Some new butylthiobenzoatotin(IV) compounds: spectral studies and analysis of ligand's bonding

Five new monorganotin(IV) compounds with thiobenzoate ligand, [BuSn(SOCPh)2]2O (1), [BuSn(O)(SOCPh)]2 (2), BuSn(Cl)(SOCPh)2 (3), BuSn(Cl)2(SOCPh) (4) and [BuSn(OH)(Cl)(SOCPh)]2 (5) were synthesized and characterized by elemental analyses, IR, 1H and 13C NMR spectroscopy. 119Sn NMR spectroscopy was used to determine the coordination geometry around Sn(IV) in the cases of 2 and 4. 1, 2 and 5 are dimeric while 3 and 4 are monomeric. In all these molecules the thiobenzoate ion is coordinated only through its sulfur atom. Molecular structures of the compounds have been optimized by MM2 calculations. Semi-empirical quantum mechanical calculations (PM3 method) were performed to explain the monodentate-bonding pattern of thiobenzoate ligand.