Among the various kinds of compounds containing main group 4 elements in unusual oxidation states, molecules including heavier elements in aromatic systems take an especially interesting position due to their rareness.[2] This presentation will mainly focus on the synthetic routes towards cyclic and aromatic Ge containing compounds stabilized by terphenyl ligands as well as their heavier analogues (see figure 1). Furthermore, the synthesis of metalloid Ga clusters[3], which are outstanding due to their exceptional intermediate state between elemental metal and molecular compound[4], will be discussed. Characterization of the products was performed employing spectroscopic (multinuclear NMR, UV-Vis, X-ray diffraction) and computational methods. Experimental and computational trends concerning structures, stabilities, NMR shifts and UV-Vis spectra but also chemical reactivity will be presented.

Figure 1: Cyclization of precursors containing heavier group 4 elements, obtained by conversion of terphenyl stabilized tetrylenes with phosphaalkynes . [1] see e.g.: Rivard, E.; Power, P.P. Inorg. Chem. 2007, 32, 10047-10064. [2] see e.g.: Tokitoh, N. Acc. Chem. Res. 2004, 37, 86-94. [3] Wilfling, P.; Fischer, R.C. unpublished results. [4] Driess, M.; Nöth, H. Molecular Clusters of the Main Group Elements, 1st ed.; Wiley- VCH:

Weinheim, 2004.

Poster 26

IRIS-13 Victoria

114

Toward Connection of Ruthenium Complexes to Tin/Sulfur Clusters.

Eliza ter Jung and Stefanie Dehnen (Jungel@students.uni-marburg.de)

Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße, D-35043 Marburg, Germany

In recent years, the design of ruthenium complexes has attracted great interest due to their properties, which are useful for diverse applications: the utilization of Ru(II) complexes ranges from dye-sensitized solar cells[1] and chromophores[2] to water oxidation[3], for instance. Many of these complexes include N-donor-, chelating ligands like terpyridines.[1] In our group, we have developed the ligands of organotetrel-chalcogenide cages, especially a double-decker-like RSn/S cluster and an adamantane-like RGe/S cluster, both of which are based on an inorganic Tt4S6 core (Tt = tetrel), to make the organic shell reactive toward further functionalization. Starting out from a keto-functionalized ligand R = CMe2CH2COMe, reactions with hydrazines, hydrazones or hydrazides have been successful (scheme 1).[4]

Scheme 1: Core-Rearrangement and/or functionalization of the double-decker-like cage [(RSn)4S6] (R = CMe2CH2COMe) with phenylhydrazine (left) or hydrazine (right), respectively.

To combine the versatile properties of the inorganic cluster core with the potentially applicable properties of Ru(II) complexes, one of our current aims is to attach these to an Sn/S cage. This can be achieved following different ways, either by functionalization of the Sn/S cluster with a suitable donor ligand and subsequent Ru(II) semi-sequestration, or by attachment of one of the ligands of a pre-formed Ru(II) complex to the cluster. So far, it was possible to connect a bipyridyl ligand to the cluster via an azine bond. This precursor is currently tested in reactions with coordinatively unsaturated Ru(II) complexes, according to the first synthetic route (scheme 2).

Scheme 2: Conversion of a donor-functionalized Sn/S precursor with a Ru(II) complex.

[1] P. G. Bomben, T. J. Gordon, E. Schott, C. P. Berlinguette, Angew. Chem. 2011, 123, 10870-10873. [2] K. C. D. Robson, C. P. Berlinguette et al., Inorg. Chem. 2011, 50, 5494-5508. [3] B. Radaram, X. Zhao et al., Inorg. Chem. 2011, 50, 10564-10571. [4] Z. Hassanzadeh Fard, L. Xiong, C. Müller, M. Holynska, S. Dehnen, Chem. Eur. J. 2009, 15, 6595-6604.

Poster 27

IRIS-13 Victoria

115

An Efficient Approach to Ternary Intermetalloid Clusters: Reactions of Binary Zintl Anions with Transition Metal Complexes

Bastian Weinert, Rodica Ababei and Stefanie Dehnen

(Weinertb@students.uni-marburg.de) Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße, D-35043 Marburg,

Germany

Intermetalloid clusters,[1] which combine main group (semi-)metals with transition metal clusters, belong to the most recent developments in the field of Zintl anion chemistry and physics.[2] So far, the clusters have usually been obtained by reacting solutions of Zintl phases A4Tt9 or A3Pn7 (A: alkali metal, Tt: tetrel, Pn: pnictogen), which comprise homoatomic anions, in liquid NH3 or en/[2.2.2]crypt with transition metal compounds. However, due to a relatively high charge, most of the phases with molecular tetrel polyanions, e.g. A4Tt4, show poor solubility,[3] which has complicated reactions of further species. To overcome this problem, and to add another degree of freedom regarding the electron number of the resulting clusters, we recently extended this approach by using binary Zintl anions with a combination of Group 14/15 elements as well-soluble precursors, namely [Sn2Sb2]2−, [Sn2Bi2]2−, with only 2− charge according to the Zintl-Klemm-Busmann[4] pseudo element concept. This has led to the generation of a large variety of ternary anions such as [Pd3@Sn8Bi6]4–, [Ln@Sn7Bi7]4− and [Ln@Sn4Bi9]4− (Ln = La, Ce).[5,6] Our current investigations again extent this field by transferring our approach to the employment of pseudo-homoatomic precursors [Sn2Sb2]2− [7] and [Pb2Bi2]2−, and to the Group 13/15 element combination [GaBi3]2− and [InBi3]2−.[8] Here, we present first results of this variation that indicate the subtle influence of charges, atomic radii and Lewis basicities of the involved elements. Isostructural element substitutions were observed in [Zn@Zn5Pb3Bi3@Bi5]4–, [Ni2@Pb7Bi5]3–, [Ln@Pb7Bi7]4− and [Ln@Pb4Bi9]4−. Interestingly with Ln = La, Ce, Nd, we also obtained clusters with novel structures or different charges, {[La@In2Bi11](µ-Bi)2[La@In2Bi11]}6− or [La@Sn6Sb8]3–. Besides characterization of the compounds, our studies include formation mechanisms and electronic structures of the uncommon intermetalloid cages.

[1] T. F. Fässler, S. D. Hoffmann, Angew. Chem. Int. Ed. 2004, 43, 6242; [2] S. Scharfe, F. Kraus, S. Stegmaier, A. Schier, T. F. Fässler Angew. Chem. Int. Ed. 2011, 50, 3630; [3] M. Waibel, F. Kraus, S. Scharfe, B. Wahl, T. F. Fässler, Angew. Chem. Int. Ed. 2010, 49, 6611; [4] W. Klemm, E. Busmann, Z. Anorg. Allg. Chem. 1963, 319, 297; [5] F. Lips, R. Clérac, S. Dehnen, J. Am. Chem. Soc. 2011, 133, 14168; [6] F. Lips, M. Hołyńska, R. Clerac, U. Linne, I. Schellenberg, R. Pöttgen, F.Weigend, S. Dehnen, J. Am. Chem. Soc. 2012, 134, 1181; [7] F. Lips, I. Schellenberg, R. Pöttgen, S. Dehnen, Chem. Eur. J. 2009, 15, 12968; [8] L. Xu, S. C. Sevov, Inorg. Chem. 2000, 39, 5383.

Poster 28

IRIS-13 Victoria

116

Synthesis of Alumosilicates with Lanthanides and the Influence of Anagostic Interactions on the Conformation of their Rings

Vojtech Jancik,* Kimberly Thompson Montero, Marisol Reyes Lezama

(vjancik@unam.mx) Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carr. Toluca Atlacomulco km.

14.5, C.P. 50200, Toluca, Estado de México, México. *Academic staff from the Universidad Nacional Autónoma de México

A two-step synthesis from easily accessible precursors (AlMe3, (tBuO)2Si(OH)2 and Cp3Ln) leads to a facile formation of alumolsilicates with lanthanides containing a central 4R alumosilicate ring.[1] This ring is fused with two four-membered lanthanidosilicate rings to form a centrosymmetric molecule. The conformation of the molecules depends on the metal covalent radii and the presence and number of the anagostic interactions. These interactions are formed between one of the methyl groups of the AlMe2 unit and the lanthanide metal.

Figure 1. Molecular structure of the alumosilicate with gadolinium, comparison of the three different ring conformations and the deviation of the methyl group from the ideal orientation towards the aluminum atom. Thermal ellipsoids at 50 % probability only for noncarbon atoms. Hydrogen atoms have been omitted for clarity. [1] Kimberly Thompson Montero, Marisol Reyes Lezama, Vojtech Jancik, manuscript en preparation.

Poster 29

IRIS-13 Victoria

117

Tin Aminoalkoxides and their Platinum Complexes: Structural Diversity and Catalytic Activity in Polymerisation Reactions

T. Zöller, C. Dietz, L. Iovkova-Berends and K. Jurkschat

(thomas.zoeller@tu-dortmund.de) Lehrstuhl für Anorganische Chemie II der Technischen Universität Dortmund,

Otto-Hahn-Str. 6, 44227 Dortmund, Germany In cooperation with Bayer Material Science we found an excellent latent catalytic activity in polyurethane synthesis of inorganic tin compounds based on amino alcohol ligands.[1] Prominent representatives of these tin(II) and tin(IV) derivates are 2,8-dioxa-5-aza-1-stannabicyclo[3.3.0]octanes of the types R1N(CH2CR2

2O)2Sn and R1N(CH2CR22O)2SnX2 (R = alkyl, Ph, Me2NCH2CH2, MeOCH2CH2; X =

halogen, alkoxide etc.). These non-toxic compounds hold great potential to replace the commonly used mercury-based catalysts. A systematic variation of the substituents X and R allows controlling the switch-temperature of the catalysts but gives also access to great structural diversity. The tin aminoalkoxides are suitable to stabilize molecular tin(II) compounds such as tin(II) chloride oxide (1). Reactions with platinum complexes give unusual tin platinum clusters such as 2. The tin(II) compounds may act as -donor ligands, insert into Pt–Cl bonds or take part in rearrangement reactions. We also report enantiopure tin aminoalkoxides that hold potential for asymmetric induction in catalytic processes.[2]

[1] J. Krause, S. Reiter, S. Lindner, A. Schmidt, K. Jurkschat, M. Schürmann, G. Bradtmöller,

DE 102008021980, 2008. [2] (a) T. Zöller, L. Iovkova-Berends, T. Berends, C. Dietz, G. Bradtmöller, K. Jurkschat, Inorg. Chem.

2011, 50, 8645. (b) T. Zöller, L. Iovkova-Berends, C. Dietz, T. Berends, K. Jurkschat, Chem. Eur. J. 2011, 17, 2361. (c) K. Jurkschat, M. Schürmann, T. Zöller, L. Iovkova-Berends, DE 102010012237, 2010. (d) T. Zöller, C. Dietz, L. Iovkova-Berends, O. Karsten, G. Bradtmöller, A.-K. Wiegand, Y. Wang, V. Jouikov, K. Jurkschat, Inorg. Chem. 2012, 51, 1041.

Poster 30

IRIS-13 Victoria

118

Tellurium-Containing Heterocycles Stabilized by P2N2 Rings

Andreas Nordheider†‡, Tristram Chivers‡ , Thirumoorthi Ramalingam,‡ Ignacio Vargas-Baca#, Alexandra M. Z. Slawin† and J. Derek Woollins†

(an349@st-andrews.ac.uk) †University of St Andrews, Purdie Building, St Andrews, KY16 9ST, Scotland, UK

‡ University of Calgary, Calgary, AB T2N 1N4, Canada #McMaster University, Hamilton, L8S 4M1, Canada

Recently, we decribed a mild oxidative approach to generate the trimeric macrocycles [P2N2(µ-E–E–)]3 (E = S, Se) with a planar P6E6 framework in which dichalcogenido (–E–E–) groups are linked by perpendicular P(V)

2N2 rings.[1] This poster presents the results of the application of this approach to tellurium derivatives,[2] which provide important insights into the initial oxidation process, as well as notable differences in the final outcome of the oxidation compared to that observed for sulfur- or selenium-containing systems. Furthermore, we report metathetical reactions between the precursor dianion and various dihalides, which lead to a series of new heterocyclic tellurium compounds incorporating P2N2 rings. The products of these metatheses were characterized by multinuclear NMR spectroscopy (31P, 77Se, 125Te NMR.) and, in some cases, by X-ray crystallography. Figure 1: Novel phosphorus-tellurium heterocycles (left: representative scheme, right: crystal structure of a cyclic phosphorus-tritelluride). These novel compounds provide an opportunity for an in-depth investigation of the chemical behavior and structural parameters of phosphorus-tellurium heterocycles. Furthermore, the compounds offer considerable scope for new phosphorus-tellurium chemistry.

http://chemistry.st-andrews.ac.uk/staff/jdw/group/profjdwoollins.html [1] A. Nordheider, T. Chivers, R. Thirumoorthi, I. Vargas-Baca and J. D. Woollins, Chem. Commun.,

2012, 48, 6346. [2] G. G. Briand, T. Chivers and M. Parvez, Angew. Chem. Int. Ed., 2002, 41, 3468.

Poster 31

IRIS-13 Victoria

119

Experimental and Computational Studies of the Oxidation and Chalcogenation of the 1,4-C2P4 Ring

P. J. W. Eldera, T. Chivers,a T. L. Roemmeleb and R. T. Boeréb

(chivers@ucalgary.ca) a Department of Chemistry, University of Calgary, Calgary AB, Canada

b Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge AB, Canada

The chemistry of cyclophosphanes (RP)n (R = alkyl, aryl n = 3-6) has been extensively investigated in terms of both their tendency to undergo insertion and rearrangements with chalcogens[1] and their electrochemical properties.[2] The closely related cyclocarbaphosphanes however, have been less well studied. While insertion reactions have been reported for the CP4 ring with both selenium and sulphur, the PCP moiety has been shown to remain intact.[1,3] By contrast with these systems, there have been no reports of the chemical and/or redox properties of the related C2P4 six-membered ring, 1. The tert-butyl derivative 1 (R = tBu) is obtained in good yield from the reaction of Cl2PCH2PCl2 with four equivalents of tBuMgCl. Computational studies using DFT suggest a weak cross-ring P-P interaction for the radical cation of 1 (R = tBu), and a bicyclic system for the corresponding dication. Cyclic voltammetry shows two well-separated, but irreversible, waves at (a) 0.49 V (GC), 0.52 V (Pt) and (b) 1.08 V (GC), 1.16 V (Pt) in dichloromethane consistent with the formation of the mono- and di-cations. Experimental investigations of the oxidation of 1 (R = tBu) and a comparison of the chemical reactivity toward chalcogens will be presented.

[1] Review: G. Hua and J.D. Woollins, Angew. Chem. Int. Ed., 2009, 48, 1368. [2] H.-G. Schäfer, W. W. Schoeller, J. Niemann, W. Haug, T. Dabisch and E. Niecke, J. Am. Chem.

