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

Four mononuclear imidazole adducts of copper(II) 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(II) 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)2(2mIm)2 (Val=valproate; 2mIm=2-methylimidazole) has been determined. The complex crystallizes in the P21/c space group with unit cell dimensions of a=9.309(1), b=12.456(2), c=12.560(2) Å, β=99.84(1)°, V=1435.0(3) Å3, Z=2.