1. Excited state charge distribution and bond expansion of ferrous complexes observed with femtosecond valence-to-core x-ray emission spectroscopy
- Author
-
Dimosthenis Sokaras, Roberto Alonso-Mori, Diana B. Zederkof, Alessandro Gallo, Amy A. Cordones, Kelly J. Gaffney, Silke Nelson, Elisa Biasin, Kristjan Kunnus, Alexander Britz, Kathryn Ledbetter, Marco Reinhard, Kristoffer Haldrup, James M. Glownia, Clemens Weninger, and Tim Brandt van Driel
- Subjects
Materials science ,Valence (chemistry) ,010304 chemical physics ,General Physics and Astronomy ,Charge density ,010402 general chemistry ,01 natural sciences ,Molecular physics ,0104 chemical sciences ,Bond length ,Excited state ,0103 physical sciences ,Density functional theory ,Emission spectrum ,Physical and Theoretical Chemistry ,Spectroscopy ,Ground state - Abstract
Valence-to-core x-ray emission spectroscopy (VtC XES) combines the sample flexibility and element specificity of hard x-rays with the chemical environment sensitivity of valence spectroscopy. We extend this technique to study geometric and electronic structural changes induced by photoexcitation in the femtosecond time domain via laser-pump, x-ray probe experiments using an x-ray free electron laser. The results of time-resolved VtC XES on a series of ferrous complexes [Fe(CN)2n(2, 2′-bipyridine)3−n]−2n+2, n = 1, 2, 3, are presented. Comparisons of spectra obtained from ground state density functional theory calculations reveal signatures of excited state bond length and oxidation state changes. An oxidation state change associated with a metal-to-ligand charge transfer state with a lifetime of less than 100 fs is observed, as well as bond length changes associated with metal-centered excited states with lifetimes of 13 ps and 250 ps.
- Published
- 2020
- Full Text
- View/download PDF