Indian Journal of Chemistry Vol. 42A . January 2003, pp. 48-52

One-dimensional infinite chain organotin complexes: Synthesis and structural characterization of triphenyltin(IV) thiophen-2-carboxylate and triphenyltin(IV)

4-pyridinylcarboxylate

Handong Yin*, Chuanhua Wang, Yong Wang & Chunlin Ma

Department of Chemistry, Liaocheng Teachers University, Liaocheng 252059, P R China

Received J 3 OClober 200 I ; revised 3 Seplelllber 2002

Triphenyltin(lV) thiophen-2-carboxylate (1) and triphenyltin(lV) 4-pyridinylcarboxylate (2) have been synthesized by the react ion of sodium 2-thiophenylcarboxylate and sodium 4-pyrid inylcarboxylate with the triphenyltin(l V) chloride and characterized by lR, 'H NMR. MS and sing le crystal X-ray diffraction. In the crystals of 1, the tin atoms are rendered four-coordinated in a di storted tetrahedral structure. Due to the presence of a close intermolec ular Sn "'S interact ion of 3.339 A. the structure can be described as a weak ly-bridged one-d imensional chain polymer. In the crystal s of 2, the tin atom is fi ve-coordinated with bridging pyridine N atom and resulting struct ure is one-dimensiona l chain polymer.

Organotin(lV) carboxylates are widely used as biocides, fungicide and in industry as homogeneous catalysts '-) . In order to study the relationship between biological activity and structure, a number of investi gations of such molecules have been reported in recent years. Studies on organotin complexes having carboxylate ligands with additional donor atoms, such as a nitrogen, available for coordination to tin atom, has revealed new structural types which may lead to complexes with di fferent activity. For example, dimethyltin 2-pyridinylcarboxylate4 has seven-coordinated tin atom, owing to the multi dentate nature of the bridging 2-pyridinylcarboxylate ligand which utilizes both the carboxylate 0 and the pyridine N atoms in coord ination to Sn. In contrast, dimethyl 2-furanylcarboxylate and diethyl 2-thiophenyl-carboxylate have six-coordinated tin centers5. As an extension of our studies of organotin carboxylate with additional donor atoms residing on the carboxylate ligand, we now report the synthesis and st ructure of triphenyltin(lV) thiophen-2-carboxylate (1) and tri pheny Itin(l V) 4-pyridiny Icarboxylate (2) .

Materials and Methods Al l reactions were carried out under nitrogen

atmosphere using standard Schlenk technique. Benzene was distilled under nitrogen in the presence of sodium and benzopenone before use. IR spectra were recorded with a Nicolet-460 spectrophotometer, as KBr discs. I H NMR spectra were recorded on Jeol-FX-90Q NMR spectrometer, chemical shifts are given

in ppm relative to Me4Si in CDCl" solvent. Elemental analyses were performed in a Carlo-Erba 1106 elemental analyzer, Tin was estimated as Sn02. The mass spectra were recorded on a HP-5988A spectrometer operati ng at 70 e V.

Synthesis of(1) and (2) Anhydrous sod ium 2-thiophenylcarboxylate or

sodium 4-pyridinecarboxylate (1.2 mmol) was added to a benzene ( 10 mL) solution of Ph ,SnCI ( 1.0 mmol ) and stirred for 15 h at 40°C. The precipitaled salts were removed by fi ltration . The solvent was removed gradually by evaporation under vacuum until solid products were obtained. The products were recrystallized from CH2CI2-C6H 14 to give a colorless crystals.

Triphenyltin(lV) thiophen-2-carboxylate (1): Yield 0.429 g (90%), m.p. 88-90°C Anal. Found: C, 57.68; H, 3.72; S, 6.84 Sn, 24.59. Calc. For C2j HIS0 2SSn: C, 57.90; H, 3.80; S, 6.72; Sn, 24.88. TR(KBr) : u(Ar-H ) 3064, 3043, uas(COO) 1623 , us(COO) 1326, u(Sn-C) 547, u (Sn-O)443 cm-I. IH NMR (CHCI» : 7.36-7 .79 (l8H, m, Ph-H, thiophene-H). mlz: 405 (M+ -C6H6-H. 11.5%), 351 (Ph)Sn+, 100%), 27 3 [(C6H4h Sn+H, 9.8%], 127 (C4H3SC02+, 5.4%), 120 (Sn+, 45.4 %).

