Some relationships among the stabilities of metal complexes

Abstract

AbstractThe stability constant, KML, of the first metal‐ligand complex, ML, can be related to the stability constant, KHL, of the corresponding proton‐ligand complex, and to the partial molar free energies of the various species in solution. The relationship has been modified for application to mixtures of aqueous and organic solvents. For closely related ligands, log KML, will be an approximately linear function of log KHL. Moreover, log KML, is often a linear function of the molar fraction of the organic component of the mixed solvent.The relationships between the stabilities of very closely related complexes are also discussed, and illustrated with reference to metal complexes of some derivatives of oxine, and to other metal chelates. Steric hindrance to complex formation may cause large deviations from predicted behaviour.