Optical activity of coordination compounds. ii. a molecular orbital model and an analysis of experimental data for complexes of trigonal symmetry

Abstract

A molecular orbital model for the optical activity of trigonal coordination compounds is developed. It is shown that the combination of intensity data from solution and crystal spectra with optical activity data from solution allows one to calculate empirical values of the electric moment matrix elements for the one-electron transition t2→e. This empirical electric moment matrix is in good agreement with that predicted by the molecular-orbital model, and it is in nearly as good agreement with that of the ionic model as far as the ratios of the matrix elements are concerned. Empirical values of the magnetic moment of the electronic transitions are interpreted qualitatively in terms of metal-ligand covalency. The problem of determining the absolute configuration from the sign of the rotational strength is discussed.