Synthesis, crystal structure and magnetic properties of an oxamato-bridged heterobinuclear Ni^IICu^II complex [Ni(cyclam)Cu(opba)]₂·3DMSO

Abstract

An oxamato-bridged heterobinuclear Ni^IICu^II complex [Ni(cyclam)Cu(opba)]₂ · 3DMSO (1) has been synthesized, characterized by elemental analysis, infrared spectra and magnetic susceptibility, where cyclam is 1, 4, 8, 11-tetraazacyclotetradecane and opba is o-phenylenebis(oxamato). The complex crystallizes in the triclinic system, space group P 1 with a = 12.006(3) Å, b = 12.783(3) Å, c = 20.977(5) Å, α = 76.634(4)°, β = 75.172(4)°, γ = 80.818(4)° and Z = 2. According to X-ray crystallographic studies, the four-coordinate copper(II) atom is a slightly distorted planar geometry and is linked to nickel(II) through the exo-cis oxygen atoms of [Cu(opba)]²⁻; the six-coordinate nickel(II) center lies in a highly distorted octahedral environment. Magnetic susceptibility measurements of the complex in the temperature range 2–300 K indicate that the heterobinuclear Ni^IICu^II units are coupled antiferromagnetically with J = −57.38 cm⁻¹, g _Ni = 2.25 and g _Cu = 2.02.

Keywords:

• Macrocyclic complex
• Heterobinuclear
• Crystal structure
• Magnetism

Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (No. 20331020).