Soc. 1986, 108, 7481. [3] (a) P. Kilian, A. M. Z. Slawin and J. D. Woollins, Chem. Commun., 2001, 2288; (b) P. Kilian P.

Bhattacharyya, A. M. Z. Slawin and J. D. Woollins, Eur. J. Inorg. Chem., 2003, 1461.

Poster 32

IRIS-13 Victoria

120

Synthesis and Coordination Chemistry of Zwitterionic Pnictogen(I) Centers

Jonathan W. Dube1, Charles L.B. Macdonald2 and Paul J. Ragogna1 (jdube7@uwo.ca, pragogna@uwo.ca)

1Department of Chemistry and the Center for Materials and Biomaterials Research Western University, 1151 Richmond St, London, Ontario, N6A 5B7, Canada, 2Department of Chemistry

and Biochemistry, The University of Windsor, 401 Sunset Ave, Windsor, Ontario, N9B 3P4, Canada The recent developments of triphosphenium cations (1),[1] have focused on their convenient synthesis as opposed to their coordination chemistry.[2,3] This is surprising as they formally possess two lone pairs of electrons and are isoelectronic to the carbodiphosphorane, a compound well known to be a strong ligand. We have prepared and fully characterized a new class of zwitterionic Pn(I) (Pn = P, As) centers (2) utilizing the anionic bis(phosphino)borate ligand class developed by Peters et al.[4,5] Without the external counterion necessary for traditional triphosphenium cations, 2P has shown increased solubility in nonpolar solvents and enhanced Lewis basic behaviour when compared to 1. The unique coordination to gold (3) and rhodium (4) as well as calculations on these complexes will be discussed.

[1] A. Schmidpeter, S. Lochschmidt, W.S. Sheldrick, Angew. Chem. Int. Ed. 1982, 21, 63. [2] B.D. Ellis, M. Carlesimo, C.L.B. Macdonald, Chem. Commun. 2003, 1946. [3] E.L. Norton, K.L.S. Szekely, J.W. Dube, P.G. Bomben, C.L.B. Macdonald, Inorg. Chem. 2008, 47,

1196. [4] J.C. Thomas, J.C. Peters, J. Am. Chem. Soc. 2001, 123, 5100. 5) J.C. Thomas, J.C. Peters, Inorg.

Chem. 2003, 42, 5055.

Poster 33

IRIS-13 Victoria

121

Stannylphosphonium Salts E. P. MacDonald,a L. Doyle,a S. Chitnis,b N. Burford,b* U. Werner-Zwanzigera and A. Deckenc

(lizmac@dal.ca)

a Department of Chemistry, Dalhousie University, Halifax, NS, B3H 4J3, Canada b Department of Chemistry, University of Victoria, Victoria, BC, V8W 3V6, Canada

c Department of Chemistry, University of New Brunswick, Fredericton, NB, E3A 6E2, Canada The first examples of stannylphosphonium salts have been prepared as coordination complexes of stannylium cations with phosphine ligands. Synthetic procedures involve activation of a Sn_Cl bond by chloride ion abstraction promote donation from the phosphine, and by virtue of the cationic charge the Sn_P interaction is enhanced. Examples of complexes include tin centers that adopt, tetracoordinate and pentacoordinate geometries, and cations can be mono or dicationic.

Stannylphosphonium (I and II) and stannyldiphosphonium cations (III and IV).

[1] MacDonald, E.; Doyle, L.; Burford, N.; Werner-Zwanziger, U.; Decken, A. Angew. Chem. Int. Ed., 2011, 50, 11474-11477.

Poster 34

IRIS-13 Victoria

122

Functionalized Tin-Sulfur Clusters: Synthesis, Characterization and Investigations of the Formation Pathway

Jens P. Eußner and Stefanie Dehnen

(jens.eussner@chemie.uni-marburg.de) Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße,

D-35043 Marburg, Germany

Organic-inorganic hybrid materials attract attention in current research for a variety of different reasons. Inorganic building units linked by organic substituents show very interesting chemical and physical properties, that are different from those of the single components alone − well known from metal-organic frameworks. Organic decorated clusters (RT)xEy (T = Si, Ge, Sn; E = O, S, Se, Te) represent the basic building units, aiming at the extension into even more versatile multinary clusters as inorganic nodes, potential applications and hybrid networks. Recent work of our group describe the synthesis, characterization and derivatization of various binary clusters with functionalized ligands R, terminated by reactive groups like C=O or COOH.[1−3] According to Scheme 1, an organotin-trihalide furnishs the desired functionality of the clusters. To synthesize novel clusters with different functional groups, and to establish a library of according clusters, we generated organotetrel-trichlorides with alkene, alkyne and acid anhydride functional groups. These are to be transferred into the corresponding binary and multinary clusters, with a preliminary focus on T = Sn and E = S. Besides their chemical and physical properties, the formation and dynamics of functionalized clusters in solution is of interest.[4] By application of different reactants and reaction conditions, several intermediates could be observed and isolated. Based on this, we can propose the following route of condensation (Scheme 2).

Scheme 1: Synthetic route into functionalized chalcogenidometallate clusters (RF = functional organic substituent; Rx = functional molecule with complementary reactivity; T = Ge, Sn; X = Cl, Br, I; E = S, Se, Te; A = alkali metal, E = S, Se, Te, TMS).

Scheme 2: Proposed formation pathway from an organotintrichloride through several intermediates to an according organotinsulfide cluster.

[1] Z. Hassanzadeh Fard, L. Xiong, C. Muller, M. Holynska, S. Dehnen, Chem. Eur. J. 2009, 15, 6595-6604. [2] Z. Hassanzadeh Fard, R. Clerac, S. Dehnen, Chem. Eur. J. 2010, 16, 2050-2053. [3] Z. Hassanzadeh Fard, M. R. Halvagar, S. Dehnen, J. Am. Chem. Soc. 2010, 132, 2845-2849. [4] M. Bouška, L. Dostál, Z. Padělková, A. Lyčka, S. Herres-Pawlis, K. Jurkschat, R. Jambor, Angew. Chem. 2012, 124, 3535-3540.

Poster 35

IRIS-13 Victoria

123

Silver(I) Coordination Complexes: Controlling Self-assembly in the Construction of Supramolecular Networks

Fergus R. Knight, Rebecca A. M. Randall, Lucy Wakefield, Alexandra M. Z. Slawin and J. Derek

Woollins (frk@st-andrews.ac.uk)

EaStCHEM, School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, U.K Coordination chemistry is an integral feature of inorganic and bioinorganic chemistry, with many applications in polymer design and materials science. In recent times, the metal-ligand interaction has emerged as an important tool for the manufacture of supramolecular metal complexes and is prominent in the design of organic solids and metal-organic frameworks (MOFs). Crystal engineering utilises the metal-ligand coordination bond to construct coordination networks, generally through the self-assembly of tuneable building blocks. Bridging organic ligands acting as rigid supports are linked in an ordered lattice, building extended and often multidimensional networks with central metal ions. Self-assembly, which dictates the structural motif of the final complex is controlled by experimental conditions. Factors such as the central metal ion oxidation state, the coordination geometry, the metal-to-ligand ratio, the nature and spacer length of the bridging ligand, the presence of solvents and the type of counter-anions, all play a significant role. Silver has become a fashionable building block for connecting organic ligands in supramolecular networks. The series of chalcogen-donor ligands Acenap[EPh][E`Ph] (Acenap = acenaphthene-5,6-diyl; E/E` = S, Se, Te)1 coupled with silver(I) salts provide ideal building blocks for constructing coordination networks due to the diversity of the silver coordination geometry and the contrasting donor functionalities of the rigid acenaphthene supports. Acenaphthene derivatives [Acenap(EPh)(E`Ph)] (Acenap = acenaphthene-5,6-diyl; E/E` = S, Se, Te)[1] were each independently treated with silver tetrafluoroborate [AgBF4] and silver trifluoromethanesulfonate [AgOTf]. The coordinating ability of the counter-anions, the type of donor atoms available to the silver(I) metal centre and the nature of the solvents used during the reaction and recrystallisation stages have a dramatic effect on the final solid state structure and leads to the formation of unusual coordination architectures; 3D supramolecular metal-organic frameworks, 1D extended helical chain polymers, mononuclear, monomeric, silver(I) sandwich complexes, three-coordinate monomeric, silver(I) complexes.[2]

[1] L. K. Aschenbach, F. R. Knight, R. A. M. Randall, D. B. Cordes, A. Baggott, M. Bühl, A. M. Z.

Slawin and J. D. Woollins, Dalton Trans., 2012, 41, 3141. [2] F. R. Knight, R. A. M. Randall, L. Wakefield, A. M. Z. Slawin and J. D. Woollins, Chem. Eur. J.,

submitted.

Poster 36

IRIS-13 Victoria

124

Synthesis and Characterization of Chalcogenophosphonium Cations

S.H. Lucas and N. Burford (shlucas@uvic.ca)

Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada The Burford group has developed synthetic procedures to phosphinophosphonium[1], pnictinopnictonium[2,3], and stannylphosphonium cations[4]. An extension of this previous work involves the group 16 elements (the chalcogens, Ch), with the intention of applying high yield synthetic approaches to Ch-P bond formation giving thio, seleno, and tellurophosphonium cations. Through the use of chalcogen halides, and halide abstracting agents, chalcogen cations are generated in situ (Figure 1a), which then react with phosphines to form chalcohenophosphonium cations (Figure 1b). The chalcohenophosphonium cations are characterized using 31P{1H}, 1H, 13C{1H}, 77Se{1H}, and 125Te{1H} NMR spectroscopy and X-ray crystallography.

ChR X + ABS ChR + ABSX-

ChR + ABSX-+PR'3 ChR

+PR'3+ ABSX

-

a

b

H+

H+

Figure 1: Proposed synthetic approach for the formation of chalcohenophosphonium cations. a) Halide

abstraction of RChX. b) Formation of chalcohenophosphonium cation. R, R′ = Alkyl, Aryl, ABS = Halide abstraction agent, X= F, Cl, Br

[1] Dyker and Burford., Chem. Asian J., 2008, 3, 28. [2] Conrad, Burford, et al., J. Am. Chem. Soc., 2009, 131, 5066. [3] Chitnis, Peters, et al., Chem. Commun., 2011, 47, 12331. [4] Macdonald, Doyle, et al., Angew. Chem. Int. Ed., 2011, 50, 11474.

Poster 37

IRIS-13 Victoria

125

Ge(I)-Ge(I) as a Building Unit to Construct Oligomeric Germanes

Hsien-Chen Yu, Fan-Shan Yang and Yi-Chou Tsai (yictsai@mx.nthu.edu.tw)

Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan 30013 Stabilized by sterically hindered ligands, the univalent germanium dimers of the type RGeGeR have been recognized, and they all exist in a trans-bent conformation.[1-3] Notably, the Ge(I)–Ge(I) bond order is in the range of 1-3. Herein, we report the employment of a terdentate 2,6-diamidopyridyl ligand to stabilize a Ge2

2+ motif and give an unprecedented cis-bent complex. The separation of the single bonded Ge–Ge is 2.5168(6) Å. This dimeric germanium(I) species turns out to be a good synthon for the preparation of oligomeric germanes. For example, linear mixed-valent homotetranuclear GeI

2GeII2 and mixed-valent

heterotetranuclear GeI2SnII

2 and GeI2ZnII

2 complexes can be prepared via salt metathesis. Furthermore, a bent trinuclear GeIIGeIII

2 and cyclic homo-divalent tetranuclear and pentanuclear germanes can also be prepared through redox reactions.

[1] Stender, M.; Phillips, A. D.; Wright, R. J.; Power, P. P. Angew. Chem., Int. Ed. 2002, 41, 1785. [2] Sugijama, Y.; Sasamori, T.; Hosoi, Y.; Furukawa, Y.; Takagi, N.; Nagase, S.; Tokitoh, N. J. Am.

Chem. Soc. 2006, 128, 1023. [3] Green, S. P.; Jones, C.; Junk, P. C.; Lippert, K.-A.; Stasch, A. Chem. Commun. 2006, 3978.

Poster 38

IRIS-13 Victoria

126

Synthesis and Structures of Titanastannene Coordinated by a Stannylene and Ti2Sn4 Ring Compound

Takuya Kuwabara,a Masaichi Saito,a Jing Dong Guob and Shigeru Nagaseb

(s11ds003@mail.saitama-u.ac.jp) aDepartment of Chemistry, Graduate School of Science and Engineering, Saitama University, Shimo-

okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan bFukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho, Sakyou-ku,

Kyoto, 606-8103, Japan Heavier congeners of the cyclopentadienyl anion have received much attention in view of their aromaticity.[1] Our group has succeeded in the synthesis of dilithio-stannole[2] and –plumbole[3] and concluded that they have considerable aromatic character, based on the X-ray analyses, NMR studies and theoretical calculations. We next investigate the reactions of dilithiostannole with various metal reagents to obtain stannole complexes Reactions of dilithiostannole 1[4] with Cp2TiCl2 followed by recrystallization provided two different crystals, one of which is dark purple and diamagnetic, and the other of which is dark red and paramagnetic. X-ray diffraction analysis revealed that the products are titanastannene complex 2 and compound 3 bearing a Ti2Sn4 six-membered ring with sandwich structures. The TiSn bond lengths in 2 are 2.6860(17) and 2.7255(18) Å, which are much shorter than those in 3 (2.9080(11), 2.9245(10) Å) and the TiSn bond lengths ever reported (2.8422.984 Å). In the 119Sn NMR of 2, a sharp signal was observed at 1332.5 ppm, which indicates that the tin atoms have stannylene character. Theoretical calculations revealed that the TiSn bond is a double bond consisting of -donation of a stannylene moiety to the Ti center and back-donation from d(Ti) to p(Sn). Interestingly, a unique interaction between the two p orbitals on the tin atoms is also found.

[1] For example of recent reviews, see: (a) Saito, M.; Yoshioka, M. Coord. Chem. Rev. 2005, 249, 765.

(b) Lee, V. Y.; Sekiguchi, A. Angew. Chem., Int. Ed. 2007, 46, 6596. (c) Lee, V. Y.; Sekiguchi, A. In Organometallic Compounds of Low-coordinate Si, Ge, Sn and Pb, Wiley, Chichester, p335. (d) Saito, M. Coord. Chem. Rev. 2012, 256, 627.

[2] Saito, M.; Haga, R.; Yoshioka, M.; Ishimura, K.; Nagase, S. Angew. Chem., Int. Ed. 2005, 44, 6553. [3] Saito, M.; Sakaguchi, M.; Tajima, T.; Ishimura, K.; Nagase, S.; Hada, M. Science 2010, 328, 339. [4] Saito, M.; Kuwabara, T.; Kambayashi, C.; Yoshioka, M.; Ishimura, K. Nagase, S. Chem. Lett. 2010,

39, 700.