Triphenyltin(lV) 4-pyridinylcarboxy late (2): Yield 0.453 g (85%), m.p. 205-206°C. Anal. Found: C 57.30, H 3.85, N 2.8 1, Sn 23.33 . Calc. for C24.5 H2oCIN02Sn C 57.19, H 3.92, N 2.72, Sn 23.07. IR(KBr): u(Ar-H) 3065, 3040, uas(COO) 1646, us(COO) 1329, u(Sn-C)544, u(Sn-N)498, u(Sn-O)4SS

YIN et al.: ONE-DIMENSIONAL INFINITE CHAIN ORGANOTIN COMPLEXES 49

cm· l . IH NMR (CHCI): 8.80 (2H, d, 2, 6-pyridine-H), 7.80 (2H, d, 3, 5-pyridine-H), 7.36-7.72 (15H, m, ph-H) . m/z:400 (M+-C6H6-H, 8.5 %), 351 (Ph)Sn+, 100%), 273 [(C6H4hSn+H, 6.4 %], 122 (C5H4NC02+, 3.2%), 120 (Sn+, 45.4%).

Crystal structure The X-ray diffraction experiments for

triphenyltin(lV) thiophen-2-carboxylate (1) and triphenyltin(lV) 4-pyridinylcarboxylate (2) were made on a Bruker Smart 1000 CCD diffractometer with graphite monochromated MoKa (A,=O.71 073 A) radiation . The structure was solved by direct method and expanded method using Fourier techniques with Shelxl-97 program. The non-hydrogen atoms were refined an isotropically by full-matrix least-squares calculations. Crystallographic data for 1 and 2 are li sted in Table I.

Results and Discussion The crystal structure and stereogram of the

complexes 1 and 2 packing in a crystal unit cell are shown in (I) and (II) respectively. Selected bond distances and angles are listed in Tables 2 and 3.

The basic structure of the complex 1, resu lts from a distortion from tetrahedral geometry induced by the approach of an oxygen atom, 0(2), of the carboxylate group at a tetrahedral face opposite one of the tin phenyl groups. The distortion is toward a trigonal bipyramid that contains 0(2) and the latter phenyl group at axial sites [Structure (I)]. The axial

(I)

Table I-Crystallographic data for triphenyltin(IV ) thiophen-2-carboxylate (1) and triphenyltin(lV) 4-pyridinylcarboxylate

(2)

Crystal data 1 2

Molecu lar formul a C23HIs0 2SSn C2oH2oCIN02Sn Formul ar weight 477. 12 514.55 Crystal system Monoclinic Monoc linic Space group P2 1/n P2 1 Unit cell dimensions a(A) 13.429(7) 12.269(3) b(A) 11.1773(6) 14.987(4) c(A) 14.241(8) 24.3 18(7) j3( ) 11 6.5 19(6) 90.040(5) V(A3) 2014.6(18) 4471 (2) Z 4 8 Dc, I(Mg/m

3) 1.573 1.529

J1 (mm· l ) 1.386 1.282 F (000) 952 2056 Crystal size (mm) 0.50xO.40xO.20 0.40xO.30xO.20 Theta range/o 2.36::::11::::25 .03 1.60::::11::::25.03 Observed/cut-off 3544/20(1) 14 770120( I) Rint 0.0548 0.0404 R/wR2 0.039110.0943 0.0543/0.1086 Largest difference 0.402/-0.517 0.927/-0.679 Peak and hole (e·k3)

Sn(l ) ·0(2) (2 .774 A) length is considerably longer than the equatorial Sn(l )-0(1) (2.081 A) bond length. On the basis of such interaction, the O( I )-Sn( I )-C(6) (94.32°) angle significantly deviates from the ideal tetrahedral angle. However, other angles around the central Sn atom are comparable to tetrahedral angle. Due to the presence of a close intermolecular SnS interaction of 3.339 A, the structure can be described as a weakly-bridged one-dimensional chain polymer.

