Moment Analysis of Magnetic Circular Dichroism: Diamagnetic Molecular Solutions

Abstract

The method of moments enables more rigorous analysis of magnetic circular dichroism data than rigid shift models. Moment analysis is here applied to magnetic circular dichroism measurements on room temperature solutions of MnO₄⁻, CrO₄²⁻, PdCl₄²⁻, SbCl₆⁻, Ni(CN)₄²⁻, Fe(CN)₆⁴⁻, triphenylene, and coronene. Qualitative conclusions previously reached on the basis of rigid shift models are shown to be very little affected. More accurate values for the magnetic moments of degenerate excited state manifolds are obtained. The new data for Fe(CN)₆⁴⁻ support the assignment of the 47 000 cm⁻¹ absorption band to an intramolecular, $t_{\text{2g}}{\mathrm{\hspace{0.17em}\to \hspace{0.17em}t}}_{\text{1u}}$ metal‐to‐ligand transition.