Studies in aryltin chemistry: III. Crystal and molecular structures of tetra( p-methoxyphenyl)tin(IV) and tetra( p-methylthiophenyl)tin(IV)

Abstract

Tetrakis( p-methylthiophenyl)tin(IV) ( A) and tetrakis( p-methoxyphenyl)tin(IV) ( B) have been prepared and their vibrational spectra (400-100 cm −1) and X-ray crystal structures are reported. Both compounds are tetragonal with space group I 4 , Z = 2. For ( A), a = b = 13.553(4), c = 7.442(2) Å, and for ( B), a = b = 14.180(4), c = 6.303(2) Å, both at 173 K. Both structures were solved by the direct method and refined by full-matrix least squares calculations to R = 0.040, 767 observed reflections for A, and to R = 0.019, 721 observed reflections for B. Both molecules have 4 molecular symmetry with the CH 3S or CH 3O groups in the all- exo conformation almost coplanar with the phenyl rings. Increasing size of the para-substituent as CH 3 is replaced by CH 3O and then CH 3S causes a decrease in d(SnC) from 2.147(6) to 2.136(4) and 2.123(7) Å ascribed to increased intermolecular repulsions in these isomorphous close-packed structures.