Synthesis and magnetic properties of binuclear copper(II) complexes with N,N′-bis(2-aminoethyl)oxamidocopper(II)

Abstract

Four binuclear complexes have been synthesized, namely [Cu(oxae)CuL](ClO 4) 2, where oxae denotes the N,N′-bis(2-aminoethyl)oxamido dianion and L denotes 2,2′-bipyridyl (bpy), 4,4′-dimethyl-2,2′-bipyridyl (Me 2bpy), 1,10-phenanthroline (phen) or 5-nitro-1,10-phenanthroline (NO 2-phen). Based on IR, elemental analyses, conductivity measurements and electronic spectra, these complexes are proposed to have extended oxamido-bridged structures and to consist of the two copper(II) ions in a planar environment. The temperature dependence of the magnetic susceptibilities of [Cu(oxae)Cu(NO 2-phen)](ClO 4) 2 has been studied in the range 4.2–300 K, giving the exchange integral J = −243.5 cm −1, indicating that a strong antiferromagnetic spin-exchange interaction operates between metal ions.