Page "Charge-transfer complex" Paragraph 3

In inorganic chemistry, most charge-transfer complexes involve electron transfer between metal atoms and ligands.

The charge-transfer bands in transition metal complexes result from shift of charge density between molecular orbitals ( MO ) that are predominantly metal in character and those that are predominantly ligand in character.

If the transfer occurs from the MO with ligand-like character to the metal-like one, the complex is called a ligand-to-metal charge-transfer ( LMCT ) complex.

If the electronic charge shifts from the MO with metal-like character to the ligand-like one, the complex is called a metal-to-ligand charge-transfer ( MLCT ) complex.

Thus, a MLCT results in oxidation of the metal center, whereas a LMCT results in the reduction of the metal center.

Resonance Raman Spectroscopy is also a powerful technique to assign and characterize charge-transfer bands in these complexes.