MPI für bioanorganische Chemie / MPI für bioanorganische Chemie |
|Valence-to-Core-Detected X-ray Absorption Spectroscopy: Targeting Ligand Selectivity|
|Authors:||Hall, Eleanor R.; Pollock, Christopher J.; Bendix, Jesper; Collins, Terrence J.; Glatzel, Pieter; DeBeer, Serena|
|Date of Publication (YYYY-MM-DD):||2014|
|Title of Journal:||Journal of the American Chemical Society|
|Journal Abbrev.:||J. Am. Chem. Soc.|
|Issue / Number:||28|
|Abstract / Description:||X-ray absorption spectroscopy (XAS) can provide detailed insight into the electronic and geometric structures of transition-metal active sites in metalloproteins and chemical catalysts. However, standard XAS spectra inherently represent an average contribution from the entire coordination environment with limited ligand selectivity. To address this limitation, we have investigated the enhancement of XAS features using valence-to-core (VtC)-detected XAS, whereby XAS spectra are measured by monitoring fluorescence from valence-to-core X-ray emission (VtC XES) events. VtC emission corresponds to transitions from filled ligand orbitals to the metal Is core hole, with distinct energetic shifts for ligands of differing ionization potentials. VtC-detected XAS data were obtained from multiple valence emission features for a series of well-characterized Mn model compounds; taken together, these data correspond to a VtC resonant XES (VtC RXES) plane. For comparison, standard total fluorescence yield (TFY) XAS and nonresonant XES data were obtained. Dramatic intensity variations and the appearance of new features were observed in the pre-edge region by detecting at different VtC emission energies. The TFY XAS, nonresonant XES, and VtC RXES data were all modeled within a density functional theory approach. While the TFY XAS and nonresonant XES data are readily interpreted by theory, the VtC RXES cannot be reproduced within such a simplified model. Nonetheless, dramatic changes in the experimental spectra are observed that have the potential to further the information content and selectivity of XAS. Potential applications and required theoretical developments are discussed.|
|External Publication Status:||published|
|Communicated by:||N. N.|
|Affiliations:||MPI für bioanorganische Chemie|
|External Affiliations:||[Hall,E.R.]Univ Oxford, Dept Chem, Oxford OX1 2JD, England.
[Bendix,J.]Univ Copenhagen, Dept Chem, DK-2100 Copenhagen, Denmark.
[Collins,T.J.]Carnegie Mellon Univ, Dept Chem, Pittsburgh, PA 15213 USA.
[Glatzel,P.]European Synchrotron Radiat Facil, F-38000 Grenoble, France.
|Identifiers:||ISI:000339228200048 [ID No:1] |
ISSN:0002-7863 [ID No:2]
DOI:10.1021/ja504206y [ID No:3]
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