Synthesis, crystal structure, spectroscopic, thermal, catechol oxidase and catalase-like studies: New copper(II) complexes of 2-benzoylbenzoate and 2-pyridilpropanol ligands

Abstract

Two novel copper(II) complexes, mononuclear [Cu(bba)(2)(pypr)(2)] 1 and dinuclear [Cu-2(bba)(2)(pypr)(2)] 2, have been synthesized by reactions of 2-pyridilpropanol with CuSO4 center dot 5H(2)O or Cu(CH3COO)(2)center dot 2H(2)O metal salt in the presence of 2-benzoylbenzoic acid. The copper(II) ion has a distorted octahedral geometry in 1 and distorted square pyramidal geometry in 2. 1 crystallizes in space group P (1) over bar, while 2 crystallizes in the monoclinic crystal system with the space group P2(1)/n. 2-Benzoylbenzoate behaves as a monodentate in 1, bidentate in 2. 2-pyridilpropanol ligand acts as a bidentate in 1 and bridging in 2. Both complexes were characterized by elemental analysis, mass and IR spectroscopy. Their molecular structures were determined by X-ray crystal structure analysis and their thermal stabilities were confirmed by TG/DTA/DTG techniques. Dinuclear compound shows high catalytic activity regarding the oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone exhibiting saturation kinetics at high substrate concentrations. In addition, dinuclear compound demonstrates significantly catalase-like activity. But mononuclear complex shows neither catalase-like nor catechol oxidase activity. (C) 2012 Elsevier B. V. All rights reserved.