Li Li

2

Sn

Sn

TiCp

CpSn

Sn

Ti

Cp

Cp

Sn

Sn

Ti

Cp

Cp

3

Sn

Et

Et EtLi(Et2O)

EtLi1

Poster 39

IRIS-13 Victoria

127

Weak Te,Te Bonding Through the Looking Glass of NMR Spin-Spin Coupling

Michael Bühl,a Fergus Knight,a Anezka Krístková,b Olga L. Malkinab and J. Derek Woollinsa (jdw3@st-andrews.ac.uk)

aEaStCHEM School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9ST, UK

bSlovak Academy of Sciences, Institute of Inorganic Chemistry, SK-84536 Bratislava, Slovakia NMR spin-spin coupling between two nuclei can be a probe for the chemical bonding between them. The "through-space" coupling between formally nonbonded atoms can be assessed computationally.[1] Pnictogen and chalgocen substituents, placed in peripositions on a naphthalene scaffold (Chart I), show onset of multicentre bonding.[2] To explore possible relationships between these two aspects, we now report a joint DFT and experimental study of J(Te,Te) couplings in peri-napthalene ditellurides.

Chart I

Huge "across-the bay" Te,Te couplings in the kHz range have been predicted computationally at appropriate levels of DFT (ZORA-SO), and have been confirmed experimentally for N1 and A1. These couplings turn out to be strongly dependent on the molecular conformation and can be related to the spatial overlap of lone-pair orbitals (assessed through the coupling deformation density pathway[1]) and the onset of multicentre bonding (through natural bond orbital analysis). J(Te,Te) couplings can thus be a sensitive probe ("looking glass") into electronic and geometrical structure of ditellurides.

[1] O. L. Malkina, A. Kristkova, E. Malkin, S. Komorovsky, V. G. Malkin, Phys. Chem. Chem. Phys. 2011, 13, 16015.

[2] L. K. Aschenbach, F. R. Knight, R. A. M. Randall, D. B. Cordes, A. Baggott, M. Bühl, A. M. Z. Slawin, J. D. Woollins, Dalton Trans. 2012, 41, 3141.

Poster 40

IRIS-13 Victoria

128

Mono- and Binuclear Organoindium Thiolate Complexes and their Reactivity as Catalysts in Lactone Polymerization

Glen G. Brianda, Jessica D. Marksa, Ryan G. Warehama, Andreas Deckenb, Laura E.N. Allenc and

Michael P. Shaverc

(gbriand@mta.ca) aDepartment of Chemistry and Biochemistry, Mount Allison University, Sackville NB Canada

bDepartment of Chemistry, University of New Brunswick, Fredericton, NB Canada cDepartment of Chemistry, University of Prince Edward Island, Charlottetown, PE Canada

Polylactides have been identified as possible candidates as alternative biodegradable and bio-renewable polymers (plastics) with specialized applications in the pharmaceutical and microelectronics industries (Dove et al. Chem. Soc. Rev. 2010, ). Ring opening polymerization (ROP) has been found to be a superior method for the preparation of these materials in that it allows for a greater degree of control over the molecular parameters of the resulting polymer, including lower polydispersities, higher molecular weights and higher end group fidelity. Recently, some compounds of indium have been shown to facilitate the ROP of both rac-lactide (Mehrkhodavandi et al. Angew. Chem., 2008; Tolman et al., J. Am. Chem. Soc., 2010) and ε-caprolactone (Huang et al. Inorg. Chim. Acta, 2006), though there have been very few studies in this area. Indium based catalysts are attractive due to their new reactivity profile, low toxicity and stability in water. In this context, we have prepared a series of methylbis(thiolato)indium compounds containing bifunctional ester-, amine- and ether-thiolate ligands which exhibit mono- or binuclear structures. Their syntheses, structures and reactivity as ROP catalysts toward cyclic lactones will be discussed.

Poster 41

IRIS-13 Victoria

129

Synthesis of Selenium- and Tellurium-Containing Aminosilane Ligands

Jamie S. Ritch (j.ritch@uwinnipeg.ca)

Department of Chemistry, The University of Winnipeg, 515 Portage Avenue, Winnipeg, MB R3B 2E9 Canada

Materials featuring selenium or tellurium are of great contemporary interest as components in advanced electronic devices. Commercial examples include low-cost solar cells (CdTe),[1] and fast response IR detectors (PbSe).[2] While p-block and late d-block chalcogenides are generally well-studied,[3] there exists a great potential for development of novel Se- and Te-containing materials of the early and mid d-block elements. A new class of heavy chalcogen-containing ligand, 1, is being developed to enable the synthesis of CVD precursors to transition metal selenides and tellurides. This contribution will discuss the preparation of aminosilane ligands 1, and some preliminary studies of their coordination chemistry towards transition metals.

[1] First Solar website. http://www.firstsolar.com/en/Innovation/CdTe-Technology (accessed June 13, 2012).

[2] Hamamatsu Photonics website. http://jp.hamamatsu.com/products/sensor-ssd/pd128/pd134/ index_en.html (accessed June 13, 2012).

[3] See, for example: (a) Dey, S.; Jain, V. K. Platinum Metals Rev. 2004, 48, 16-29; (b) Bochmann, Chem. Vap. Deposition 1996, 2, 85-96.

Poster 42

IRIS-13 Victoria

130

Borane Catalyzed Post-polymerization Modification of Polysilanes

Peter T. K. Lee, Miranda K. Skjel and Lisa Rosenberg (peterlee@uvic.ca)

Department of Chemistry, University of Victoria, P.O. Box 3065, Stn CSC Victoria, BC, V8W 3V6, Canada

We previously reported the borane-catalysed chemoselective Si-H activation to make new Si-S containing oligosilanes.[1] We report here the catalytic post-polymerization modification of poly(phenylsilylene) by hydrosilation and heterodehydrocoupling reactions with thioketone and thiols, respectively, catalysed by B(C6F5)3. Three new random copolymers with up to 40% -SR sidechain incorporation were isolated and characterized by 1H/13C/29Si NMR, IR, GPC, UV-Vis, and elemental analysis. Importantly, the borane catalyst is chemoselective for Si-H activation over Si-Si bond cleavage: no small molecular weight oligosilanes were detected by GC/MS or 1H NMR, and an increase in molecular weight from the starting poly(phenylsilylene) to S-substituted polysilane was determined by light scattering GPC. These results along with recent efforts to extend the post-polymerization modification method to other organic substrates, such as chelating sidechains to make Si• radical recombination competitive with Si-Si chain scission, will be presented.

ppm-10 -20 -30 -40 -50 -60 -70

H-Si-S polymer endcaps

PhSiH

PhSiHSSiPh

n

p-C6H4CH3

SiH

Phm

HSiPh n'5 mol % B(C6F5)3

HS-p-C6H4CH3-H2

C6D6J=188 Hz

29Si: 99 MHz1H: 500 MHz

DEPT90

Figure: 29Si DEPT NMR of Starting and S-modified Poly(phenylsilylene) [1] Harrison, D. J.; Edwards, D. R.; McDonald, R.; Rosenberg, L. Dalton Trans. 2008, 3401

Poster 43

IRIS-13 Victoria

131

Networking of Semiconductor Clusters by Non-metal Linkage or Transition Metal Coordination

Beatrix Barth and Stefanie Dehnen (barthb@students.uni-marburg.de)

Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße, D-35043 Marburg, Germany

In the last decade, the design of metal-organic frameworks (MOFs) has attracted considerable attention in supramolecular and materials chemistry due to their enormous variety of interesting structural topologies and wide potential applications as functional materials.[1] In spite of the known and outstanding characteristics of chalcogenidometallate phases, the synthesis of chalcogenidometallate-organic frameworks is not studied extensively so far.[2] Our group recently investigated the synthesis and reactivity of new ω-carbonyl-functionalized thiostannate clusters of the general type [(R1Sn)4(µ-S)6] (with R1 = CMe2CH2COMe in 1)[3] that possess good prerequisites to form chalcogenido-MOFs. The functionalized Sn/S cages not only enable an approach to a new class of hybrid materials; they also exhibit a suitable reactivity for non-metal linkage via hydrazine-functionalized organic units, such as realized at the synthesis of 2 (Scheme 1).[4]

1 2

Scheme 1: Synthesis of compound 2, consisting of [Sn6S10] units that are linked by 1,5-bis[(E)-2-

(4-methylpentan-2-ylidene)hydrazinyl]naphthalene organic spacers.

Consequently, there is a high interest in the further development of the synthetic pathways to interconnect these clusters not only by bis-, but also via tris- and tetra-functionalized organic units, such as hydrazine-functionalized adamantanes. Another approach towards networks with chalcogenidometallate cages as nodes is accessible by choosing R1 as a chelating ligand to form according clusters like 3. After cluster formation, the network will be formed by transition metal coordination. Precursors to these pathways have been synthesized. As an alternative, the metals can be incorporated in the metallate cages, such as observed at a reaction of 3 with Zn2+, thus producing new ternary systems like 4 that still provide donor-ligands for further metal coordination.[5]

1 3 4 Scheme 2: Introduction of a bidentate ligand and coordination and insertion of ZnX2 (X = Cl, Br, I) into 3.

[1] J. L. C. Rowsell, O. M. Yaghi, Microp. Mesop. Mat. 2004, 73, 3. [2] S. Dehnen, M. Melullis, Coord. Chem. Rev. 2007, 251, 1259; X. Bu, N. Zheng, P. Feng, Chem. Eur. J. 2004, 10, 3356. [3] Z. H. Fard, L. Xiong, C. Müller, M. Holynska, S. Dehnen, Chem. Eur. J. 2009, 15, 6595. [4] Z. H. Fard, M. R. Halvagar, S. Dehnen, J. Am. Chem. Soc. 2010, 132, 2848. [5] B. Barth, E. ter Jung, S. Dehnen, in preparation.

Poster 44

IRIS-13 Victoria

132

Investigation of Redox Potentials of the Three-dimensional Aromatic Carborate Anions [1-R-CB11X5Y6]- (R = H, Me; X = H, Me, Hal, Y = H, Hal)

Christoph Bollia, Carsten Knappa, René T. Boeréb, Maik Finzec, Alexander Himmelspachc and Tracey L.

Roemmeleb (cbolli@uni-wuppertal.de)

aFachbereich C - Anorganische Chemie, Bergische Universität Wuppertal Gaußstraße 20, 42119 Wuppertal, Germany

bUniversity of Lethbridge cUniversität Würzburg

Halogenated 1-carba-closo-dodecaborate anions are three-dimensional aromatic clusters which were widely used as weakly coordinating anions. (WCAs).[1-6] The weakly coordinating nature of these anions allows to stabilize the highly reactive fullerene cation, [C60]+,[7] and the first free silylium cation, [Mes3Si]+.[8] Their high resistance to oxidation is demonstrated by the successful preparation of salts containing strong oxidizers such as oxidized hexabromophenylcarbazole[7] and [NO]+.[9]

In this contribution, we report the first systematic experimental and theoretical study on the oxidation and reduction of 1-carba-closo-dodecaborate anions. The gas-phase ionization enthalpies and the electron affinities for the parent [1-H-CB11H11]-, the undecahalogenated derivates [1-H-CB11X11]- (X = F, Cl, Br and I), the hexabrominated anions [1-H-CB11H5Br6]- and [1-H-CB11Me5Br6]- as well as for the C-methylated, undecabrominated anion [1-Me-CB11Br11]- were assessed by quantum-chemical calculations. Therefore, full geometry optimizations of each anion along with the neutral and dianionic radicals were undertaken at the PBE0/def2-TZVPP level of theory. The electrochemical oxidation or reduction, respectively, of these anions in SO2 and CH3CN was investigated by square wave and cyclic voltammetry.

[1] I. Krossing, I. Raabe, Angew. Chem. Int. Ed. 2004, 43, 2066-2090; Angew. Chem. 2004, 116, 2116-

2142; [2] S. H. Strauss, Chem. Rev. 1993, 93, 927-942; [3] K. Seppelt, Angew. Chem. Int. Ed. 1993, 32, 1025-1027; Angew. Chem. 1993, 105, 1074-1076; [4] S. Körbe, P. J. Schreiber, J. Michl, Chem. Rev. 2006, 106, 5208-5249 [5] C. A. Reed, Acc. Chem. Res. 2010, 43, 121-128; [6] C. Knapp, Comprehensive Inorganic Chemistry II, 2012, Vol. 1, Chapter 1.25, in press. [7] C. A. Reed, K.-C. Kim, R. D. Bolskar, L. J. Mueller, Science, 2000, 289, 101-104; [8] K.-C. Kim, C. A. Reed, D. W. Elliott, L. J. Mueller, F. Tham, L. Lin, J. B. Lambert, Science, 2002,

297, 825-827; [9] C. Bolli, C. Knapp, T. Köchner, Z. Allg. Anorg. Chem. 2012, 638, 559-564.

Figure 4: CV (A) ( = 0.2 V s−1

) and SWV (B) of 1.9 mM [nBu4N][1-H-CB11F11] with 1.9 mM Fc in

CH3CN at 202 °C.

Poster 45

IRIS-13 Victoria

133

Fig. 1. Part of the crystal structure of [Na(SO2)6]B12Br12[B12Br12]

The Oxidation of Perhalogenated Boron Clusters [B12X12]2- (X = F, Cl, Br)

Mathias Keßler and Carsten Knapp (mkessler@uni-wuppertal.de)

Fachbereich C – Anorganische Chemie, Bergische Universität Wuppertal, Gaußstr. 20, 42119 Wuppertal, Germany

Deltahedral closo-borane dianions [BnHn]2- feature a special binding situation which can be well understood by MO theory.[1] The perhalogenated closo-dodecaborates [B12X12]2- (X = F, Cl, Br, I) stand out due to their exceptional stability resulting from their strong halogen-boron bonds. The oxidation of the closo-dodecaborates [B12R12]2- (R = Me, alkoxy, aryloxy, hydroxy) and the structural characterization of the corresponding radical anions and the neutral hypercloso clusters could be accomplished up to now. [2-4] Oxidation of the perhalogenated closo-dodecaborates [B12X12]2- (X = F, Cl, Br) is a challenging task due to the electron withdrawing effect of the halogens. However the replacement of conventional organic solvents by liquid sulfur dioxide and the usage of oxidation agents like arsenic pentafluoride allows the oxidation and the characterization of the radical [B12Cl12]·- and neutral B12Cl12.[5] The oxidation of the perhalogenated closo-dodecaborates [B12X12]2- (X = F, Cl, Br) and the characterization of the resulting radical anions [B12F12]·-, [B12Cl12]·- and [B12Br12]·- and the hypercloso clusters B12Cl12 and B12Br12 will be presented.

[1] M. A. Fox, K. Wade, Pure Appl. Chem. 2003, 1315. [2] T. Peymann, C. B. Knobler, M. F. Hawthorne, Chem. Commun. 1999, 2039. [3] a) T. Peymann, C. B. Knobler, S. I. Khan, M. F. Hawthorne, Angew. Chem. Int. Ed. 2001, 40, 1664 b)

O. K. Farha, R. L. Julius, M. W. Lee, R. H. Huertas, C. B. Knobler, M. F. Hawthorne, J. Am. Chem. Soc. 2005, 127, 18243 c) M. W. Lee, O. K. Farha, M. F. Hawthorne, C. H. Hansch, Angew. Chem. Int. Ed. 2007, 46, 3018

[4] N.-D. Van, I. Tiritiris, R. F. Winter, B. Sarkar, P. Singh, C. Duboc, A. Muñoz-Castro, R. Arratia-Pérez, W. Kaim, T. Schleid, Chem. Eur. J. 2010, 16, 11242.

