Neutron inelastic scattering study of exchange interactions in a chromium(III) dimer: μ-hydroxo-bis[pentaamminechromium-(III)] chloride monohydrate

Abstract

Neutron inelastic scattering is introduced as a new experimental technique for the study of exchange interactions in polynuclear transition metal complexes. Measurements were performed on deuterated μ-hydroxo-bis[pentaamminechromium(III)]chloride monohydrate at temperatures ranging from 5 K to 290 K. Transitions between split levels of the electronic ground state were observed in both energy-gain and energy-loss configurations. The values for the splittings and the resulting exchange parameters are found to be temperature dependent. Comparisons are made with values obtained from optical spectroscopic studies and magnetic susceptibility measurements. The observed intensity ratios of the neutron inelastic scattering transitions are in good agreement with values calculated on the basis of a simple spin-spin coupling model for the chromium pair.