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MO: Fachverband Molekülphysik
MO 21: Electronic Spectroscopy I
MO 21.2: Vortrag
Donnerstag, 17. März 2011, 10:45–11:00, MER 02
Charge Transfer between Co(II) and H20 vs D2O quantified by Dark Channel Fluorescence Yield XAS. — Samira Ghadimi1, Sebastien Bonhommeau2, •Mikhail Soldatov1,3, Kathrin M Lange1, Tom Stalinski1, Alexander Kothe1, Kai F Hodeck1, Alexander Soldatov3, and Emad F Aziz1,4 — 1Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany — 2Institut des Sciences, Moléculaires, Université Bordeaux 1, Talence Cedex, France — 3Southern Federal University, Research Center for Nanoscale Structure of Matter, Rostov-on-Don, Russia — 4Freie Universität Berlin, FB Physik, Berlin, Germany
The electronic structure of Co(II) ions in water vs D2O solution was characterized by soft X-ray absorption spectroscopy. The X-ray absorption of the Co(II) L2,3-edges was obtained experimentally in both, transmission and fluorescence mode. The spectra measured in fluorescence mode show significant deviations in shape and intensity of the L3 and L2 edge features as compared to the transmission spectra. This can be explained by the dark-channel fluorescence yield (DCFY) mechanism found recently by us [1,2]. Ligand-field multiplet simulations of the spectra were performed, to model the charge transfer of the Co(II) ions in the different solvents, and analyzed in terms of the Co-O-H2 bonding strength. The intensity of the L2,3-edges fluorescence from the Co(II) ions was reduced due to the DCFY mechanism but shows no sub background dip as it was observed for Fe(III) ions in water [1,2].
[1] Emad F. Aziz et.al., Nature Chemistry 2010, 768, 853-857
[2] News and Views Nature Chemistry 2 2010, 800-802