Coligand driven efficiency of catecholase activity and proteins binding study of redox active copper complexes

Abstract

Two new copper complexes [Cu(HL)SCN] (1) and [Cu(HL)Cl(CH3OH)] (2) with tri-dentate Schiff-base ligand with alcoholic arm[H2L = 3-[(2-hydroxy-propylimino)-methyl]-naphthalen-2-ol] have been synthesized and characterized through several spectroscopic techniques and single crystal X-ray crystallography. The field strength of co-ligand has been found to be the key to dictate the geometry surrounding the metal ion. Where a moderate field strength of isothiocyanate ion stabilizes the complex in square-planar geometry, a weaker co-ligand like chloride induces a square-pyramidal geometry with one more additional ligand viz. methanol. Both the complexes have shown excellent catecholase like activity where compound 2 has been found to be more active through faster binding of substrate molecule through quicker dissociation of weaker co-ligands. In addition to their potential use as a bio-mimic catalyst in catechol oxidation, the interaction of these complexes with protein (BSA) was also studied to establish their potent role as metal-drug system.