Transition metal quinone-thiosemicarbazone complexes 1: Evaluation of EPR covalency parameters and redox properties of pseudo-square-planar copper(II)-naphthoquinone thiosemicarbazones

EPR studies on pseudo-square-planar copper(II) complexes of naphthoquinone-thiosemicarbazones of the formula [CuLCl] reveal appreciable covalency in the metal-ligand bonding as a consequence of extensive delocalization, while cyclic voltammetric response of these complexes suggests metal-centered redox behavior. There exists a linear relationship between the degree of tetrahedral distortion f(α) with EPR and redox parameters.