Four Copper(II) Diclofenac Complexes with Pyridine Derivatives: Synthesis, Crystal Structures, Spectroscopic Properties, Thermal Analysis and Catechol Oxidase Activities

Abstract

Four novel mononuclear copper(II) complexes [Cu(dicl)<inf>2</inf>(2-pic) <inf>2</inf>] 1, [Cu(dicl)<inf>2</inf>(3-pic)<inf>2</inf>] 2, [Cu(dicl) <inf>2</inf>(4-pic)<inf>2</inf>] 3 and [Cu(dicl)<inf>2</inf>(2-ampy) <inf>2</inf>] 4 have been synthesized. The crystal structures of the complexes 2 and 3 have been determined by X-ray crystallography. X-ray structure analysis has shown that copper(II) ions have distorted octahedral geometry in 2 and 3 and diclofenac coordinates to Cu(II) ion as a deprotonated ligand through carboxylato oxygens. Four complexes have been characterized by elemental analysis and IR spectroscopy. Their thermal stabilities have been determined by TG/DTA/DTG techniques. Four mononuclear complexes have shown catalytic activity on the oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone exhibiting saturation kinetics at high substrate concentrations. © 2013 Elsevier B.V. All rights reserved.