Synthesis and spectroscopic properties of [N-(4-carboxyphenyl) salicylideneiminato] di- and tri-organotin (IV) complexes and crystal structures of {[nBu2Sn(2-OHC6H4CHNC6H4COO)]2O}2 and Ph3Sn(2-OHC6H4CHNC6H4COO)

Reactions of R2SnO (R: nBu, Cy, Ph, PhCH2) and R3SnCl (R: Ph, Cy, PhCH2, 2-Cl-PhCH2, 4-F-PhCH2, 4-Cl-PhCH2) with N-(4-carboxyphenyl)-salicylideneimine (LH2) in 1:1 stoichiometry afford complexes {[R2Sn(LH)]2O}2 and R3Sn(LH). These complexes have been characterized by elemental analyses, IR, 1H and 119Sn NMR spectroscopy. The crystal structures of {[nBu2Sn(LH)]2O}2, 1 and Ph3Sn(L), 5 are determined by single crystal X-ray diffraction. Results showed that in the solid state the complex 1 is a tetranuclear centrosymmetric dimer with six-coordination being assigned to both the endo-cyclic and exo-cyclic tin atoms after consideration of close intermolecular tin oxygen contacts, and study show that the imino nitrogen atom do not participate in coordination to the tin atom. The complex 5 is a monomer, and in the molecule the tin atoms are five-coordinated in trigonal bipyramidal geometries with the two oxygen atom of the carboxylate both coordinating to the tin atoms.