Di-, Tetra-, and Polynuclear Copper(II) Complexes: Active Catalysts for Oxidation of Toluene and Benzene

Three copper(II) complexes with a binucleating N2O donor ligand, [Cu-2(L-1)(mu(2)-pz)(CH3COO)(2)] (1), [Cu-4(L-1)(2)(mu(4)-O)(mu(2)-CH3COO)(2)(mu(1,1)-N-3)(N-3)] (2), and [Cu-2(L-2) (mu(1,1)-N-3)(mu(1,3)-N-3)(2)](infinity) (3) [pz = pyrazolato, HL1 = 2,6-bis(morpholinomethyl)-4-tert-butylphenol and HL2 = 2,6-bis(morpholinomethyl)-4-methylphenol] have been synthesized and characterized by elemental analysis, FTIR and UV/Vis spectroscopy, and X-ray crystallography. X-ray crystallographic studies revealed that a series of di-, tetra-, and polynuclear complexes have been formed by varying the bridging ligand, counteranion, and reaction conditions. These show effective catalytic properties for the hydrogen peroxide oxidation of toluene and benzene. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)