Metal-to-ligand charge transfer in polarized metal L-edge X-ray absorption of Ni and Cu complexes

Metal L-edge X-ray absorption spectra for Ni and Cu complexes are discussed by investigating their linear polarization dependence. The origin of the characteristic bands is revealed to be one-electron transitions to ligand-centered molecular orbitals carrying metal-to-ligand charge transfer (MLCT). These MLCT transitions are related to the electronic structure of the ground state, particularly, the back-donation. Polarized L-edge X-ray absorption spectroscopy is applied to reveal electronic structures of metal complexes with doped hole and nickel-nickel bonding. (C) 2004 Elsevier B.V. All rights reserved.