[5] R. T. Boeré, S. Kacprzak, M. Keßler, C. Knapp, R. Riebau, S. Riedel, T. L. Roemmele, M. Rühle, H. Scherer, S. Weber, Angew. Chem. Int. Ed. 2011, 50, 549.

Poster 46

IRIS-13 Victoria

134

Heavy p-Block Analogues of Thiazyl Radicals

Thao T. P. Tran and Jeremy M. Rawson (tran1y@uwindsor.ca, jmrawson@uwindsor.ca)

Department of Chemistry and Biochemistry, University of Windsor, 273-1 Essex Hall, 401 Sunset Avenue, Windsor, ON Canada N9B 3P4, Canada

The physical properties of dithiazolyl radicals (A) have attracted considerable interest as magnetic and spin-switching devices [1]. We report here recent investigations into phosphorus-containing heterocycles with a view to generating the isoelectronic phosphorus radicals (B). Reaction of benzene or toluenedithiol with PCl3 using a modification of the literature method [2] affords the corresponding heterocycles C (R = H, Me). The reactivity of the chloride derivatives C is discussed including their reduction with elemental sodium to form the P-P -bonded dimer D and their Lewis acid character in reaction with AlCl3/GaCl3 to afford phosphenium-phosphine/arsine complexes F [3]. Oxidation of D with X2 (X = Br and I) occurs with P-P bond cleavage.

[1] A. Alberola, J.M. Rawson and A.L. Whalley, J. Mater. Chem., 2006, 16, 2560. [2] M. Baudler, A. Moog, K. Glinka, U. Kelsch, Z. Naturforsch., Teil B, 1973, 28, 363. [3] N. Burford, P. J. Ragogna, J. Chem. Soc., Dalton Trans., 2002, 4307–4315.

Poster 47

IRIS-13 Victoria

135

Brønsted Acids Containing Hexacoordinated Phosphorus Anions

Khatera Hazin, Paul W. Siu and Derek P. Gates (dgates@chem.ubc.ca)

Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T 1Z1, Canada

The development of solid, weighable Brønsted acids is of particular interest due to their potential use in bond activation reactions.[1] However, systems of the type H+[X]- are not generally isolable due to the inherent high reactivity of most anions with H+. The successful isolation of a Brønsted acid requires a weakly coordinating anion (WCA). For example, WCAs such as [B(C6F5)4]- and [Al{OC(CF3)3}4]-

have successfully been employed to obtain isolable solid Brønsted acids. We have been interested in employing the known phosphorus (V) anion [1]- [2] as a charge balancing anion to afford isolable Brønsted acids. The synthesis and characterization of the solid, weighable HL2[1] (Figure 1, L = donor solvent) will be discussed in this presentation.[3] In addition, the reactivity and potential applications of HL2[1] will be surveyed.

Figure 1: Hexacoordinated phosphorus (V) framework HL2[1]. [1] I. Krossing, I. Raabe, Angew. Chem. Int. Ed. Engl. 2004, 43, 2066-2090. [2] J. Lacour, C. Ginglinger, C. Grivet, G. Bernardinelli, Angew. Chem. Int. Ed. Engl. 1997, 36, 608-610. [3] (a) P. W. Siu, D.P. Gates, Organometallics, 2009, 28, 4491-4499; (b) P.W. Siu, D.P. Gates, Can. J. Chem. 2012, In Press.

Poster 48

IRIS-13 Victoria

136

Improved N-Heterocyclic Carbenes and Its Metal Complexes.

Jan Turek1, Illia Panov2, Zdeňka Padělková1 and Aleš Růžička1

(jan.turek@upce.cz)

1 Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, Pardubice 532 10, Czech Republic

2 Institute of Organic Chemistry and Technology, Faculty of Chemical Technology, University of Pardubice, Studentska 573, Pardubice 532 10, Czech Republic

N-heterocyclic carbenes (NHCs) have been known since the late 1960s when the pioneering work of Öfele and Wanzlick[1, 2] was published. But the real breakthrough in this field of chemistry came nearly thirty years later with the work ‘’A Stable Crystalline Carbene’’ published by Arduengo in 1991[3]. NHCs have attracted worldwide attention not only because of their excellent bonding properties (coordination to various elements across the whole periodic system) but also because of their possible use as catalytically active ligands[4] comparable with cyclopentadienyls and phosphines. The main goals of the presented work were the synthesis of a set of new hybrid N-heteroleptic carbenes, among which one has an extra coordinating functional group, as well as their complexes with various metals. Afterwards, selected palladium complexes were tested for their possible catalytic activity.

Fig. 1 Molecular structure of one of the studied compounds (Hydrogen atoms are omitted for clarity). The Science Foundation of Czech Republic is gratefully acknowledged for the financial support (Project no. P207/12/0223) [1] K. Öfele J. Organomet. Chem. 1968, 12, P42. [2] H. W. Wanzlick, H.-J. Schönherr Angew. Chem.Int. Ed. Engl. 1968, 7, 141. [3] A. J. Arduengo, R. L. Harlow, M. Kline J. Am. Chem. Soc. 1991, 113, 361. [4] D. Enders, O. Niemeier, A. Henseler, Chem. Rev. 2007, 107, 5606.

Poster 49

IRIS-13 Victoria

137

Theoretical Investigation of S2N2 Polymerization Employing Solid State Molecular Dynamics Simulations

Teemu T. Takaluoma†, Kari Laasonen‡ and Risto S. Laitinen†

(teemu.takaluoma@oulu.fi)

† Department of Chemistry, University of Oulu, P.O Box 3000, FIN-90014, University of Oulu, Finland ‡ Department of Chemistry, Aalto University, P.O Box 16100, FIN-00076 Aalto, Finland

(SN)x is a unique metallic polymer with superconducting properties at low temperatures (Tc < 0.3 K).[1,2] The classical synthetic route to produce the crystalline polymer goes through spontaneous topotactical polymerization of S2N2 ring molecules.[1,3,4] The topotactical polymerization reaction of crystalline S2N2 to (SN)x has been investigated with quantum mechanical solid state molecular dynamics simulations for the first time. Simulations have been performed using a simulation cell (17.94 Å, 15.07 Å, 16.99 Å) composing of 64 S2N2 molecules. The polymerization of S2N2 is a very slow reaction and usually takes hours to reach completion at RT. Such timescales are beyond conventional MD approaches, where the usual simulation time limits are measured in pico- or nanoseconds. Practical simulation timescales are achieved by compression of the crystalline ring material with high isotropic pressure of 50 GPa (and at 600 K). When the ring polymerization is initiated, the whole system undergoes a very rapid reaction to a fully polymerized crystalline material. Polymerization takes place in direction of the crystallographic a axis. The rings undergo single-bond cleavage and react along row of rings in ac-plane. Metastable side reactions are observed in the direction of b and c axes. Out-of-plane ring opening is also observed as a possible pathway. Towards the end of the reaction, the metastable species dissociate and in the final product only polymers in direction of a axis remain.

Figure 1: Progress of polymerization at 0 %, 25 % and 100 % of completion. (revPBE/DZVP-MOLOPT-SR with CP2K) [1] Chivers, T.; Laitinen, R. S. In Handbook of Chalcogen Chemistry: New Perspectives in Sulfur,

Selenium and Tellurium; Devillanova, F. A., Ed.; Royal Society of Chemistry Publishing: Cambridge, U.K., 2007; p 223.

[2] Greene, R. L.; Street, G. B.; Suter, L. J. Phys Rev. Lett. 1975, 34, 577. [3] Labes, M. M.; Love, P.; Nichols, L. F. Chem. Rev. 1979, 79, 1. [4] Cohen, M. J.; Garito, A. F.; Heeger, A. J.; MacDiarmid, A. G.; Mikulski, C. M.; Saran, M. S.;

Kleppinger, J. J. Am. Chem. Soc. 1976, 98, 3844.

Poster 50

IRIS-13 Victoria

138

Six Membered N,N-Diazastanna Cycles Based On Β-Diketiminate Complexes

Roman Olejnik, Zdenka Padelkova and Ales Ruzicka (roman.olejnik@email.cz)

Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, CZ-532 10, Pardubice, Czech Republic

β-Diketiminates (BDI) play important role in organic and organometallic chemistry. Bifunctional BDI contain appropriate functional groups which can extra coordinate metal centre and it can affect higher stability of final metal complexes. These metal-containing species can be used in many areas of chemistry[1]. Divalent tin complexes were used for carbon dioxide activation[2] or as initiators for polymerization of rac-lactide[3]. Ligands can be prepared generally from 1,3-diones and primary aromatic amines[4]. We are interested in BDI ligand, which is prepared from acetylacetone and o-anisidine (LCOH) because of donor groups in convenient positions. This type of ligand forms six-membered diazametalla rings by transmetallation reaction of lithium complexes with metal chlorides (M = Sn, Ge, Bi) or direct synthesis from LCOH BDI and metal amides (M = Sn, Nd, La, Sm). Prepared heterocyclic tin(II) complexes were further tested especially in terms of reactivity with organic substrates. All prepared compounds were characterized by multinuclear NMR spectroscopy and when it was possible by XRD techniques.

Figure. The molecular structure of one of compounds studied. Authors would like to thank the Czech Science Foundation (grant no. 104/09/0829) for financial support. [1] M. H. Chisholm, J. C. Gallucci and K. Phomphrai; Inorg. Chem. 2005, 44, 8004. [2] L. Ferro, P. B. Hitchcock, M. P. Coles, H. Cox and J. R. Fulton; Inorg. Chem. 2011, 50, 1879. [3] A. P. Dove, V. C. Gibbon, E. L. Marshall, H. Rzepa, A. J. P. White, D. J. J. Williams; J. Am. Chem.

Soc. 2006, 128, 9834. [4] R. Olejnik, Z. Padelkova, M. Horacek and A. Ruzicka; Main Group Met. Chem. 2012, 35, 13.

Nd1 Si1

Si2 Si3

Si4

C1

C2

C3 N1 N2

O1 O2

N3 N4

Poster 51

IRIS-13 Victoria

139

Structural Characterization of a [Pd3Cl9(μ3-Se6)]3- Anion Containing the Se6-ring

A. Eironen, R. Oilunkaniemi and R. S. Laitinen

(aino.eironen@oulu.fi) Department of Chemistry, P.O. Box 3000, FI-90014, University of Oulu, Finland

We have recently reported the structures of two palladium complexes [PdCl2{Se,Se′-Se4(NtBu)n}] (n = 3, 4) containing novel cyclic selenium imides.[1] These two complexes were isolated from the 1:2 reaction of [PdCl2(NCPh)2] with Se(NtBu)2 which was synthesized in situ by the reaction of SeCl4 with tBuNH2 in a molar ratio of 1:6. We have also studied the related complexation reaction of SeCl2 and tBuNH2 with [PdCl2(NCPh)2]. The reaction resulted in the formation of a new palladium complex, (tBuNH3)3[Pd3Cl9(μ3-Se6)], containing a neutral μ3-bridging cyclohexaselenium ligand coordinating to three PdCl3 fragments. There are only a few transition metal complexes containing the cyclohexaselenium ligand: [PdCl2(Se6)],[2] [PdBr2(Se6)],[2] [(AgI)2Se6)],[3] [Ag2(Se6)(SO2)2][Sb(OTeF5)6]2,[4] [Ag2(Se6)(SO2)4][Al(OC(CF3)3)4]2,[4] [Ag2(Se6)][AsF6]2,[4] [Ag(Se6)][Ag2(SbF6)3] [4]. [1] M. Risto, A. Eironen, E. Männistö, R. Oilunkaniemi, R. S. Laitinen, and T. Chivers, Dalton Trans.,

2009, 8473. [2] K. Neiniger, H. W. Rotter, and G. Thiele, Z. Anorg. Allg. Chem., 1996, 622, 1814. [3] H.-J. Deiseroth, M. Wagener, and E. Neumann, Eur. J. Inorg. Chem. 2004, 4755. [4] D. Aris, J. Beck, A. Decken, I. Dionne, J. Schmedt auf der Günne, W. Hoffbauer, T. Köchner, I.

Krossing, J. Passmore, E. Rivard, F. Steden, and X. Wang, Dalton Trans., 2011, 40, 5865.

Poster 52

IRIS-13 Victoria

140

N-Heterocyclic Carbene Borane-Containing -Conjugated Systems

Kazuhiko Nagura,a Shohei Saito,a Roland Fröhlich,b Frank Glorius,b and Shigehiro Yamaguchia

(yamaguchi@chem.nagoya-u.ac.jp)

aDepartment of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan, bOrganisch-Chemisches Institut, Westfälische Wilheims-Universität Münster, Corrensstrasse

40, 48149 Münster, Germany

N-Heterocyclic carbenes (NHCs) react with trivalent boranes to form Lewis base/acid complexes. Recently, the NHC-borane chemistry has attracted increasing attention because of their intriguing reactivity as the catalysts and reactants. In this work, we focus our attention on the NHC-boranes from a materials point of view. We designed and synthesized thiophene-based -conjugated systems 1–3 bearing NHC-borane moieties at the terminal positions.[1] The intramolecular coordination of the NHC to the boryl group fixes the NHC-thiophene skeleton in a coplanar fashion, ensuring the effective -conjugation with each other. In addition, the zwitterionic structure of the NHC-borane moiety endows the thiophene skeleton with highly polar and electron-donating characters. In the absorption spectra, the thiophene derivative 1a shows negative solvatochromism from max 349 nm in cyclohexane to max 327 nm in DMSO, which demonstrates the large dipole moment in the ground state. Notably, upon irradiation of a UV light to 1a under a nitrogen atmosphere, a photoreaction smoothly took place to form a borabicyclo[4.1.0]heptadiene skeleton with a drastic color change from colorless to deep yellow (max 429 nm). In contrast, the expanded bithiophene derivatives 2 and 3 were inert to this photoreaction. The cyclic voltammograms of 2 and 3 show low oxidation potentials at E1/2 = +0.28 V and Epc = +0.27 V, respectively, which indicate the NHC-borane moiety is a powerful unit to make the π skeleton electron-donating. X-ray crystal analysis of 1a and 2 confirmed the coplanar geometry between the thiophene and the NHC rings. In addition, as a consequence of a completely planar conformation of the bithiophene moiety, 2 forms a slipped face-to-face π-stacking array, in which the electron-rich thiophene rings are overlapped with the electron-deficient benzimidazolidene moieties of the adjacent molecules with the interfacial distance of 3.51 Å.

[1] K. Nagura, S. Saito, R. Fröhlich, F. Glorius, S. Yamaguchi, Angew. Chem. Int. Ed., in press.

