Synthesis and Characterization of Imidazolate-Bridged Binuclear Copper(II) Complexes

An unsymmetrical quadridentate copper(II) complex containing an imidazole moiety ([CuHL](ClO4)) reacts with [1,4,7,10-tetraazacyclododecane]copper(II) perchlorate and [2-[2-(2-pyridyl)ethyliminomethyl]pyridine]copper(II) perchlorate in the presence of one equivalent of triethylamine to give two discrete imidazolate-bridged binuclear copper(II) complexes, 1 and 2 respectively, where [H2L] denotes the 1:1:1 condensation product of acetylacetone, ethylenediamine, and 4-formylimidazole. The analysis of the cryomagnetic data(ca. 80–300 K) on the basis of the Heisenberg model of a binuclear structure gave the antiferromagnetic interaction parameter(2J) of −107.7 cm−1 for 2.