Antiferromagnetism in transition-metal complexes. Part V. Binuclear copper(II) complexes with bridging aromatic N-oxide groups

Abstract

Variable-temperature magnetic susceptibility data for a number of 1:1 aromatic N-oxide complexes of cupric halides are reinterpreted on a model which allows for the thermal population of excited states other than those predicted by the vector-coupling model. The mechanism of superexchange through the oxygen bridges is discussed and is found to be dominated by two paths which promote an effective metal–metal overlap in opposite senses, yet co-operate in the antiferromagnetic exchange process. Analogous data on the 2 : 1 series is more limited but the relationship between structure and magnetic properties is reaffirmed for these more diverse compounds.