Figure 1. Absorption spectral change of

1a in CH2Cl2 upon irradiation of a UV

light.

Figure 2. Packing structure of 2.

Poster 53

IRIS-13 Victoria

141

Oxidative Addition of Aryl- and Alkylditellurides to Pt(0) Centres

M. M. Karjalainen1, T. Wiegand,2 A. Wagner,2 H. Görls,2 R. Oilunkaniemi,1 R. S. Laitinen,1 W. Weigand2

(minna.karjalainen@oulu.fi) 1 Department of Chemistry, University of Oulu, P. O. Box 3000, FI-90014 University of Oulu, Finland,

2 Institut für Anorganische und Analytische Chemie, Humboldstrasse 8, 07743, Friedrich-Schiller-Universität, Jena, Germany

Oxidative addition of aryl- and alkyldiselenides to zerovalent platinum and palladium centres occurs usually with the cleavage of chalcogen-chalcogen bond. In the corresponding reactions of ditellurides, the Te-C bond cleavage is also possible.[1, 2] In this contribution the oxidative addition of ditellurides R2Te2 to [Pt(nb)(PP)] (nb = norbornylene) using various ditellurides (R = phenyl, 2-thienyl, n-butyl, t-butyl) and chelating diphosphines (PP = 1,2-bis(diphenylphosphino)ethane, 1,2-bis(diphenylphosphino)benzene, 1,2-bis(diphenylphosphino) naphthalene, 1,2-bis(diphenylphosphino)propane). The reactions produce two types of tellurolato complexes [Pt(TeR)2(PP)](1) and [Pt(TeR)(R)(PP)](2). The product distribution was monitored by 31P{1H} NMR spectroscopy and was found to depend strongly on the electron withdrawing or donating nature of the organic substituent of the ditelluride, as well as on the bite angle of diphosphine and the rigidity of diphosphine structure. In the reaction of (TePh)2 with [Pt(nb)(dppn)] the formation of 1 and 2 depend on the molar ratio of the reactants with excess of ditelluride, 1 is formed and with that of [Pt(nb)(dppn)], 2 is the main product. [1] R. Oilunkaniemi, R. S. Laitinen, M. Ahlgrén, J. Organomet. Chem. 2001, 623, 168. [2] A. Wagner, L. Vigo, R. Oilunkaniemi, R. S. Laitinen, W. Weigand, Dalton Trans. 2008, 3535.

1 2

Poster 54

IRIS-13 Victoria

142

Single Source Precursors as a Route to Doped Graphites

Timothy C. King and Dominic S. Wright (tk405@cam.ac.uk)

Department of Chemistry, University of Cambridge, UK Boron-doped graphite provides a range of technological differences compared to undoped graphite, including reduced oxidation and erosion rates (specifically with respect to plasma facing materials used in fusion reactors) and improved electrode performance in Li ion batteries. However, numerous previous invesigations have succeeded only with limited boron doping and normally samples are only several monolayers thick. Interest has recently been piqued in this area due to several computational studies on the hydrogen storage ability of boron-doped graphite, specifically BC3. These studies have stressed the importance of developing a reliable synthetic method of obtaining bulk samples of boron-rich material since chemisorption of H2 relies on cooperativity between the layers within the bulk and, for example, boron-doped monolayers and graphite itself are inactive in H-H bond cleavage. We describe here a single-source method of obtaining bulk amounts of ‘BC3’. This involves a facile carbonisation/graphitisation step that produces a material capable of storing 5 wt% hydrogen (only slight below the US-DoE minimum target).

Figure 5. The synthesis of boron doped graphites from a single-source precursor.

[1] J. Kouvetakis, R. Kaner, M. Sattler, and N. Bartlett, J. Chem. Soc., Chem., 1986, 1758-1759. [2] C. Lowell, J. Am. Ceram. Soc., 1967, 50, 142-144. [3] C. Zhang and A. Alavi, J. Chem. Phys., 2007, 127, 214704. [4] X. Sha, A. Cooper, and W. B. III, J. Phys. Chem., 2010, 3260-3264.

Poster 55

IRIS-13 Victoria

143

Planarized Triphenylboranes: Unique Structural Change in the Excited State

Tomokatsu Kushida,a Ayumi Shuto,a Tetsuro Katayama,b,d Syoji Ito,b Hiroshi Miyasaka,b Eri Sakuda,c Noboru Kitamura,c Cristoher Camacho Leandro,a Stephan Irle,a,e and Shigehiro Yamaguchia,e

(yamaguchi@chem.nagoya-u.ac.jp) a Department of Chemistry, Nagoya University, kushida@chem.nagoya-u.ac.jp b Department of Chemistry and Center for Quantum Material Science under Extreme Conditions, Osaka University, c Department of Chemistry, Hokkaido University, d JST-PRESTO, e JST-CREST, Furo, Chikusa, Nagoya, 464-8602, Japan

We have recently reported the synthesis of triphenylboranes planarized with three methylene tethers.[1] In the study of photophysical properties, we found that the compound exhibited dual emissions at room temperature, as shown in Figure 1. This phenomenon is unique for the planarized skeleton and not observed for normal unconstrained triarylboranes, such as trimesitylborane. To elucidate the origin of the luminescence properties, we have now measured the emission lifetimes as well as the transient absorption spectra, and rationalized those results based on the theoretical calculations in the excited state. The emission lifetimes were determined for each emission band. In the transient absorption spectra, two transient species corresponding to each lifetime of the two emission bands were successfully observed. Based on these experimental results as well as the structural optimization in the excited state, we concluded that this compound can have two local minimum structures, planar and bowl-shaped structures, in the lowest singlet excited state, each of which emits a fluorescence at the different wavelength (Figure 2). Phosphorescence properties at a low temperature will also be described.

[1] Z. Zhou, A. Wakamiya, T. Kushida, S. Yamaguchi J. Am. Chem. Soc., 2012, 134, 4529.

Poster 56

IRIS-13 Victoria

144

Easy Access to Backbone P-functionalized N-heterocyclic Carbenes and Complexes Thereof – en route to Novel Functional Ionic Liquids

Paresh Kumar Majhi, Susanne Sauerbrey and Rainer Streubel

(pmajhi@uni-bonn.de) Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms Universität Bonn,

Gerhard-Domagk-Str.1, 53121 Bonn, Germany Since the discovery of “bottleable” NHC’s by Arduengo et al.,[1] carbene chemistry has received renewed attention in coordination and main group chemistry, homogenous catalysis, and beyond. In recent years, introduction of an additional donor atom into an NHC has been subject of increased attention. In this regard, we will present the synthesis of mono- and di-phosphanyl and phosphoryl (n = 1, 2) (and/or PV; E = O, S, Se) substituted imidazol-2-thiones[2] (1, 4) and imidazolium salts (2, 5), obtained via oxidative desul-furization[3] of 1 and 4, respectively. Furthermore, reactions of 2 allow for in situ com-plexation to yield 3 (Scheme); evidence for P-functional NHC’s 6 will be also provided.[4]

[1] Arduengo III, A. J.; Harlow, R.L.; Kline, M. J. Am. Chem. Soc.1991, 113, 361-363. [2] Sauerbrey, S.; Majhi, P.K.; Schnakenburg, G.; Arduengo III, A. J.; Streubel, R. Dalton Trans. 2012,

41, 5368-5376 and Heteroatom Chem. 2012, accepted. [3] Morel, G. Synlett. 2003, 14, 2167-2170. [4] Majhi, P.K.; Schnakenburg, G.; Arduengo III, A. J.; Streubel, R. to be published.

Poster 57

IRIS-13 Victoria

145

Theoretical Study on SET-mediated Selective Bond Activation in Oxaphosphirane Complexes

Arturo Espinosaa and Rainer Streubelb

(artuesp@um.es) a Depto. Química Orgánica, Universidad de Murcia, Spain

b Institut für Anorganische Chemie, Rheinischen Friedrich-Wilhelms-Universität Bonn, Germany

Despite their potential use as powerful building blocks in organic synthesis, there is still scarce knowledge about heterocycles possessing three differently polar ring bonds such as in oxaphosphirane[1] and azaphosphiridines,[2] featuring a three-coordinated phosphorus centre. The chemistry of oxaphosphirane[3] (as well as azaphosphiridine[4]) complexes 1 is now emer-ging in ligand-centered ring forming reactions, as ring enlargement[5] and opening[6] reactions, taking advantage of the pentacarbonyl-metal(0) moieties as "inorganic protecting groups". Full exploration of oxaphosphirane chemistry would require the development of highly selective methods for exocyclic P-M and P-R bond cleavage while retaining the ring structure.

In this work, we provide first-time insights into the intrinsic strength of exocyclic bonds of phosphorus in oxaphosphirane complexes 1, following the me-thodology used in the case of azaphosphiridine analogues.[7] The heterolytic cleavage in 1 leading to a carbocation R+ and a oxaphosphiranide complex 2-

constitutes the lowest energy process of exocyclic P-R bond dissociation, especially if the group R is bulky and able to efficiently stabilize the positive charge, i.e. triphenylmethyl (trityl). The energies required for a P-M bond cleavage are about 30 kcal mol-1 and decrease with increasing bulk of the R substituent and on going from Cr to Mo. The reactivity of complexes 1 towards SET reactions was analysed using the facile VBSD (Variation on Bond Strength Descriptors) methodology, thus enabling the design of synthetically useful strategies addressing decomplexation and P-functionalization: reductive SET reactions (sodium naphthalenide) enable selective P-M bond cleavage (= decomplexation) for the case of P-Me and P-tBu substitution, whereas reductive P-R bond cleavage is favored in the case of the P-trityl complexes and results in the formation of the (anionic) oxaphosphiranide complex 2- which may be regarded as a potential key intermediate for further P-functionalization. [1] For 3

3-oxaphosphiranes proposed as reactive intermediates: Bartlett, P. A.; Carruthers, N. I.;

Winter, B. M. and Long, K. P. J. Org. Chem. 47 (1982) 1284. [2] For 1,23-azaphosphiridines, see: a) Niecke, E.; Seyer, A. and Wildbredt, D.-A. Angew. Chem. 96

(1981) 687. b) Dufour, N.; Camminade, A.-M. and Majoral, J.-P. Tetrahedron Lett. 30 (1989) 4813. [3] a) Bauer, S.; Marinetti, A.; Ricard, L. and Mathey, F. Angew. Chem. Int. Ed. Engl. 29 (1990) 1166; b)

Streubel, R.; Kusenberg, A.; Jeske, J. and Jones, P.G. Angew. Chem. Int. Ed. Engl. 33 (1994) 2427. [4] a) Streubel, R.; Ostrowski, A.; Wilkens, H.; Ruthe, F.; Jeske, J. and Jones, P. G. Angew. Chem. Int.

Ed. Engl. 36 (1997), 378; Vlaar, M. J. M.; Valkier, P.; de Kanter, F. J. J.; Schakel, M.; Ehlers, A. W.; Spek, A. L.; Lutz, M. and Lammertsma, K. Chem. Eur. J. 7 (2001) 3552.

[5] a) Helten, H.; Marinas Pérez, J.; Daniels, J. and Streubel R. Organometallics 28 (2009) 1221; b) Pérez, J. M.; Helten, H.; Schnakenburg, G. and Streubel, R. Chem. Asian J. 6 (2011) 1539.

[6] a) Pérez, J. M.; Helten, H.; Donnadieu, B.; Reed, C. and Streubel, R. Angew. Chem. Int. Ed. 49 (2010) 2615; b) Pérez, J. M.; Albrecht, C.; Helten, H.; Schnakenburg, G. and Streubel, R. Chem. Commun. 46 (2010) 7244.

[7] a) Espinosa, A.; Gómez, C. and Streubel, R. Inorg. Chem. (2012) DOI: 10.1021/ic300522g.

Poster 58

IRIS-13 Victoria

146

Synthesis and Characterization of Novel Cyclic Organotin Compounds

J. Binder, B. Seibt, R. Fischer and F. Uhlig (binder@tugraz.at)

Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria A large number of reports concerning derivatives with silicon and carbon groups (-R2Si-CH2-)n in the ring skeleton has been published in literature. However, only few studies are focused on the synthesis and reaction behavior of similar compounds containing also the higher elements of group 14. For that purpose different “flexible" spacers of type α-ω-bis(chlorodimethylsilyl)alkane (alkane chain length n = 2, 3, 4)[1] are used with diphenyltindichloride in the presence of magnesium in a Wurtz-type reaction yielding derivatives with various ring sizes. Also "rigid" spacers of type α-ω-bis(chlorodimethylsilyl)xylene/benzene are used in a similar reaction resulting in a series of silicon-bridged tin-indane derivatives. Furthermore the formation of analogous tin-indane derivatives with carbon as bridging atoms is reported. The preparation of these carbon bridged tin-indane derivatives using Wurtz-type coupling reactions[2, 3] does not lead to the selective formation of tin-indane derivates. Tetraline derivatives are formed as major byproduct. Therefore, we report here also on a novel reaction pathway towards the selective formation of tin-indane derivates (Scheme 1).

Scheme 1: Formation of carbon bridged tin-indane derivatives [1] Binder, J., Diplomarbeit, TU Graz, 2008 [2] Zarl, E., Ph. D. Dissertation, TU Graz, 2008 [3] Zarl, E., Uhlig, F., Zeitschrift für Naturforschung / B 64b, 2009, 1591 - 1596

Poster 59

IRIS-13 Victoria

147

Phosphorus-Based Flame Retardants for Paper

Andrew M. Priegert,1 Paul W. Siu,1 Thomas Q. Hu2 and Derek P. Gates1

(aprieger@chem.ubc.ca, dgates@chem.ubc.ca, thomas.hu@fpinnovations.ca)

1 Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T 1Z1, Canada

2 FPInnovations – Pulp and Paper Division, 3800 Wesbrook Mall, Vancouver, British Columbia, V6S 2L9, Canada

Traditional halogenated flame retardants such as polybrominated diphenyl ethers (PBDEs) are either being phased out or have already been banned in many jurisdictions worldwide. To replace them, there is a growing need for non-halogenated and non-leachable alternatives. As part of the growing interest in phosphorus-based flame retardants, novel phosphorus-containing polymers have been synthesized from the phosphaalkene MesP=CPh2 (Mes = 2,4,6-trimethylphenyl, Ph = C6H5). Discussed herein are the results of tests to evaluate their flame retardant properties when used to treat paper. The TAPPI (Technical Association of Pulp and Paper Industry) Standard Method T461 cm-00 was followed using paper made from thermomechanical pulp coated with polymer. Also to be presented are the results of thermogravimetric analyses (TGA) carried out on treated paper samples to evaluate thermal stability.

