The synthesis, NMR (¹H, ¹³C, ¹¹⁹Sn) and IR spectral studies of some di‐ and tri‐organotin(IV) sulfonates: X‐ray crystal structure of [(n‐C₄H₉)₂Sn(OSO₂C₆H₄CH₃‐4)₂·2H₂O]

Abstract

A number of alkyltin(IV) paratoluenesulfonates, R n Sn(OSO 2 C 6 H 4 CH 3 -4) 4−n (n = 2, 3; R = C 2 H 5 , n-C 3 H 7 , n-C 4 H 9 ), have been prepared and IR spectra and solution NMR ( 1 H, 13 C, 119 Sn) are reported for these compounds, including (n-C 4 H 9 ) 2 Sn(OSO 2 X) 2 (X = CH 3 and CF 3 ), the NMR spectra of which have not been reported previously. From the chemical shift δ( 119 Sn) and the coupling constants 1 J( 13 C, 119 Sn) and 2 J( 1 H, 119 Sn), the coordination of the tin atom and the geometry of its coordination sphere in solutions of these compounds is suggested. IR spectra of the compounds are very similar to that observed for the paratoluenesulfonate anion in its sodium salt. The studies indicate that diorganotin(IV) paratoluenesulfonates, and the previously reported compounds (n-C 4 H 9 ) 2 Sn(OSO 2 X) 2 (X = CH 3 and CF 3 ), contain bridging SO 3 X groups that yield polymeric structures with hexacoordination around tin and contain non-linear C-Sn-C bonds. In triorganotin(IV) sulfonates, pentacoordination for tin with a planar SnC 3 skeleton and bidentate bridging paratoluenesulfonate anionic groups are suggested by IR and NMR spectral studies. The X-ray structure shows [(n-C 4 H 9 ) 2 Sn(OSO 2 C 6 H 4 CH 3 -4) 2 ·2H 2 O] to be monomeric containing sixcoordinate tin and crystallizes from methanol-chloroform in monoclinic space group C2/c. The Sn-O (paratoluenesulfonate) bond distance (2.26(2)Å) is indicative of a relatively high degree of ionic character in the metal-anion bonds.

Structural studies of diorganotin(IV) sulfonates: The synthesis of [(n-C4H9)2Sn{OSO2C6H3(CH3)2-2,5}2] and [(n-C4H9)2Sn{OSO2R)2·2(hexamethylphosphoric triamide)] [R=CH3, 4-C6H4CH3, 2,5-C6H3(CH3)2, 2,4,6-C6H2(CH3)3] and crystal structures of [(n-C4H9)2Sn(μ-OH)(OSO2C6H3(CH3)2-2,5)]2 and (n-C4H9)2Sn{OSO2R)2·2(hexamethylphosphoric triamide)] [R=4-C6H4CH3, 2,5-C6H3(CH3)2, 2,4,6-C6H2(CH3)3]

“…Our studies [5,6] with ligands like (2,4,6,-C 6 H 2 (CH 3 ) 3 SO 3 Þ À , (4-C 6 H 4 CH 3 SO 3 Þ À and (CH 3 SO 3 Þ À and by others [7] also vouch for this observation. To probe deep into the nature of the product formation and to augment the hypothesis that RSO À 3 (R = non-fluorinated alkyl or aryl group) is indeed weakly coordinating, we synthesized a number of di-n-butyltin(IV) sulfonate: (n-C 4 H 9 ) 2 Sn{OSO 2 C 6 H 3 (CH 3 ) 2 -2,5} 2 (1) and [(n-C 4 H 9 ) 2 Sn{O-SO 2 R) 2 Á 2HMPA] [R = CH 3 (3) , 4-C 6 H 4 CH 3 (4), 2,5-C 6 H 3 (CH 3 ) 2 (5), 2,4,6-C 6 H 2 (CH 3 ) 3 (6)] and investigated the X-ray crystal structures of [(n-C 4 H 9 ) 2 Sn{(l-OH)(OSO 2 C 6 H 3 (CH 3 ) 2 )}] 2 (2) and (n-C 4 H 9 ) 2 -Sn{OSO 2 R) 2 Á 2HMPA [R = 4-C 6 H 4 CH 3 (4), 2,5-C 6 H 3 (CH 3 ) 2 (5), 2,4,6-C 6 H 2 (CH 3 ) 3 (6)].…”

“…The observed integral ratios of these groups support the composition of compounds 1-6. The 119 Sn NMR shifts recorded for 1 and 2 in CDCl 3 /DMSO-d 6 show a sharp peak at d = À337.2 and-119.2 ppm, respectively. The d value for 1 falls within the region (À210 to À400 ppm) generally assigned to indicate 6-coordinate Sn, while the value for 2 suggests 5-coordinate Sn consistent with the range (À90 to À190) generally observed in di-n-butyltin(IV) compounds [16].…”

“…These compounds exhibit a wide variety of associated structures, primarily attributed to the multidentate nature of the sulfonate anions and display supramolecular assemblies in solid state that are generated through extensive hydrogen bonding using one or more O donor atoms [3][4][5][6][7][8][9][10][11][12]. X-ray studies on diorganotin(IV) bis(alkyl or arylsulfonate) [R attached to sulfonate = CH 3 , 4-C 6 H 4 CH 3, 2,4,6-C 6 H 2 (CH 3 ) 3 ] have revealed weak coordination of the sulfonate anions to the central tin atom [5][6][7][8][9][10][11][12]. The bond distances between tin and the sulfonate oxygens are observed to be longer than the normal Sn-O distance of 2.14 Å, and fall in the range 2.20-2.78 Å, indicating a fair degree of ionic character associated with this coordinate bond.…”

The structure–activity relationship of some hexacoordinated dimethyltin(IV) complexes of fluorinated β‐diketone/β‐diketones and sterically congested heterocyclic β‐diketones

“…The 119 Sn NMR spectra of complexes 4 , 7 and 9 each exhibit two signals at −318.95, −326.04; −316.10, −323.68; and −316.19, −323.58, respectively. 119 Sn NMR chemical shift values reveal the presence of hexacoordinated tin centres in these dimethyltin(IV) complexes . These complexes may exist as geometrical isomers.…”

“…In these complexes, aromatic protons appear as a complex pattern in the region 7.18–8.12 ppm and the methyl protons directly attached to tin atom are observed as singlet in the region 0.94–1.02 ppm with well‐defined satellites. The value of coupling constant 2 J ( 119 Sn– 1 H) calculated from the tin satellite is found to be in the region 49 to 54.5 Hz . With the help of the Lockhart and Manders equation the CSnC bond angles can be calculated using 2 J ( 119 Sn– 1 H) values.…”