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)2(2-pic)2] 1, [Cu(dicl)2(3-pic)2] 2, [Cu(dicl)2(4-pic)2] 3 and [Cu(dicl)2(2-ampy)2] 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.