Synthesis and spectroscopic properties of [N-(4-carboxyphenyl) salicylideneiminato] di- and tri-organotin (IV) complexes and crystal structures of {[Bu2Sn(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.