Synthesis and characterization of bidentate mixed ligands of copper(II) complexes

Mixed ligand transition metal complexes play a significant role in biological processes by interacting with small molecules and activating the enzymes for nuclease activity. Two mixed ligand copper(II) complexes [Cu(5-nsal)(bipy)(ClO4)] (1) and [Cu(2-hnap)(bipy) (ClO4)] (2) (bipy = 2,2'-bipyridyl, 5-nsal = 5-nitrosalicylaldehyde and 2-hnap = 2-hydroxynaphthaldehyde) were successfully synthesized and physico-chemically characterized. The X-ray quality single crystals of copper(II) complexes showed that the copper atom was penta-coordinated with square- pyramidal geometry. The physicochemical characterizations of the copper(II) complexes also confirmed the formation of anticipated structures. The redox potentials of the complexes assessed by cyclic voltammetry showed a quasi-reversible redox behavior consistent with Cu(II)/Cu(I) reduction in the cathodic region.