Magnetostructural correlations and catecholase-like activities of mu-alkoxo-bridged dinuclear copper(II) complexes with 1-diethylaminopropan-2-ol, N-3(-), NCO- and NO2- ligands

Three new mu-alkoxo-bridged dinuclear copper(II) complexes with mu-1-diethylaminopropann-2-olate, [Cu-2{mu-Et2N-CH2CH(Me)O}(2)X-2] (X = N(3)(-)1,NCO(-)2 or NO(2)(-)3), have been prepared and characterized by single-crystal X-ray diffraction analyses. The copper atoms have distorted square-planar environments bridged by two oxygen atoms of alkoxo groups. Magnetic susceptibility measurements in the temperature range 5-300 K indicated significant antiferromagnetic coupling for 3 and ferromagnetic coupling for 1 and 2 between the copper(II) atoms. The best least-squares-fitted coupling constants (2J) for 1, 2 and 3 were 81, 25 and -42 cm(-1) respectively. By comparison to the known complex [Cu-2{mu-Et2NCH2CH(Me)O}(2)(NCS)(2)]4(2J = -86.0 cm(-1)), a linear correlation between the magnetic coupling constants and the mean Cu-O-Cu angle (phi) with a crossover point at phi 97.3 degrees from antiferromagnetic to ferromagnetic coupling is obtained. The catecholase activity of these copper(II) complexes for the oxidation of 3,5-di-tert-butylcatechol by O-2 was studied and shown to be in the Order 1 < 2 < 3.