Systematics of metal-ligand binding energies

Abstract

An important aspect in the thermochemistry of coordination complexes is the binding energies of ligands to metals. Although bond-energy schemes are successful for alkanes and substituted alkanes they are not easily applied to coordination compounds. Dissociation energies are not a direct measure of binding energies because of the reorganization energies of the radicals. A more profitable approach is to consider the dissociation energy of the complex relative to that of the ligand with hydrogen. In normal circumstances, DH(M-L) -DH(H-L) for a particular metal and type of ligand appears to be constant. This leads to simple relations between enthalpies of formation of complexes and their corresponding ligands which are useful for evaluating existing data and for predicting unknown enthalpies of formation. © 1989 IUPAC