Characterization and catecholase-mimetic behavior of imidazole adducts of copper(II) valproate. Crystal structure of the 2-methylimidazole adduct

Abstract

Four mononuclear imidazole adducts of copper(I1) valproate have been prepared and characterized with IR, UV-Vis, EPR spectroscopic techniques and fast atom bombardment mass spectrometry. The catecholase-mimetic catalytic activities of the complexes have been determined by monitoring the formation of o-quinone from catechol. The catalytic activities of the mononuclear complexes are lower than that of the dinuclear copper(H) valproate. The complexes with 2-methylimidazole and 1,2-dimethylimidazole show slightly lower activities that the imidazole and N-methylimidazole complexes. The structure of Cu(Val)z(2mIm), (Val =valproate; 2mIm = 2-methylimidazole) has been determined. The complex crystallizes in the p2,/c space group with unit cell dimensions of a =9.309(l), b = 12.456(2), c = 12.560(2) A, p = 99.84(l)“, I/= 1435.0(3) b;‘, Z = 2.