Studies on the Valence State of Iron Atoms in the Mixed-Valence Binuclear Ferrocenes by X-Ray Absorption Near Edge Structure (XANES) and by X-Ray Photoelectron Spectroscopy (XPS)

Abstract
In order to study the valence state in the mixed-valence binuclear ferrocenes, X-ray absorption spectra near the Fe K-edge were measured using synchrotron radiation. Well-resolved lines in the spectra obtained for ferrocene derivatives were assigned to the 1s→3d, 1s→Cp(π*), and 1s→4p transitions, respectively, based on the molecular orbitals. There is an apparent difference in the 1s→3d transitions between trapped-valence compounds and averaged-valence compounds in the I3 salts of the monocation of binuclear ferrocenes. The valence states of the mixed-valence binuclear ferrocenes were also studied by X-ray photoelectron spectroscopy.