[1] Yam, M.; Chong, J. H.; Tsang, C.-W.; Patrick, B. O.; Lam, A. E.; Gates, D. P. Inorg. Chem. 2006,

45, 5225-5234 [2] Noonan, K. J. T.; Gates, D. P. Angew. Chem. Int. Ed. 2006, 45, 7271-7274 [3] Bates, J. I.; Dugal-Tessier, J.; Gates, D. P. Dalton Trans, 2010, 39, 3151-3159

Poster 60

IRIS-13 Victoria

148

Zeolite Inclusion Compounds of 1,2,3,5-Dithiadiazolyl Radicals

Hugh J. Cowley, Douglas R. Pratt and Jeremy M. Rawson (cowleyh@uwindsor.ca, jmrawson@uwindsor.ca)

Department of Chemistry and Biochemistry, University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada

A range of 1,2,3,5-dithiazolyl radicals such as 1 were synthesised and included within a faujasite (zeolite Y) lattice. Thermal gravimetric analysis and differential scanning calorimetry were used to determine radical loading within the lattice as well as the enthalpy of inclusion. The materials were characterised by powder X-ray diffraction and their magnetic character was determined by EPR spectroscopy. The effect of inclusion upon radical dimerisation and stabilisation will be discussed.

Poster 61

IRIS-13 Victoria

149

Synthesis and Characterization of 1,3,2-Diathiazolyl Radicals

Justin D. Wrixon, John J. Hayward and Jeremy M. Rawson (wrixon@uwindsor.ca, jmrawson@uwindsor.ca)

Department of Chemistry & Biochemistry, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada

A cost-efficient synthetic route to dialkoxy-benzene-substituted 1,3,2-dithiazolyl radicals has recently been developed by the Rawson group.[1] This methodology has been extended to a series of dialkoxy-substituted 1,3,2-benzodithiazolyl radicals, including dioxyl-benzo-1,3,2-dithiazolyl (DOXBDTA) and dioxepinyl-benzo-1,3,2-dithiazolyl (DOXEBDTA). The characterisation of these systems and the application of this methodology to more complex systems will be discussed.

[1] Alberola, A., Eisler, D., Less, R.J., Navarro-Moratalla, E., Rawson, J.M., Chem. Comm. 2010, 46,

6114-6116.

Poster 62

IRIS-13 Victoria

150

Structure and Reactivity of Low Oxidation State Indium Compounds with “Non-Innocent” Ligands

Christopher J. Allan, Benjamin F. T. Cooper, Hugh J. Cowley, Jeremy M. Rawson, Charles L. B.

Macdonald (allanc@uwindsor.ca, cmacd@uwindsor.ca)

University of Windsor, Canada In addition to exhibiting interesting fundamental chemistry, low oxidation state indium(I) compounds have proven to be effective catalysts in a variety of organic transformations (e.g. allylations at carbonyls, imines, benzylic ethers).[1] However, the coordination of neutral ligands, which may tune the selectivity or activity of such catalysts, to low-oxidation state indium halides generally results in disproportionation, producing indium metal and higher oxidative species.[2-4] In contrast, we report that the reaction of InOTf (OTf = trifluoromethanesulfonate)5 with “non-innocent” α-diimine (DAB) ligands afforded coloured products with no signs of indium metal being generated. We find that substituents present on the ligand can play a large role in the electronics of the system and in some instances yields radical and/or polymeric materials. In this work we present computational investigations, EPR spectra, cyclic voltammetry and X-ray crystal structures in order to elucidate the structure and chemistry of these InDAB complexes.

N N

InArAr N

N

In

Mes

Mes

N

N

In

Mes

Mes n

OTf

OTf

TfO

N NArAr

R R

InOTf

+R=Me

Ar=Mes or DippR=H

Ar=Mes

[1] Schneider, W.; Kobayashi, S. Acc. Chem. Res. 2012 ASAP [2] Pardoe, J. A. J.; Downs, A. J. Chem Rev. 2007, 107, 2. [3] Green, S.; Jones, C.; Stasch, A. Angew, Chem. Int. Ed. 2007, 46, 8618 [4] Cole, M. L.; Jones, C.; Kloth, M. Inorg. Chem. 2005, 44, 4909. [5] Cooper, B. F. T.; Macdonald, C. L. B. New J. Chem. 2010, 34, 1551.

Poster 63

IRIS-13 Victoria

151

EED studies on Chromium borylene

H. Braunschweig†, Ch. Lehmann‡, K. Radacki† (K.Radacki@uni-wuerzburg.de)

† Universität Würzburg, Am Hubland, 97074 Würzburg ‡ Max-Planck-Institut für Kohlenforschung; Mülheim an der Ruhr, Germany

Transition metal complexes of boron with electron-precise (2c,2e) MB bonds have become an area of widespread interest in the past decade. Terminal and dinuclear borylene complexes LxMBR, LxMB(R)M’Lx in particular owe much of their importance to the fact that they are closely related to pivotal organometallics such as carbonyl or vinylidene complexes. The structure of [(CO)5Cr=B=NR2] (1) was characterized by conventional single crystal diffraction already in 2001,[1] and analyzed in detailed by means of theoretical chemistry in 2007.[2] The investigation of the electronic structure on the basis of experimental electron densities (EED) in [{Cp(CO)2Mn}2(-BtBu)] (2), comprising bridging borylene ligand, showed unexpected features in Laplacian distribution of the central Mn2B-ring.[3] Recently, we were able to perform a high resolution X-Ray experiment on 1 and subsequent refinement in multipole formalism of Hansen and Coppens.[4] That gave us opportunity to analyze both theoretical and experimental data of 1, as well as to compare experimental densities of terminal borylene 1 with these of bridging borylen 2.

Experimental molecular graph (left) and Distribution of 2 (right) of 1.

[1] H. Braunschweig, M. Colling, C. Kollann, H.G. Stammler, B. Neumann Angew. Chem. Int. Ed. 2001,

40, 22982300. [2] B. Blank, H. Braunschweig, M. Colling-Hendelkens, C. Kollann, K. Radacki, D. Rais, K. Uttinger,

G. Whittell Chem. Eur. J. 2007, 13, 47704781. [3] U. Flierler et al. Angew. Chem. Int. Ed. 2008, 47, 43214325. [4] N.K. Hansen, P. Coppens Acta Cryst. 1978, A34, 909921. Acknowledgment: This work was supported by the Deutsche Forschungsgemeinschaft within SPP1178.

Poster 64

IRIS-13 Victoria

152

Phosphorus-Containing Copolymers for Suzuki Cross-Coupling

Tom H. H. Hsieh, Thomas W. Hey and Derek P. Gates (thsieh@chem.ubc.ca)

Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T 1Z1, Canada

Traditionally, monodentate and bidentate phosphines have comprised the majority of phosphorus-containing ligands in catalysis. The use of hybrid inorganic/organic phosphorus-containing polymers have been largely unexplored. We have previously reported that copolymers formed from the addition polymerization of phosphaalkene and styrene are capable of supporting transition metal cross-coupling catalysis.[1] We now report the recent developments in the ease of purification, increased substrate and catalyst scope, and ability to recycle the poly(methylenephosphine)-polystyrene copolymer (PMP-PS). Furthermore, copolymer microstructure and modifications, such as crosslinking with divinylbenzene, will be presented.

[1] Tsang, C.-W.; Baharloo, B.; Riendl, D.; Yam, M.; Gates, D.P. Angew. Chem. Int. Ed. 2004, 43, 5682.

Poster 65

IRIS-13 Victoria

153

Tin Catecholates

Zdenka Padelkova, Jan Turek, Hana Vankatova, Tomas Chlupaty and Ales Ruzicka (Zdenka.Padelkova@upce.cz)

Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, Pardubice 532 10, Czech Republic

The chemistry of organotin(IV) diols (making five- or six-membered -dioxastanna cycles) was extensively studied in the past in order to investigate the influence of mainly glycolic or catecholic arrangement to the geometrical as well as optical properties of the tin central atom. In these days, tin catecholates are thoroughly investigated in many fields of applications, mainly for their possible use in catalysis. They can be used for example in radical polymerization processes[1] because of their unique ability of accepting various radicals, including carbon ones. This was proved by polymerization of styrene and methylmetacrylate in presence of bis(catecholate)tin(IV) complex. In addition these complexes play an important role in regulation of chain length and they also provide linear growth of molecular weight of product with growing conversion rates of reaction. The preparation, structure and reactivity of different tin and germanium catecholates have been studied by Barrau, Jurkschat and others.[2] Our current interest is focused on the reaction products of different C,N- and N,N-chelated tin(II and IV) complexes (Fig. 1) with quinones or catecholates.

Fig. 1 Fragments of compounds studied The authors would like to thank the Grant Agency of the Czech Republic (grant no. P207/10/P092) for the financial support. [1] For example: L. B. Vaganova, E. V. Kolyakina, A. V. Lado, A. V. Piskunov, D. F. Grishin, Polymer

Science, Ser. B, 2009, 51, 96. [2] For example: K. Jurkschat, N. Pieper, S. Seemeyer, M. Schuermann M. Biesemans, I. Verbruggen, R.

Willem Organometallics 2001, 20, 868; J. Barrau, G. Rima, T. El-Amraoui, J. Organomet. Chem. 1998, 561, 167.

Poster 66

IRIS-13 Victoria

154

Cpbig Complexes of Low Valent Main Group Metals

Dominik Naglav and Andreas Schnepf (dominik.naglav@stud.uni-due.de, andreas.schnepf@uni-due.de)

Fakultät für Chemie, Universität Duisburg-Essen, 45141 Essen, Germany The reaction of KCpbig [Cpbig = C5(CH2C6H4-iPr)5, C5(C6H5)5] with low valent main group metal sources like “Ga(+1)I” and Ge(+1)Cl under mild conditions yielded in the formation of novel cpbig complexes. Depending on the low valent metal precursor the increased sterical demand of the ligand can not only avoid the formation of oligomeric species (in case of “GaI”) but can also enforce the formation of large cluster compounds (in case of GeCl).[1-3]

We were able to synthesize a dynamic sandwich complex of germanium in the oxidation state +2 as a product of the controlled disproportionation reaction of Ge(+1)Cl with KCpbig to Ge(Cpbig)2

and metalloid cluster compounds (GenLm with n > m) and KCl. The solid state structure of (1) shows that in the case of the CpiPrBz5 ligand the formation of a bent conformation is preferred in solid state due to the lone-pair-π interaction of the carbenoid Ge2+ metal center with two of the aromatic benzyl substituents of the cp. Theoretical investigations confirm that the parallel conformation is preferred by 3.4 kJ/mol in comparison to the bent conformation, which indicates that the parallel structure is mainly present in solution. Cryogenic 1H-NMR studies verify this assumption as all benzyl substituents are equivalent in solution even at −80 °C .[1]

Molecular structure of GeCpbig2 [Cpbig = C5(CH2C6H4-iPr)5] and equilibrium of the open and closed form of 1 in solution (theoretical calculations)

[1] Dominik Naglav, Briac Tobey, Sjoerd Harder and Andreas Schnepf, submitted to ZAAC. [2] Andreas Schnepf, New. J. Chem., 2079-2092, 34, 2010. [3] Hansgeorg Schnöckel, Andreas Schnepf, Angew. Chem., 3682-3703, 114, 2002.

Poster 67

IRIS-13 Victoria

155

(Me3Si)2NPCl2 – A Molecule with a “Disguised” PN-Moiety

Christian Hering,a Axel Schulz a,b and Alexander Villingera

(christian.hering@uni-rostock.de)

a Universität Rostock, Institut für Chemie, Abteilung Anorganische Chemie, Albert-Einstein-Straße 3a, 18059 Rostock, Germany; b Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-

Str. 29a, 18059 Rostock, Germany Molecules such as R(Me3Si)N-PCl2 (R = Ter, Mes*, SiMe3) that can release in situ a highly reactive dipolarophile [R-NP]+ by Me3SiCl elimination in the presence of a Lewis acid (GaCl3), are often referred to as “disguised” dipolarophiles. These silylated dichlorophosphanes are excellent starting materials for the formation of tetrazaphospholes of the type, RN4P∙GaCl3. Just recently we reported on the synthesis of an ionic liquid containing the [Me3Si-NP]+ cation, which is formed, when (Me3Si)2NPCl2 (1) was reacted with GaCl3.[1] Following our interest in compounds with a binary N–Pn (Pn = P, As, Sb, Bi) moiety we have studied if elimination of a second equivalent Me3SiCl starting from 1 is possible. Therefore the application of 1 as a precursor for diatomic PN, the heavier homologue of N2, is envisioned. Analogous P2 is well known and starting from a solution of P4 in hexane the transient species could be trapped with suitable organic acceptors.[2] In a first series of experiments the thermal release of Me3SiCl in 1 in the presence of the trapping reagent 2,3-dimethyl-butadiene (dmb) was investigated resulting, according to 31P NMR studies, in the clean conversion to a cyclotetraphosphazane [PN(dmb)]4 (2),[3] incorporating four PN-fragments. Substituting the chlorine atoms in 1 by triflate groups yields (Me3Si)2NP(OTf)2 which should also generate “PN” upon thermal elimination of TfOSiMe3. If this elimination is carried out in the presence of dmb, the formation of the spirocyclic compound [(Me3Si)NP(dmb)2][O3SCF3] (3) is observed. We present here first results on the application of 1 as a synthetic equivalent for PN in inorganic as well as in organic chemistry and report on the synthesis of new cyclic phosphazenes and their application as ligand in transition metal chemistry (Figure 1).

Figure 1. Cyclotetraphosphazene 2 (left) and 2∙W2(CO)7 (right). [1] (a) A. Villinger, P. Mayer and A. Schulz, Chem. Commun., 2006, 1236; (b) C. Hering, A. Schulz, A.

Villinger, Angew. Chem. Int. Ed. 2012, 51, 6241-6245. [2] (a) N. A.Piro, J. S. Figueroa, J. T.McKellar, C. C. Cummins, Science 2006, 313, 1276. (b) D. Tofan,

C. C. Cummins, Ang. Chem. Intl. Ed. 2010, 49, 7516. [3] K. D. Gallicano, N. L. Paddock, Can. J. Chem.1985, 63, 314.

Poster 68

IRIS-13 Victoria

156

Coordination Chemistry of the Pentacyanocyclopentadienide Anion

Thomas C. Wilson, Robert J. Less and Dominic S. Wright (tcw35@cam.ac.uk)

University of Cambridge, UK The pentacyanocyclopentadienide anion, 1 (Fig. 1), has been little studied and has been claimed to be ‘almost totally non-coordinating’.[1] However, recent studies[2] have shown this not to be the case, and altering the synthesis to give a thermodynamic driving force for the reaction has proved successful (Eqn. 1).

The readily accessible sodium salt Na[1] can then be reacted with metal halide salts (Eqn. 2) to yield novel complexes. Due to the presence of five electron-withdrawing groups, 1 acts as a -donor through the cyano groups, rather than as a ligandvia the C5 ring. Both CoCl2 and CuCl2 were reacted with Na[1], and the resulting complexes are reported here. In addition to this, a family of Group 11 phosphine complexes involving 1 are also reported.[3] The latter are the first complete series of cyclopentadienyl compounds to be structurally characterised for any group in the Periodic Table. The ion paired gold complex, Au(PPh3)2[1], is shown below (Fig. 2).

