Theories of Coordination Compounds

Werner treated bonding in coordination compounds as a Lewis acid-Lewis base interaction, which explains many observed properties but not colour or magnetism. Following Werner, Linus Pauling proposed Valence Bond Theory (VBT), assuming a purely covalent metal-ligand bond; Bethe and Van Vleck instead treated the metal-ligand interaction as purely electrostatic and extended Crystal Field Theory (CFT) from ionic crystals to coordination compounds. Ligand field theory and molecular orbital the …