Copper complexes of 1-[(2-carboxyethyl)benzene]-3-[2-pyridine]triazene

The triazenide, 1-[(2-carboxyethyl)benzene]-3-[2-pyridine]triazene (HL), has been synthesized. In the presence of Et3N, the reaction of HL with Cu(OAc)2·H2O or CuCl2·2H2O gives the tetranuclear copper(II) complexes {Cu4(L)2(μ2-OH)2(OAc)4} 1 and {Cu4L4(μ4-O)Cl2} 2, respectively. The X-ray crystal structures of both complexes have been obtained. Magnetic studies indicate significant antiferromagnetic coupling between the copper(II) centers for both complexes, with coupling constants (J) of −493.4 cm−1 for 1 and −165 cm−1 for 2.