Synthesis and characterization of diorganotin(IV) dichloride adducts of Schiff bases

Four diorganotin(IV) dichloride adduct complexes, Me2SnCl2(HL)(2) and Ph2SnCl2(HL)(2), derived from bidentate N-substituted salicylideneimine ligands, HL [o-HOC6H4CH=NC6H4R-4; R = Me, Cl, OMe] have been synthesized by the reaction of dimethyl- or diphenyltin(IV) dichloride with the respective Schiff bases in refluxing ethanol and characterized by IR, NMR (H-1, C-13, Sn-119) spectroscopy and elemental analysis. The molecular structure of Me2SnCl2(HOC6H4CH=NC6H4Me-4)(2) in is determined by single crystal X-ray diffraction. The structural analysis reveal that two crystallographically independent molecules reside on centres of symmetry. The tin atoms display all-trans octahedral coordination, the two Schiff base ligands being O-bonded as iminium phenolate zwitterions. Solution NMR studies indicate similar coordination for all the four compounds.