Electrochemical Synthesis and Characterization of Tin(IV) Complexes of Dianionic Terdentate Schiff Base Ligands

Tin(IV) complexes of the series of dianionic terdemate Schiff bases N-[(2-pyrroyl)methylidene]-N'-tosylbenzene-1,2-diamine, (H2L1), N-[(2-hydroxyphenyl)methylidene]-N'-tosylbenzene-1,2-diamine (H2L1) and some R substituted 2-{/(2-hydroxyphenyl)imino/methyl}phenols [R = H (H2L3), 4,6-(OCH3)(2) (H2L4), 3-(OC2H5) (H2L5) and 3,5-Br-2 (H2L6)] have been synthesized. The compounds were obtained by the electrochemical oxidation of a tin anode in a cell containing an acetonitrile solution of the corresponding ligand. The complex [SnL21] was also obtained by reaction of SnCl(2)(.)2H(2)O and H2L1 in methanol in the presence of triethylamine. The crystal structure of the ligand [H2L6] and the complexes [SnL21] (1), [SnL22] (2), [SnL23] (3) and [SnL26] (6) were determined by X-ray diffraction. In the complexes, the tin atom is in an octahedral environment coordinated by two dianionic terdentate ligands. Spectroscopic data for the complexes (IR, I-1 and Sn-119 NMR and mass spectra) are discussed and related to structural information.