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CHEM 232 Inorganic Chemistry II (Spring 2006)

Instructor: Wa-Hung Leung (ext. 7360, chleung@ust.hk) Office: Rm 4528 (Lift 25/26), Lab: Rm 7141

TAs: (1) Zhang Li (chzhl@ust.hk) (2) Yi Xiaoyi (xyyi@ust.hk) (3) Wong Wang Yee (chyee@ust.hk) (4) Au Yeung Siu Fung (alexwill@ust.hk)

Class schedule:Lecture: Mon/Wed/Fri, 13:00-13:50 (Rm 2464)Tutorial/example class (4) : To be confirmed

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Course ContentsCourse Contents1. Coordination Chemistry

Crystal field theorySpectral, magnetic, thermochemcial propertiesCoordination equilibria, chelate effect

2. Organometallic chemistry18 e rule, Carbonyl, olefin, cycloolefin compounds, Organometallic reactions, homogeneous catalysis

3. Main group chemistryHydride and alkyl compoundsElement-element multiple bondsInorganic rings and cagesSilicates and aluminosilicates

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Assessment scheme

Attendance of lectures and

Quizzes (4) 8% Assignments (2) 2x4% Mid-term exam (~ week 8/9) 38% Final exam 40% Tutorials (4) and others 6%

• Check out a PRS handset!

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Textbooks and references booksTextbook: “Inorganic Chemistry” by C. E. Housecroft and A. G. Sharpe, Pr

entice Hall (1st ed., 2001; 2nd ed., 2005)

Other suggested readings: Inorganic Chemistry, 3rd ed., by D. F. Shriver et al., OUP (1999).

Basic Inorganic Chemistry, 3rd ed., by F. A. Cotton et al., Wiley (1995)

Concepts and Models of Inorganic Chemistry, 3rd ed., by B. Douglas et al., Wiley (1994)

Inorganic Chemistry, 3rd ed., by G.L. Miessler and D.A. Tarr, Prentice Hall (2004)

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Websites Course homepage: http://webct.ust.hk

Useful links• Department of Chemistry: http://www-chem.ust.hk/

• Textbook website: www.pearsoned.co.uk/housecroft

• Periodic table: For example,http://www.webelements.com/http://www.rsc.org/is/viselements.htmhttp://pubs.acs.org/cen/80th/elements.html

Conduct in classroom: http://www.ust.hk/vpaao/conduct/con_classroom_Aug04.ppt

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Coordination Chemistry

• Ref.: Housecroft (Chap. 20), Shriver (Chap. 7)• Introduction: the metals and ligands• Crystal field theory: octahedral, tetrahedral, and squ

are planar geometry• Spectrochemical series (strong/weak field ligands)• Electron configurations: LFSE, LS and HS config.• Spectral, magnetic and thermochemical properties• Coordination equilibria, chelate effect• M.O. diagram of ML6

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LM

L L

L

L

L

n+

Metal

Ligand

n X

Counter anion

Coordination compounds (metal complexes)

L

ML L

L

MLL L

L

ML

L L

L

L

L MLL

L

L

ML

L L

L

L

L

Tetrahedral

Square planar

Square pyramidal

Trigonal bipyramidal

Octahedral

Common geometry

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The metalsTransition elements (http://www.rsc.org/is/viselements.htm) Elements with incomplete d shell

(A) Position First/ second/ third row TMs Size decreases down a group Lanthanide contraction (filling of f orbitals)

Sizes of 2nd row and 3rd row TMs are similar

Ion Cr3+ Mo3+ Ru3+ Ir3+

Size/Å (CN = 6) 0.76 0.83 0.82 0.82

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(B) Early/late TMsEarly: on the LHS of the periodic table (e.g. Ti)Late: on the RHS of the periodic table (e.g. Pt)

Usually, for metal complexes Early TM : high metal oxidation state, e.g. Ti(IV), V(V)

(high valent); hard metal ions (binds to hard ligands)

Late TM : low metal oxidation state, e.g. Pt(II), Au(I) (low valent); soft metal ions (binds to soft ligands)

Why?

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Atomic number

Atomic radius

Ti

Cu

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Atomic number

IE

Ti

Cu

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Ligands

(A) Charge (formal charge)• Neutral (e.g. :CO, :PR3, :NH3)• Anionic (e.g. Cl-, O2-, CH3

-)• Cationic (rare!) (e.g. NO+, C7H7

+)

(B) Hard/Soft propertiesHard : period 1 donor (NH3, OH2)Soft : carbon (CO, CH3

-, CH2=CH2) & period 2 donors (PR3, SR2)

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(C) No. of donor atom

NH3 NH2CH2CH2NH2 NH(CH2NH2)2

unidentate bidentate tridentate

ammoniaor ammine

ethylenediamine(en)

diethylenetriamine(dien)

N N N N N N

pyridinepy

2,2'-bipyridinebipy

2,2':6',6"-terpyridineterpy

Metal complexes with polydentate (chelating) ligands are more stable than those with unidentate analogues.

Chelate effect

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(ii) acceptors ( acids)

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Exercises

Classify the following ligands as donor, acceptor, or ligands

• NMe3

• I-

• NO+

• CN-

• OH-

• H-

• CH3-

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Nomenclature

(1) Ligands in alphabetical order(3) Indicate O.N. of metal (in Roman no.: I, II, 0)(4) Indicate the no. of L and M (di, tri, tetra etc.).

Also bis, tris, tetrakis(5) Anionic ligand o;

e.g. Cl- (chloro), H- (hydrido), CN- (cyano) (6) Anionic complexes => atee.g. Mn (manganate), Fe (ferrate), Cr (chromate) etc

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ML

LL

ML

L

LM

L

L

ML

L

trans cis fac mer

(7) Add structural prefixes, e.g. cis/ trans, fac/ mer etc.

Examples: K3[Mn(CN)6] Tripotassium hexacyanomanganate(III)Na2[Fe(CO)4]Disodium tetracarbonylferrate(-II)

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ExercisesName the following compounds (1) [Mn2(CO)10], [Co2(CO)8]

(2) [Ru(PPh3)4Cl2]

(3) K2[Pt(CN)4]

(4) [Cr(NH3)3(H2O)(OH)Cl][NO3]