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)].

Keywords:

• Spin‐exchange
• Heterotrinuclear complexes
• Charge transfer
• ESR
• Cu(Meoxpn)

Acknowledgments

This project was supported by the National Natural Science Foundation of China and the Natural Science Foundation of Shandong Province.