Symmetry of the co-ordination sphere of di-n-butyltin(IV) in complexes with sulfanylcarboxylic acids

Four di-n-butyltin(IV) complexes have been prepared with sulfanylacetic, 2-sulfanylpropionic, sulfanylsuccinic and 2,3-disulfanylsuccinic acid, using two different procedures. The compounds were characterised by elemental analysis, Fourier-transform, Raman, 119 Sn Mössbauer, 1 H, 13 C and 119 Sn NMR spectroscopy. The IR and Raman data indicate the presence of bidentate carboxylate groups, non-linear C–Sn–C bonds, and Sn–S bonds. The results of Mössbauer spectroscopic measurements, based on point-charge model calculations, have shown the general occurrence of trigonal-bipyramidal environments at tin(IV). The multinuclear NMR studies also suggested the {O,S} co-ordination of the di-n-butyltin(IV) fragment, within the cyclic oligomeric complexes.