Figure 1 (left): The pentacyanocyclopentadienide anion, 1 Figure 2 (right): Au(PPh3)2[1] [1] A. F. Williams etal., Chem. Eur. J., 2009, 15, 5012 [2] D. S. Wright etal., Chem. Eur. J., 2010, 16, 13723 [3] D. S. Wright et al., Chem. Commun., 2011, 47, 10007

Poster 69

IRIS-13 Victoria

157

Supramolecular Chemistry of N-Alkyl-Benzo-2,1,3-Selenadiazolium Cations

Lucia Myongwon Lee, Victoria B. Corless, Michael Tran, Dora P. Hsieh, Faisal Adampani, Christine Li and Ignacio Vargas-Baca (leem35@univmail.cis.mcmaster.ca, vargas@chemistry.mcmaster.ca) Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West,

Hamilton, Ontario, L8S4M1, Canada In supramolecular chemistry, there is increasing interest in the use of main-group secondary bonding interactions (SBIs) as a tool to control the structures and properties of materials. The efficient application of SBIs would require the use of the best supramolecular synthons, the structural motifs created by operations of supramolecular synthesis. The ideal supramolecular synthon would be strong and directional such features are characteristic of systems assembled by more than one contact point, for example, the [E-N]2 supramolecular synthon which is frequently formed by molecules containing the 1,2,5-chalcogenadiazole ring in their structure.[1] Derivatives of 1,2,5-telluradiazole were shown to exhibit functional properties such as chromotropism and second-order non-linear optical activity. However, they are easily degraded by hydrolysis, which limits their application.[2] The selenium analogues behave in a similar fashion but with weaker intermolecular forces. The N-alkylated heterocycles display shorter SBI distances than their neutral analogues.[3,4,5] This observation suggests that the positive charge of the molecule enhances the electron acceptor ability of the chalcogen, strengthening the supramolecular interaction. Direct alkylation of benzo-2,1,3-selenadiazole had been regarded as difficult, being successful only with vigorous alkylating agents.[3,4,5,6] It was shown recently that in some cases the reaction with alkyl iodides does proceed in mild conditions, as long as it is carried out under an inert atmosphere. A more convenient method of preparation of the N-alkylated cations starts with the N-alkyl-o-phenylenediamine and selenium dioxide in acidic medium.[7,8] This method enables the preparation of a wide range of derivatives that can be used as supramolecular building blocks, most notable are novel bridged dicationic species, capable of assembling extended structures.

[1] (a) Cozzolino, A. F.; Vargas Baca, I.; Mansour, S.; Mahmoudkhani, A. H. J. Am. Chem. Soc. 2005,

127, 3184; (b) Cozzolino, A. F.; Elder, P. J. W.; Vargas Baca, I. Coord. Chem. Rev. 2011, 255, 1426.

[2] (a) Cozzolino, A.F.; Whitfield, P. S.; Vargas-Baca, I. J. Am. Chem. Soc. 2010, 10, 4459; (b) Cozzolino, A. F.; Yang, Q.; Vargas-Baca, I. Cryst. Growth Des. 2010, 10, 4459.

[3] Risto, M.; Reed, R. W.; Robertson, C. M.; Oilunkaniemi, R.; Laitinen, R. S.; Oakley, R. T. Chem. Commun. 2008, 3278.

[4] Dutton, J. L.; Tindale, J. J.; Jenings, M. C.; Ragogna, P. J. Chem. Commun. 2006, 2474. [5] Berionni, G.; Pégot, B.; Marrot, J. CrystEngComm. 2009, 11, 986. [6] (a) Nunn, A. J.; Ralph, J. T. J. Chem. Soc. 1965, 6769; (b) Nunn, A. J.; Ralph, J. T. ibid. C 1966,

1568. [7] (a) Eremeeva, G. I.; Strelets, B. K.; Efros, L. S. Khim. Geterotsikl. Soedin. 1975, 276; (b) Eremeeva,

G. I.; Strelets, B. K.; Efros, L. S. Ibid. 1976, 340; (c) Eremeeva, G. I.; Akulin, Y. I.; Timofeeva, T. N.; Strelets, B. K.; Efros, L. S. ibid. 1982, 1129; (d) V.B. Corless, Senior Undergraduate Thesis, McMaster University 2012.

[8] Neve, J.; Hanocq, M. Talanta 1979, 26, 15.

Poster 70

IRIS-13 Victoria

158

Small Molecule Activation by Anti-Aromatic Boroles

Adrian Y. Houghtona, Cheng Fana, Heikki M. Tuononenb and Warren E. Piersa

(ayhought@ucalgary.ca)

a Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4, Canada

b Department of Chemistry, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland

The past few years have witnessed an increasing interest in the five-membered unsaturated boracycles known as boroles.[1] These compounds are anti-aromatic, have high Lewis acidity, and possess interesting electronic properties. Recently, the Piers group has demonstrated the unexpected activation of dihydrogen by pentaarylboroles (figure 1).[2,3] This unique reactivity has prompted the investigation of the its mechanism, as well as the extension of the known borole library to include 1-boraindenes (figure 2). This presentation focuses on the kinetics of dihydrogen activation and the synthesis 1-boraindenes starting from diarylzirconocenes and diarylacetylenes.

[1] Braunschweig, H.; Kupfer, T., Chem. Commun. 2011, 47, 10903–10914 [2] A. Fan, C.; Mercier, L. G.; Piers, W. E.; Tuononen, H. M.; Parvez, M., J. Am. Chem. Soc, 2010, 132

(28), 9604-9606. [3] Fan, C.; Piers, W. E.; Parvez, M., Angew. Chem. Int. Ed, 2009, 48 (16), 2955-2958.

Poster 71

IRIS-13 Victoria

159

Probing the Group Tolerance of a Li/Cl Phosphinidenoid Complex Using -, - and -Substituted Aldehydes

Melina Klein and Rainer Streubel

(melinaklein@uni-bonn.de) Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms Universität Bonn, Gerhard-Domagk-

Str.1, 53121 Bonn, Germany First synthesis of a σ4λ5-oxaphosphirane[1] was reported by Röschenthaler (1978) and the first oxaphosphirane complexes were described by Mathey (1990)[2] but no further studies appeared. Although a new synthetic method was reported in the following years (1994-1997), namely the phosphinidene complex transfer reaction,[3] the breakthrough was achieved recently when Li/Cl phosphinidenoid complexes were reacted with aldehydes (2007).[4] Here, reactions of Li/Cl phosphinidenoid complex 2a, generated at low temperature,[4] with various aldehydes bearing a functional group in α-, β- or -position and/or ketones[5] to give oxa-phosphirane complexes 3-9 or an isomeric product (10) will be presented. In addition, first studies on reactions of complexes 2a,b with DMF will be reported.

Interestingly, exclusively 1,2-cycloaddition[6] occurred thus showing clear preference of the nucleophilic intermediate 2. NMR data, structures as well as the case of atropisomerism at the exo P-C bond in complexes 5-9 will be discussed.[6] Furthermore, preliminary results on reductive SET ring-opening reactions of some oxaphosphirane complexes using the systems Ti(Cp)2Cl2/Zn, TiCpCl3/Zn and TiCl3(thf)3 will be presented.

[1] Röschenthaler, G.V.; Sauerbrey, K.; Schmutzler, R. Chem. Ber. 1978, 111, 3105. [2] Bauer S.; Marinetti, A.; Ricard, L.; Mathey, F. Angew. Chem. 1990, 102, 1188. [3] Streubel, R.; Kusenberg, A.; Jeske, J.; Jones, P. G. Angew. Chem. 1994, 106, 2564. [4] Özbolat, A.; von Frantzius, G.; Nieger, M.; Streubel, R. Angew. Chem. 2007, 119, 9488. [5] Pérez, J.M.; Klein, M.; Kyri, A.; Schnakenburg, G.; Streubel, R. Organometallics 2011, 30, 5636. [6] Streubel, R., Klein, M.; Schnakenburg, G. Organometallics 2012, DOI: 10.1021/om300177c.

Poster 72

IRIS-13 Victoria

160

Structural Diversity and Reactivity of New Phosphine-Stabilized Antimony

Centers

Saurabh S. Chitnis and Neil Burford (sschitnis@gmail.com)

Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada Coordination chemistry has been applied successfully to achieve a variety of rare and reactive bonds

between the heavy pnictogen elements (P, As, Sb, and Bi).[1-3]

We have reported on the structural

diversity observed in bidentate phosphine complexes of antimony-centered cations,[4]

and have since

discovered additional P-Sb bonding frameworks, highlighting a rich structural chemistry of ligand-

stabilized antimony centers. Considering the metallic nature of antimony and its ability to achieve high

coordination numbers, we propose re-envisioning these complexes as main-group analogues of the

organo-transition metal complexes used in modern homogeneous catalysis. The prospect of replacing

expensive transition metals with cheaper and more abundant main-group metals in catalysis is an

attractive one. Most catalysts operate via a ligand association-modification-dissociation cycle. To assess

the potential catalytic activity, we have studied the interaction of unsaturated organic fragments such as

alkenes, dienes, ketones and nitriles with organo-antimony complexes described earlier. The structure of

new P-Sb complexes and their reactivity towards organic molecules will be presented.

[dppm(SbCl3)2] [dppmSbCl2]

+ [dppmSbCl]

2+ [dppmSb]

3+

[1] C. A. Dyker, N. Burford, Chem. Asian. J., 2008, 3, 28.

[2] E. Conrad, N. Burford, et. al., J. Am. Chem. Soc., 2009, 131, 5066.

[3] E. Conrad, N. Burford, et. al., Chem. Commun., 2010, 46, 2465.

[4] S. S. Chitnis, N. Burford, et. al., Chem. Commun., 2011, 47, 12331.

Poster 73

IRIS-13 Victoria

161

Synthesis and Structural Characterization of Indium-Oxygen-Organic Network Solids

Glen G. Brianda, Marshall R. Hoeya, and Andreas Deckenb

(gbriand@mta.ca) aDepartment of Chemistry and Biochemistry, Mount Allison University, Sackville NB, Canada

bDepartment of Chemistry, University of New Brunswick, Fredericton, NB, Canada

Indium oxide (In2O3) is a transparent conducting oxide with a number of applications in thin film form, such as liquid crystal displays, gas sensors, solar cells, light emitting diodes and other optoelectronic devices. It has been shown that molecule-based extended solids containing both inorganic and organic components represent materials with “tunable” physical properties, such as conductivity (Vaid et al. J. Am. Chem. Soc. 2008, 130, 14). Covalent bonding in these materials results in the high electron-hole mobilities of inorganic materials, while the molecular components allow for the fine-tuning of physical properties that is possible with organic materials. As an extension of or previous work with dimethylindium and -thallium chalcogenolates (Dalton Trans., 2010, 39, 3833; Eur. J Inorg Chem., 2011, 2298; Eur. J. Inorg. Chem., 2011, 5430), we have studied the reaction of trimethylindium with various benezendiols and-triols to yield extended –(Me2IIn(OR)2InMe2)- networks. The syntheses and structural characterization of isolated materials will be discussed, as well as their potential as tunable conducting materials.

Poster 74

IRIS-13 Victoria

162

Exploring the Coordination Chemistry of Lead(II) Thiolates

Glen.G. Brianda, Teri J. Gullona, Andrew D. Smitha, Anita S. Smitha and Gabriele Schatteb

(gbriand@mta.ca) aDepartment of Chemistry and Biochemistry, Mount Allison University, Sackville NB, Canada

bSaskatchewan Structural Sciences Centre, University of Saskatchewan, Saskatoon SK, Canada Despite the potential of heavy p-block metal (i.e. Tl, Pb, Bi) thiolates as interesting Lewis acids, little structural data for their coordination complexes have been reported. Previously, we have synthesized and structurally characterized a number of adducts of (2,6-Me2C6H3S)2Pb with monodentate, bridging, and chelating amine and phosphine ligands (Inorg. Chem., 2007, 46, 8625; Dalton Trans. 2004, 3515). This has resulted in the isolation of a variety of interesting bonding environments for lead(II). In an effort to increase the Lewis acidity at the lead(II) center, we have also prepared the cationic lead(II) thiolate {[4-(Me3N)C6H4S)6Pb3]6+ using a zwitterionic ammonium thiolate ligand. This trinuclear species reacts with amine ligands to give mononuclear {[4-(Me3N)C6H4S]2Pb}2+

Ln complexes (Polyhedron., 2012, 33, 171). To further explore this system, we have prepared (2-MeC6H4S)2Pb which incorporates less bulk at the lead(II) centre versus (2,6-Me2C6H3S)2Pb. We will discuss the preparation and solid-state structure of this complex, as well the coordination complexes resulting from its reaction with mono- and diamine ligands.

Pb:

L

LRS

RSPb:

L

S'RS

RSPb:

N

SRRS

NPb:

SR

SRP

P

Pb:

P

RS

RSPb:

L

RS

RSPb:

SR

S'RS

L

Poster 75

IRIS-13 Victoria

163

Poly(methylenephosphine)s Containing Fluorescent Substituents as Chemosensors

Benjamin W. Rawe, Cindy P. Chun, Derek P. Gates

(brawe@chem.ubc.ca, dgates@chem.ubc.ca) Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1,

Canada Polymeric chemosensors are practical materials used to detect potentially dangerous spieces pat very low concentration levels.[1] This presentation will illustrate how poly(methylenephosphine)s (PMPs),[2,3] bearing conjugated substituents can be used as "turn on" chemosensors (scheme 1). The polymers are prepared by anionic initiation of the phosphaalkene monomers (PA) featuring conjugated polyaromatic substituents. The unfunctionalized polymers (PMP-U) display low luminescence as the emission is quenched by the phosphorus lone pairs in the main chain of the polymer. Upon coordinating the phosphorus centres to a Lewis acid analyte (A) the emission from the polymers (PMP-A) substantially increase. The potential sensor applications for PMP's as well as the range of analytes that can be detected using florescence techniques will be outlined.

[1] Kim, H. N.; Guo, Z.; Zhu, W.; Yoon, J.; Tian, H. Chem Soc Rev.,2011, 40, 79-93 [2] Tsang, C. W.; Yam, M.; Gates, D. P. J. Am. Chem. Soc., 2003, 125, 1480-1481 [3] Bates, J. I.; Dugal-Tessier, J.; Gates, D. P. Dalton Trans., 2010, 39, 3151-3159

Scheme 1: The polymerisation of phosphaalkenes and functionalization of poly(methylenephosphine)s to yield novel chemosensor materials.

Poster 76

IRIS-13 Victoria

164

Thermal Ring Closure of Aminopropylstannanes

J. Pichler and F. Uhlig (johann.pichler@tugraz.at)

Institute of Inorganic Chemistry, Graz University of Technology Stremayrgasse 9/V, A-8010 Graz, Austria

One of the main research interests of our group is focused on the development of novel, functionalized ring systems containing heavy group 14 elements. Such derivatives provide new synthetic applications in polymer chemistry, in catalysis as well as concerning biological activity. Investigations on the properties of currently synthesized organtin compounds containing amino propyl substituted side chains1 lead to cyclostannazanes. They tend to be easily accessible via mild thermal ring closure reactions under reduced pressure (Figure 1).