50 INDIAN J CHEM, SEC A, JANUARY 2003

Table 2-Selected bond distances (A) and angles n for complex 1 Sn( I )-O( I ) 2.08 1 (3) Sn(l) 0(2) 2.774 Sn( I )-C( 18) 2. 120(4) Sn(I)-C(12) 2.124(4) Sn( I )-C(6) 2.126(4) Sn( I )S (1)# 3.339 S( I )-C(5) 1.671 (6) S(I )-C(2) 1.699( 4) O( I )-C( I) 1.309(5) O(2)-C(l ) 1.223(5) C(I )-C(2) 1.466(6) C(2)-C(3) 1.07(6)

O( I )-Sn( I )-C( 18) I 08.35( I ) O( I )-Sn( I )-C( 12) 109.25( 14) O( I )-Sn( I )-C(6) 94.32( 13) C( 18)-Sn( I )-C( 12) 117.86(1 ) C( 18)-Sn( I )-C(6) 113.52( 16) C( 12)-Sn( I )-C(6) 110.87( 15) C(5)-S( I )-C(2) 92.5(3) C( I )-O( I )-Sn( I ) 108.4(3) C( II )-C(6)-Sn(l ) 120.8(3) C(7)-C(6)-Sn( I ) 121.9(3) C( 17)-C( 12)-Sn( I ) 121.5(4) 0 (2)-C( I )-O( I) 121.9(4) 0(2)-C( I )-C(2) 123.0(4) O( I )-C( I )-C(2) 11 5. 1(4) C(3)-C(2)-S( I ) 111 .7(3) C( I )-C(2)-S( I ) 11 9.0(3) C(4)-C(5)-S( I ) 112.4(4) C( 13)-C( 12)-Sn( I) 120.3(3) C(23 )-C( 18)-Sn( I ) 12 1.5(3) C( 19)-C( 18)-Sn( I ) 119.5(3) C( 17)-C( 12 )-C( 13) 11 8.2(4) O( I )-Sn( I )0(2) 5 1.8(2) 0(2)' Sn( I )-C( 18) 85.2( I ) 0(2)Sn( I )-C( 12) 8 1.2(6) 0(2)Sn( I )-C(6) 145.9(2) 0(1 )-Sn(l ) · S ( 1)# 167.0( 1) C(1)-Sn( I ) 'S ( 1)# 72.6(8) C( 12)-Sn( I )S( 1)# 76.4(8) C( 18)-Sn(l ) S ( 1)# 77.7( 1) 0(2)Sn( I )S( 1)# 141.0(2)

Table 3--Selected bond distances (A) and angles (0) for complex 2

BOlld dis/{/Ilces

A B A B

Sn( I )-C(25) 2. 123( 11 ) 2. 11 6(1 1 ) Sn(2)-N( I ) 2.557(9) 2.553(9) Sn( I )-C( 19) 2. 130(11 ) 2. 117( 13) N(I)-C(4) 1.291( 13) 1.313( 13) Sn( I )-C( 13) 2. 132(12) 2. 145( 12) N( I )-C(5) 1.36 1 ( 14) 1.380( 15) Sn(I)-O( I ) 2. 170(7) 2. 173(7) N(2)-C( II ) 1.336( 13) 1.322( 13 Sn(I) .. . O(2) 3.082 3.054 N(2)-C(10) 1.371(13) 1.339( 14) Sn(2)-C(3 1) 2. 120( 13) 2. 126( 12) 0 (1 )-C( I ) 1.252( 13) 1.273( 13) Sn(2)-C(43) 2. 161(12) 2. 140( 14) O( I )-C(2) 1.1 96( I I ) 1.1 83( II ) Sn(2)-C(37) 2. 177( 11 ) 2.151 ( 12) O(3)-C(7) 1.278( 13) 1.285( 14) Sn(2)-0(3) 2. 148(7) 2.159(7) 0(4)-C(7) 1.236( 12) 1.222( 13) Sn(2) ... 0(4) 3. 106 3. 110 C( I )-C(2) 1.562( i 3) 1.507( 13) Sn( I )-N(2)# 2.60 1( 12) 2.584(9) C(2)-C(6) 1.400( 14) 1.408( 13)

