Synthesis, Characterization, and Electrochemical Study of Complexes with 4,4′-Bis(Salicylideneimino) Diphenylether and Cobalt(II), Copper(II), Zinc(II), and Cadmium(II)

Abstract : The 4,4′-bis(salicyleneimino) diphenyl ether is a N2O3 Schiff base but it acts as a tetradentate ligand. Its complexes with cobalt (II), copper(II), zinc(II), and cadmium (II) were characterised using spectroscopic determinations, d.s.c. and cyclic voltammetry. In these compounds, the coordination occurs through the non-ionised phenolic hydroxyl of the ligand and the nitrogen atom of the azomethine moiety. These new complexes should be formulated [CuCl2(H2L)] · H2O, [(CoCl2)2(H2L)(H2O)4] · 2H2O, [Zn2Cl2(H2L)] and [Cd(H2L)]Cl2 respectively. The copper(II) and cadmium(II) complexes are mononuclear while the cobalt(II) and zinc(II) appeared to be binuclear species. The anodic oxidations of cobalt (II), zinc(II), and cadmium(II) compounds show only one peak attributed to the oxidation of the phenolic moiety of the ligand. In addition, the copper complex [CuCl2(H2L)] · H2O exhibits two peaks at +680 mV (ECS) and +965 mV (ECS) corresponding to the complexed couples CuII/CuIII and CuI/CuII.