Figure 1 The occurring protodearylation enables us to synthesize the target compounds in high yield and purity. All of these cyclostannazanes are characterized by state-of-the-art techniques.

Poster 77

IRIS-13 Victoria

165

Synthesis of Low Coordinate Group 13 and 14 Complexes Stabilized by Chelating Anionic Phosphine Ligands

Jonathan W. Dube, Brian Malbrecht, Sarah Weicker and Paul J. Ragogna

(jdube7@uwo.ca, pragogna@uwo.ca) Department of Chemistry and the Center for Materials and Biomaterials Research, Western University,

1151 Richmond St, London, Ontario, N6A 5B7, Canada A majority of the isolated low valent group 13 and 14 compounds are prepared from hard anionic nitrogen based ligands,[1,2] while much less explored is the chemistry of the main group elements with the anionic phosphinoborate ligand class developed by Peters et al.[3-5] In this context, unique gallium, germanium, and tin complexes have been isolated from the reaction of 1 with the corresponding lower oxidation state main group halide. For Ge and Sn, 2 is formed in quantitative yields and the onwards reactivity was pursued. In the case of gallium, a novel base stabilized Ga2I2

2+ dimer (3) is prepared in yields that vary depending on the “GaI” preparation time. This finding prompted a study on the nature of “GaI” as a function of reaction time with solid-state characterization methods and model reaction outcomes being presented.

[1] M. Assay, C. Jones, M. Driess, Chem. Rev. 2010, 111, 354. [2] R.J. Baker, C. Jones, Dalton Trans. 2005, 1341. [3] J.C. Thomas, J.C. Peters, J. Am. Chem. Soc. 2001, 123, 5100. [4] J.C. Thomas, J.C. Peters, Inorg. Chem. 2003, 42, 5055. [5] A.A. Barney, A.F. Heyduk, D.G. Nocera, Chem. Commun. 1999, 2379.

Poster 78

IRIS-13 Victoria

166

P-substituent Effects on the Insertion of Group 14 Carbenoids into Phosphorus–Halogen Bonds

Joseph K. West and Lothar Stahl

(westjoek@gmail.com, lstahl@chem.und.edu) Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202-9024 USA

The cyclic heterocarbenoids Me2Si(-NtBu)2M (M = Ge and Sn) insert with varying rates into the phosphorus-chlorine bonds of aminochlorophosphines, arylchlorophosphines, and the thiophosphine PhP(S)Cl2. The reaction rates depend on both the steric bulk of the phosphines and the nature of the heterocarbenoid, the stannylene usually being significantly more reactive. The tin(IV) insertion products so created, however, also decompose much more rapidly than their germanium(IV) analogs. As is shown in the Scheme below, the decomposition of the insertion product can be significantly reduced, or even prevented, if the organic substituents on phosphorus bear greater steric bulk. Based on such qualitative observations, accompanied by detailed structural and kinetic data, plausible pathways for the insertion and decomposition mechanisms will be proposed.

NSi

NSn

tBu

tBu

P

Cl

P

ClNSi

NSn

tBu

tBu

PPh2NSi

NSnCl2

tBu

tBu

+(PhP)n

n = 3Š5 NSi

NSn

tBu

tBu

P

Cl

STABLE

Cl

[1] Veith, M.; Grosser, M.; Huch, V. Z. Anorg. Allg. Chem. 1984, 513, 89–102. [2] Veith, M.; Gouygou, M.; Detemple, A. Phosphorus, Sulfur Silicon Relat Elem. 1993, 75, 183–186. [3] West, J. K.; Stahl, L. Organometallics 2012, 31, 2042–2052.

Poster 79

IRIS-13 Victoria

167

Metalloxanes Supported by Nitrogen Rich Heterocycles Comprising

Chalcogen Donor Atoms

Raymundo Cea-Olivares1, Christian Gil

2, Mónica Moya-Cabrera

2, §, Vojtech Jancik

2, §

(cea@unam.mx, monica.moya@unam.mx) 1Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad

Universitaria, C.P. 04510, México 2Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carr. Toluca-Atlacomulco

Km 14.5, C.P. 50200, Toluca, Estado de México, México. §Academic staff from the Universidad Nacional

Autónoma de México

Recently, we reported on the preparation of metal chalcogenide compounds bearing 4,5-

bis(diphenylphosphoranyl)-1,2,3-triazole ligands [H{4,5-(P(E)Ph2)2tz} (E = S(1), Se(2); tz =1,2,3-

triazole].[1–3]

The use of these types of ligands can lead to discrete structural arrangements for metals with

a high tendency for oligomerization.

Herein, we report on the preparation of lanthanide, aluminium and magnesium metalloxanes [(LnCp{4,5-

(P(Se)Ph2)2tz})2(LnCp)(-O)] (Ln = Y (3), Sm(4)), [(Al(OH){4,5-(P(E)Ph2)2tz})3(-O)] (E = S (5), Se

(6)) and [Mg{4,5-(P(S)Ph2)2tz}]2(-OH) (7) obtained from controlled hydrolysis of their corresponding

chalcogenide derivatives. The structural analyses in solid state for 3 – 7 reveal that in all cases, the

presence of a metalloxane moiety (M-O-M), as well as metal-chalcogen bonding (Figure 1). The degree

of the aggregation observed for these compounds depends significantly on the size of the metal center as

well as on the metal:ligand ratio employed for each reaction.

Figure 1. Molecular structure of a metalloxane containing a Sm3O core.

[1] Balanta-Diaz, J. A.; Moya-Cabrera, M.; Jancik, V.; Pineda-Cedeno, L. W.; Toscano, R. A.; Cea-

Olivares, R., Inorg. Chem. 2009, 48, 2518–2525.

[2] Alcantara-Garcia, J. Jancik, V.; Barroso, J.; Hidalgo-Bonilla, S.; Cea-Olivares, R.; Toscano, R. A.;

Moya-Cabrera, M., Inorg. Chem. 2009, 48, 5874–5883.

[3] Balanta-Diaz, J. A.; Moya-Cabrera, M.; Jancik, V.; Toscano, R. A.; Morales-Juarez, T. J.; Cea-

Olivares, R., Z. Anorg. Allg. Chem. 2011, 637, 1346–1354.

Poster 80

IRIS-13 Victoria

168

Definitive Structural Evidence for Phosphaamidines in Tautomeric C=P and C=N forms and Further Elaboration to Phosphaguanidines,

Phosphinodiimines and Amidinophosphaalkenes

L. Mokhtabad Amrei,a R. T. Boeréa and J.D. Masudab

(boere@uleth.ca)

aDepartment of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, AB T1T3M4 , Canada bThe Maritime Centre for Green Chemistry and Department of Chemistry, St. Mary’s University, Halifax,

NS B3H3C3, Canada P(III)-phosphaamidines replace one of the nitrogen atoms in an amidine by phosphorus.[1-3] Such phosphaamidines have been reported to exist in two tautomeric forms 1 and 2, but previously only the aminophosphaalkene form 1 has been structurally confirmed.[1] Here we report crystallographic evidence for two examples with the other tautomeric form 2. In addition, there is convincing spectroscopic evidence that 1,2(R=aryl;R1=R2=2,6-diisopropylphenyl) exist in solution as equilibrium mixtures. We also report on the chemical elaboration of the phosphaamidine functional group in related forms including the phosphaguanidine 3, P(III)-phosphinodiimines 4 and P(III)-amidinophosphaalkenes 5.

RNH

P R1

R2

RPH

N R1

R2

NHPH

N R1

R2

R3

N

P

N

R R

R1 R

3

R2

N

N

P

R R

R1 R

3

R2

1 2 3 4 5

[1] R. T. Boere, M. L. Cole, P. C. Junk, J. D. Masuda, G. Wolmershauser, Chem. Comm. 2004, 2564-

2565. [2] X. F. Li, H. B. Song, C. M. Cui, Dalton Trans. 2009, 9728-9730. [3] M. Y. Song, B. Donnadieu, M. Soleilhavoup, G. Bertrand, Chem.-Asian J. 2007, 2, 904-908. [4] J. D. Masuda, D. W. Stephan, Dalton Trans. 2006, 2089-2097. [5] J. D. Masuda, D. W. Stephan, Can. J. Chem. 2005, 83, 477-484.

Poster 81

IRIS-13 Victoria

169

Scorpionate Ligands Based on Nickel or Cobalt Chalcogenophosphoranyltiazolates

Jesús Pastor-Medrano,a Erandi Bernabé-Pablo,b Marisol Reyes-Lezama,b T. Jesús Morales-Juarez,a

Vojtech Jancik,b,§ (jmoralesj@uaemex.mx, vjancik@unam.mx)

a) Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón Esq. Paseo Tollocan, C.P. 50120, Toluca, Estado de México, México. b) Centro Conjunto de Investigación en

Química Sustentable UAEM-UNAM, Carr. Toluca Atlacomulco km. 14.5, C.P. 50200, Toluca, Estado de México, México. §Academic staff from the Universidad Nacional Autónoma de México

The term scorpionate ligand was used for the first time for tris(pyrazolyl)borates, where the pyrazol units are usually substituted in the 4- or 3,5-positions to increase their solubility and steric bulk.[1] Many metallic complexes with these ligands have been prepared as models for enzyme active sites. Herein, we report on a scorpionate ligands formed in the reaction between Ni2+ or Co2+ and three equivalents of 4,5-(Ph2PE)2Tz (E = S, Se, Tz = 1,2,3-triazol).[2] The ligands are readily prepared in the form of a potassium salt and are air stable. The obtained compounds have been characterized by common analytical methods.

Figure 1. Molecular structure of a potassium salt of the scorpionate ligand based on nickel and selenaphosphoranyltriazolate with thermal ellipsoids at 50 % probability only for noncarbon atoms. Hydrogen atoms have been omitted for clarity. [1] S. Trofimenko, Scorpionates: Polypyrazolylborate Ligands and Their Coordination Chemistry. World

Scientific Publishing Company, 1999. [2] Jesús Pastor-Medrano, Erandi Bernabé-Pablo, Marisol Reyes-Lezama, T. Jesús Morales-Juarez,

Vojtech Jancik, manuscript in preparation.

Poster 82

IRIS-13 Victoria

170

On the Structural Diversity of Aminotrialkoxides of Tin and Related Tin-Oxo Clusters

T. Zöller, Ljuba Iovkova-Berends, Christina Dietz and K. Jurkschat

(thomas.zoeller@tu-dortmund.de)

Lehrstuhl für Anorganische Chemie II der Technischen Universität Dortmund, Otto-Hahn-Str. 6, 44227 Dortmund, Germany

Metal(IV)-derivatives of triethanolamines are called Metallatranes[1] and hold great potential as Lewis-acid catalysts.[1,2] Organostannatranes N(CH2CH2O)3SnR are known for a long time[1a] but purely inorganic representatives that lack any tin-carbon bond are scarce.[3] Our motivation for the synthesis of such compounds results from their non-toxicity and their potential as delayed action catalysts in the polyurethane formation.[2c] Here we report the syntheses and structures of tin aminotrialkoxides of the types A, B and C.[3] A systematic variation of the substituents X and R allows controlling the switch-temperature of the catalysts but gives also access to great structural diversity. These compounds hold, by partial hydrolysis, potential as precursors for unusual tin-oxo clusters of high nuclearity, such as D and E.

[1] a) J. G. Verkade, Coord. Chem. Rev., 1994, 137, 233. b) A. Singh, R. C. Mehrotra, Coord. Chem.

Rev., 2004, 248, 101. [2] a) W. A. Nugent, J. Am. Chem. Soc., 1992, 114, 2768. b) F. Di Furia, G. Licini, G. Modena, R.

Motterle, W. A. Nugent, J. Org. Chem., 1996, 61, 5175. c) J. Krause, S. Reiter, S. Lindner, A. Schmidt, K. Jurkschat, M. Schürmann, G. Bradtmöller, DE 102008021980, 2008. d) P. M. Gurubasavaraj, K. Nomura, Inorg. Chem. 2009, 48, 9491. e) S.-d. Mun et al., J. Organomet. Chem. 2007, 692, 3519.

[3] T. Zöller, C. Dietz, L. Iovkova-Berends, O. Karsten, G. Bradtmöller, A.-K. Wiegand, Y. Wang, V. Jouikov, K. Jurkschat, Inorg. Chem. 2012, 51, 1041.

Sn1 Sn2

Sn3 Sn4

N

O

N

O

Sn1

Sn2 Sn3

D

methyl groups are omitted E

Poster 83

IRIS-13 Victoria

171

Carbanionic Phosphoylide Dianion

Sarah B. J. Dane, Vesal Naseri and Dominic S. Wright (sbjd2@cam.ac.uk)

University of Cambridge, UK Phosphorus ylides (Fig 1A) have become a classical tool for organic synthesis ever since the discovery that they could be used for olefination reactions by Wittig. Schildbauer [1] has extensively studies these as ligands but one elusive member of this family are dianions of the type [RP(CH2)3]2- (Fig 1A), recently it has become possible to prepare and characterise them.

Figure 1: (A) the structure of a classical phosohprus ylide. (B) the stutrure of [RP(CH2)3]2- type dianions, (C) Isoelectronic p-block element imido and oxo-anions, isoelectronic with [RP(CHR')3]2- dianions. Our interest in the phosphoylide dianions [RP(CHR')3]2-, arises from their being valence-isoelectronic with a broad family of tripodal p-block element imido ligands of the type [RmE(NR)3]n- (Figure 1C), whose coordination chemistry has been investigated extensively in the past few decades. They are also isoelectronic with important classes of phosphorus oxo-anions, such as phosphonate anions [RPO3]2-, which have broad applications in the synthesis of framework materials. DFT calculations show that [RP(CHR`)3]2- are both σ-donors and π-acceptors: the σ-donor character is via the lone pairs on the CH2 groups and the π-acceptor character is via the vacant σ* orbital of the P-C(R) bond. Reacting the phosphonium salt [PhP(CH3)3][I] with 3 eqv of tBuLi in thf gives [Li2{PhP(CH2)3}.2THF]2 (1) (Fig 2A). Transmetallations with Fe2I produced the hydride complex [{PhP(CH2)3Fe}4(µ4-H)]-.Li(thf)4

+ (2) (Fig 2B), a rare example of a [metal]4[µ4-H] compound.[2]

Figure 2: (a) Structure of (1) [Li2{PhP(CH2)3}.2THF]2, (b) The tetranuclear hydride comples [{PhP(CH2)3Fe}4(µ4-H)]-.Li(thf)4

+ (2) [1] W.C. Kaska, Coordination Chemistry Reviews, 1983, 48, 1-58 [2] Robert J. Less, Vesal Naseri, Dominic S. Wright, Organometallics, 2009, 13, 3594-3596

A B

Poster 84