Mixed Valency in Inorganic Chemistry

Abstract

The aim of these lectures is to survey the occurrence of mixed oxidation states in inorganic compounds throughout the Periodic Table and to show how chemists have sought to relate structures to physical properties. We shall focus on the extent of electron delocalization between ion sites, and the extent to which it is determined by ligand field differences and the nature of the ligands bridging the metal ion sites. The older static model of Robin and Day will be put into the context of the more recent vibronic model of Piepho, Kransz and Schatz. Model examples will be taken from discrete dimeric molecules, and extended to clusters and infinite lattices, especially chains.