Synthesis and Magnetism of Novel μ-Oxamido Heterobinuclear Copper (II)-Lanthanide (III) Complexes

Abstract

Six novel μ-oxamido heterobinuclear complexes, namely Cu(oxap) Ln(Me₂bpy)₂(CIO₄)₃ (Ln = La, Nd, Gd, Tb, Ho, Er), where oxap denotes N, N′-bis(2-aminopropyl)oxamido dianion, Me₂bpy is 4, 4′-dimethyl-2, 2′-bipyridine, have been synthesized and characterized by elemental analyses, IR, conductivity measurements and electronic spectra. The temperature dependence of the magnetic susceptibility of Cu(oxap) Gd(Me₂ bpy)₂ (CIO₄)₃ has been measured over the range 4 ∼ 300 K. The least-squares fit of the experimental susceptibilities yielded J = 7.90 cm⁻¹. The observed Gd(III)-Cu(II) coupling is ferromagnetic. A plausible mechanism that can cause a ferromagnetic coupling between Gd (III) and Cu(II) is discussed in terms of spin-polarization.