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 CuSO 4 ·5H 2 O or Cu(CH 3 COO) 2 ·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 ¯ , while 2 crystallizes in the monoclinic crystal system with the space group P 2 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.