BOlld allgles

C( 13)-Sn( I )-O( I ) 89 .1 (3) 88.4(3) C( 44 )-C( 43 )-Sn(2) 11 6.5(9) 118.3( 11 ) C(25)-Sn( 1 )-C( 19) 126.5(5) 126.7(5) C(4)-N( I )-C(5) 11 7.9(10) 116.4( 10) C(25)-Sn( 1 )-C( 13) 11 8.3(5) 11 8.7(5) C(4)-N( I )-Sn(2) 125.2(8) 125 .8(8) C( 19)-Sn( I )-C( 13) 11 3.2(5) 11 2.6(5) C(4)-N( I )-Sn(2) 11 6.7(8) 117.3(8) C(2S)-Sn( I )-O( I ) 96. 1 (3) 96.5(3) C( 11 )-N(2)-C( 10) 11 8.7(9) 120.9( I 0) C( 19)-Sn( I )-O( I ) 98. 1(3) 98.2(3) C( 13)-Sn( I )-N(2)# 84.6(9) 84.4(3) C(31 )-Sn(2)-0(3) 93. 1(4) 98.2(3) C(25)-Sn( I )-N(2)# 84.8(7) 84.8(4) C(3 1 )-Sn(2)-C( 43) 124.9(5) 123.8(5) C( 19)-Sn( I )-N(2)# 86.4(9) 87. 1(3) 0(3 )-Sn(2 )-C( 43) 96.5(3) 96.5(3) O( I )-Sn( I )-N(2)# 173.3(3) 172.6(3) C(31 )-Sn(2)-C(37) 122.9(5) 124.6(6) C( I 0)-N(2)-Sn( 1)# 11 6.8(5) 117.2(7) 0(3)-Sn(2)-C(37) 90.4(4) 89.6(4) C(lI)-N(2)-Sn( I )# 120.7(8) 12 1.9(8) C(43)-Sn(2)-C(37) 111.1 (5) 110.6(5) C( I )-O( I )-Sn( I ) 11 5.3(7) 116.0(7) C(31 )-Sn(2)-N( I ) 83.8(4) 83.8(4) C(7)-0(3)-Sn(2) 117.8(7) 116.0(7) 0(3)-Sn(2)-N( I ) 175.8(3) 176. 1(3) 0(2 )-C( I )-O( I ) 127 .3( 10) 124.2( 10) C(43)-Sn(2)-N( I ) 87.6(4) 87.4(4) O(2)-C(I )-C(2) 11 8. / ( II ) 120.3( I 0) C(37)-Sn(2)-N( I ) 88.9(4) 89.0(4) O( I )-C( I )-C(2) 114.5( II ) 11 5.5( 10) C( II )-N(2)-C( I 0) 11 8.7(9) 120.9(10) C(3)-C(2)-C(6) 119.9( 10) 117.2(9) C(3)-C(2)-C( I ) 122.0(10) 12 1.9(9) 0(4 )-C(7)-0(3) 124.4( I 0) 126.6( II ) N( I )-C(4)-C(3) 123.3( 11) 124. / ( 11 ) 0(4)-C(7)-C(8) 11 9.6( II ) 120.0( 12) N( I )-C(5)-C(6) 124.3( 12) 122.7( 11 ) 0(3)-C(7)-C(8) 11 5.9( 11 ) 11 3.4( II ) N(2)-C( 10)-C(9) 11 9.5(9, 11 9.9( 10) C( 14)-C( 13)-Sn( l ) 120.5(8) 120.2(9) N(2)-C( II )-C( 12) 123.2(1 1) 12 1.0( 11 ) C( 18)-C( 13)-Sn( I ) 11 9.3(9) 120.2( I 0)

C(20)-C( 19)-Sn( I ) 11 6. / ( 10) 117.7(8) C(30)-C(25)-Sn( I ) 12/.8(8) 11 7.2( 10)

C(24 )-C( 19)-Sn( I ) 11 9.3(9) 12 1.4(9) C(26)-C(25)-Sn( 1) 11 8.0(9) 11 8.6(8) C(32)-C(3 1 )-Sn(2) 12 1.4( 10) 124. 1( 12) C( 42)-C(37)-Sn(2) 11 6.2(9) 11 5.2( 11 ) C(36)-C(3 1 )-Sn(2) 117. / ( II ) 11 8.5( I I) C(48)-C( 43)-Sn(2) 11 8.6( 10) 120.6( 11 ) C(38)-C(37)-Sn(2) 122. /(11 ) 121.3( I I)

