A model for the interpretation of the absorption and circular dichroism spectra of tris(di-imine) complexes of iron(II) and ruthenium(II)

Abstract

A theoretical model of the electronic structure of the metal-to-ligand charge-transfer (m.l.c.t.), ligand-centred (l.c.) and metal-centred (m.c.) states of tris(di-imine)metal(II), [ML₃]²⁺(M = Fe or Ru), is developed. The model contains only three adjustable parameters describing the first-order mixing of metal and ligand wavefunctions. All the state matrix elements are simplified by tensor operator techniques to reduced one-electron matrix elements, which are calculated numerically using Slater type orbitals. A quantitative prediction of the absorption and circular dichroism spectra, including all spin-allowed m.l.c.t., l.c., and m.c. bands of [ML₃]²⁺ is made, using a reasonable set of mixing parameters, which is in good agreement with the experimental results.