N,N,N-三齿席夫碱铜(Ⅱ)配合物的合成、晶体结构及儿茶酚酶活性OA北大核心CSTPCD

Four complexes,[Cu(L1)Cl2](1),[Cu(L1)(SCN)2](2),[Cu(L1)bpy](ClO4)2·CH3OH(3)and[Cu(L2)bpy](ClO4)2(4),were synthesized via the reaction of the N,N,N-tridentate Schiff base ligands,2-[(1H-benzimidazol-2-yl-ethylimino)-methyl]pyridine(L1)or 2-[(1H-benzimidazol-2-yl-propylimino)-methyl]pyridine(L2)with Cu(Ⅱ)salts(where bpy=2,2′-bipyridine).The complexes were characterized by means of elemental analysis,infrared spectroscopy,powder X-ray diffraction,single-crystal X-ray diffraction,thermal gravimetric analysis and cyclic voltammetry.In the solid state,complexes 1～4 are mononuclear Cu(Ⅱ)complexes and the Cu(Ⅱ)ions exhibit distorted square pyramidal coordination geometry with τ values ranging from 0.088 to 0.340.Catecholase activity of the complexes has been studied using 3,5-di-tertbutyl catechol(3,5-DTBC)as model substrate,and kinetic parameters were calculated using the Michaelis-Menten model and Lineweaver-Burk plot.The results demonstrate that all complexes exhibit catecholase activity,with the catechol oxidation rates following the order of 2>3≈4>1.The oxidation rates depend on the distortion of the Cu(Ⅱ)coordination environment,the bond lengths of the leaving group of Cu(Ⅱ)ions and the steric hindrance of the complexes.