Synthesis and Magnetism of {[Cu(II)]2Ln(III)} Heterotrinuclear Complexes Bridged by N,N'‐bis(3‐Amino‐2‐methylpropyl)oxamidocopper(II)

Abstract

Ten new μ‐oxamido‐bridged {[Cu(II)]2Ln(III)}‐type heterotrinuclear complexes described by the overall formula Cu2(Meoxpn)2Ln(NO3)3 (Ln = Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er), where Meoxpn denotes the N,N′‐bis(3‐amino‐2‐methylpropyl)oxamido dianion, have been synthesized and characterized by elemental analyses, molar conductivity measurements, and spectroscopic (IR, UV, and ESR) characterization. Magnetic susceptibility (4.2–300 K) studies of the Cu2(Meoxpn)2–Gd(NO3)3 complex have revealed that the central gadolinium(III) and terminal copper(II) ions are ferromagnetically coupled with the exchange integral J (Cu–Gd) = +3.85 cm−1, while an antiferromagnetic coupling is detected between the two terminal copper(II) ions with the exchange integral J′(Cu–Cu) = −0.98 cm−1, on the basis of the spin Hamiltonian operator [ Ĥ = −2J (Ŝ Cu1 Ŝ Gd + Ŝ Cu2 Ŝ Gd) − 2J′(Ŝ Cu1 Ŝ Cu2)].