YIN el al.: ONE-DIMENSIONAL INFINITE CHAIN ORGANOTIN COMPLEXES 51

From unit cell, it is found that complex 2 contains two independent molecules. A computer fitting of molecules A and B shows a very marginal difference in the orientation of molecular chains and relevant bond lengths and angles, and two kinds of tin atoms with different chemical environment can be found in the molecule A or B. The molecule A or molecule B of crystal 2 unit cell possesses an unequivocal polymeric structure, but this structure differs from the tributyltin 2-(5-tert-butyl)furanylcarboxylate6 and tri benzy I ti n 2-(5-tert -buty I )furany Icarbox y late6. Each tin atom is rendered five-coordinated in a trigonal bipyramidal structure by coordination of the nitrogen atom of 4-pyridinylcarboxylate group from an adj acent molecule. The central tin atoms are surrounded axially by one oxygen, one nitrogen atoms and equatorially by the three carbon atoms of the phenyl groups. The intramolecular Sn( I )-0(1), Sn(2)-0(3), Sn(3)-0(5) and Sn(4)-0(7) bond distances are 2. 170(7) A, 2.173(7) A, 2.148(7) A and 2.159(7) A which are longer than that in {["Bu2Sn(2-pic)hO} / (2.0544 A and 2.1 IO A), but shorter than that in

o 0 8 Me)Sn02CCsH4N' H20 (2. 18 A and 2.21 A). The Sn( I )-0(2) , Sn(2)-0(4), Sn(3)-0(6) and Sn(4)-0(8) di stances are 3.082 A, 3.054 A, 3.106 A and

(II)

3.110 A, respectively and are larger than the sum of the covalent radii for Sn and 0 of 2.07 A. It is shown that the 0(2), 0(4), 0(6) and 0(8) atoms do not make any significant contact with the Sn atom. The Sn( 1)-N(2)#, Sn(2)-N(1), Sn(3)-N(4)# and Sn(4)-N(3) bond distances are 2.601(12) A, 2.557(9) A 2.584(9) A and 2.553(9) A, respectively which are larger than the sum of the covalent radii of Sn and N(2 . 15 A) , but considerably less than the sum of the Van der Waals radii (3.75 A) and should be considered as a bonding interaction.

In complex 2 the distortions from true tri gonal bipyramidal symmetry are reflected in the interatomic angles. For instance, around the Sn(2) atom o f molecule A the angles of 0(3)-Sn(2)-C(3I)l93.1 (4 t ] and 0(3)-Sn(2)-C(43)[96.5(3n are greater than 90°, and only 0(3)-Sn(2)-C(37) [90.4(4n approximates to 90°. In contrast, the angles C(31 )-Sn(2)-N(1 )[83.8(4 )0], C( 43)-Sn(2)-N(1 )[87 .6( 4 )0] and C(37)-Sn(2)-N(l)[88.9(4)0] are all less than 90°. The angle 0(3)-Sn(2)-N(1) [175.8(3n shows that the atoms 0(3), Sn(2) and N( I) are nearly linear. Other tin atoms are similar to Sn(2) atom. All are disto rted trigonal bipyramidal structure.

52 TNDIAN J CHEM, SEC A, JANUARY 2003

The assignment of IR bands of triphenyltin(lV) thiophen-2-carboxylate (1) and triphenyltin(lV) 4-pyridinylcarboxylate (2) have been made by comparison with the IR spectra of the related sodium 2-thiophenylcarboxylate, sodium 4-pyridinyl-carboxylate and Ph3SnCI. The difference flv of U,.,(coo) and u£coo) is important since these frequencies can be used for determining the type of bonding between metal and carboxyI3,9, The flv [uas(coo)-us(coo)] values of 297 cm- I and 317 cm- I for complexes 1 and 2 respectively strongly indicate the unibidentate chelating of the carboxylate groupIO,II,

The bands in the region 443 and 455 cm- I are assigned to v(Sn-O), The IR spectra of complex 2 at 498cm- 1 exhibit U Sn.N confirming that the N hetero atom in the pyridine group coordinates to tin atom 12,

In mass spectra, the molecular ions were not detected for complexes 1 and 2, M+-C6H6-H and C6H4h Sn+H were the main tin-containing fragment. The most abundant ions were Ph3Sn + (mJz = 351). Ions of mass higher than parent species were not detected nor were there fragments containing more than one tin atom. This indicates that inter-molecular Sn ' S or Snf-N bond has been broken up, and the complexes take only monomeric structure in gaseous state.

Acknowledgement We acknowledge the Financial support of the

Shandong Province Science Foundation , and the State Key Laboratory of Crystal Materials, Shandong University, P R China,

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