Antiferromagnetism in transition-metal complexes. Part I. Metal–metal bonding and spin exchange in binuclear copper(II) complexes

Abstract

The spin-exchange, pure d-orbital model of antiferromagnetic behaviour in binuclear copper(II) complexes is extended to include metal–metal bonding. A pattern of six thermally depopulated levels is obtained with one or two spin-singlets below a triplet depending upon whether the spin-coupling is direct or indirect via bridging groups. The model gives scope for improved fit of experimental results, and for gaining information on the strength of the metal–metal interaction and the origin of the predominant spin-coupling.