title: Measuring Spin-Allowed and Spin-Forbidden d-d Excitations in Vanadium Complexes with 2p3d Resonant Inelastic X-ray Scattering.
abstract: Spectroscopic probes of the electronic structure of transition metal-containing materials are invaluable to the design of new molecular catalysts and magnetic systems. Herein, we show that 2p3d resonant inelastic X-ray scattering (RIXS) can be used to observe both spin-allowed and (in the VIIIcase) spin-forbidden d-d excitation energies in molecular vanadium complexes. The spin-allowed d-d excitation energies determined by 2p3d RIXS are in good agreement with available optical data. In V(acac)3, a previously undetected spin-forbidden singlet state has been observed. The presence of this feature provides a ligand-field independent signature of VIII. It is also shown that d-d excitations may be obtained for porphyrin complexes. This is generally prohibitive using optical approaches due to intense porphyrin π-to-π* transitions. In addition, the intensities of charge-transfer features in 2p3d RIXS spectroscopy are shown to be a clear indication of metal-ligand covalency. The utility of 2p3d RIXS for future studies of complex inorganic systems is highlighted.
authors.affiliation: Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Benjamin E
authors.initials: BE
authors.lastname: Van Kuiken
authors.affiliation: Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Anselm W
authors.initials: AW
authors.lastname: Hahn
authors.affiliation: Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Maganas
authors.affiliation: Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.|Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.
authors.forename: Serena
authors.initials: S
authors.lastname: DeBeer