Binuclear Complexes of Diphenyltin(IV) with Salicylaldimine Ligands: Synthesis, Structures, and Electrochemical Properties

Abstract

New binuclear tin(IV) complexes are prepared by the condensation of diphenyltin oxide Ph₂SnO with a number of Schiff bases based on salicylaldehyde. The structures of the complexes are confirmed by ¹Н, ¹³С, and ¹¹⁹Sn NMR spectroscopy and X-ray diffraction analysis (CIF file CCDC no. 2433411). The study of the complexes by UV spectroscopy shows that all absorption bands of the ligands experience a bathochromic shift upon complex formation with the metal fragment. The ability of the complexes to undergo electrochemical transformations is studied by cyclic voltammetry. In all cases, the oxidation and reduction of the complexes are irreversible. For the complexes with the conjugated bridge, two coordinated phenolate groups of the ligands are oxidized simultaneously at the same potential, whereas the complex with the unconjugated adipine bridge exhibits two peaks at different potentials on the oxidation curve, which is probably related to the fact that two different “ends” of the molecule are oxidized at different potentials.