Ligand Ordering Parameters

Abstract

Lanthanide and actinide single-ligand crystal field parameters are shown to define similar spectrochemical series to the cubic parameter for 3d ions, providing direct evidence that the dominant electronic processes which cause crystal field splittings are the same for all open-shell ions. The contrast between the nephelauxetic series and the spectrochemical series and the existence of a strong empirical correlation between the former and ligand polarizability show that the nephelauxetic series cannot be determined by the admixture of ligand and open-shell wavefunctions as is often assumed. The influence of ligand polarizability on various spectroscopic parameters is then discussed.