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

Three copper(II) complexes with a binucleating N 2O donor ligand, [Cu 2(L 1)(μ 2-pz)(CH 3COO) 2] (1), [Cu 4(L 1) 2(μ 4- O)(μ 2-CH 3COO) 2(μ 1,1-N 3)(N 3)] (2), and [Cu 2(L 2) (μ 1,1-N 3)(μ 1,3-N 3) 2] ∞ (3) [pz = pyrazolato, HL 1 = 2,6-bis(morpholinomethyl)-4-tert-butylphenol and HL 2 = 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.