TY - JOUR A1 - Jay, Raphael M. A1 - Norell, Jesper A1 - Eckert, Sebastian A1 - Hantschmann, Markus A1 - Beye, Martin A1 - Kennedy, Brian A1 - Quevedo, Wilson A1 - Schlotter, William F. A1 - Dakovski, Georgi L. A1 - Minitti, Michael P. A1 - Hoffmann, Matthias C. A1 - Mitra, Ankush A1 - Moeller, Stefan P. A1 - Nordlund, Dennis A1 - Zhang, Wenkai A1 - Liang, Huiyang W. A1 - Kunnus, Kristian A1 - Kubicek, Katharina A1 - Techert, Simone A. A1 - Lundberg, Marcus A1 - Wernet, Philippe A1 - Gaffney, Kelly A1 - Odelius, Michael A1 - Föhlisch, Alexander T1 - Disentangling Transient Charge Density and Metal-Ligand Covalency in Photoexcited Ferricyanide with Femtosecond Resonant Inelastic Soft X-ray Scattering JF - The journal of physical chemistry letters N2 - Soft X-ray spectroscopies are ideal probes of the local valence electronic structure of photocatalytically active metal sites. Here, we apply the selectivity of time resolved resonant inelastic X-ray scattering at the iron L-edge to the transient charge distribution of an optically excited charge-transfer state in aqueous ferricyanide. Through comparison to steady-state spectra and quantum chemical calculations, the coupled effects of valence-shell closing and ligand-hole creation are experimentally and theoretically disentangled and described in terms of orbital occupancy, metal-ligand covalency, and ligand field splitting, thereby extending established steady-state concepts to the excited-state domain. pi-Back-donation is found to be mainly determined by the metal site occupation, whereas the ligand hole instead influences sigma-donation. Our results demonstrate how ultrafast resonant inelastic X-ray scattering can help characterize local charge distributions around catalytic metal centers in short-lived charge-transfer excited states, as a step toward future rationalization and tailoring of photocatalytic capabilities of transition-metal complexes. Y1 - 2018 U6 - https://doi.org/10.1021/acs.jpclett.8b01429 SN - 1948-7185 VL - 9 IS - 12 SP - 3538 EP - 3543 PB - American Chemical Society CY - Washington ER -