Synthesis & characterisation of copper(II), nickel(II), cobalt(II) & dioxouranium(VI) complexes of a new series of tetradentate binucleating schiff base ligands

Abstract

A new series of binucleating tetradentate ligands, Sal-dadpmX, and complexes of the type M₂(SaldadpmX)₂ have been synthesised and characterised by elemental analysis, spectral, magnetic and thermal studies, where Sal-dadpmX refers to 3,3'-di(X)-substituted-4,4'-bis(salicylideneimino)diphenylmethane (X=H, CH₃, OCH₃, Cl) and M=Cu(II), Ni(II), Co(II) and dioxouranium(VI). The results indicate a binuclear structure for Cu(II) complexes with pseudo-tetrahedral geometry and polynuclear structures for Ni(II), Co(II) and dioxouranium(VI) complexes with near octahedral geometry. The two Cu(II) centres of Cu₂(Sal-dadprnX)₂ exhibit one step two-electron cyclic voltammetric responses due to Cu(II)/Cu(I) at ~ - 0.35V and Cu(II)/Cu(III) at ~ + 0.45V (vs SCE).