Probing valence orbital composition with iron Kbeta X-ray emission spectroscopy
Nicole Lee1, Taras Petrenko, Uwe Bergmann
1Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
Journal of the American Chemical Society
|June 29, 2010
Summary
This study analyzes iron Kbeta X-ray emission spectra (XES) to understand chemical environments. The valence region of XES is sensitive to spin state and ligand changes, aiding catalysis research.
Area of Science:
- Solid-state chemistry and spectroscopy
- Computational chemistry and materials science
Background:
- X-ray emission spectroscopy (XES) is a powerful tool for probing electronic structure.
- Iron Kbeta XES provides insights into the oxidation and spin states of iron compounds.
Purpose of the Study:
- To systematically investigate ferric and ferrous Kbeta X-ray emission spectra (XES).
- To evaluate factors influencing the Kbeta main line and valence-to-core regions.
- To establish a calibration for analyzing iron active sites in catalysis.
Main Methods:
- Experimental measurement of 12 ferric and ferrous Kbeta XES.
- Quantitative assessment of spectral contributions.
- Density functional theory (DFT) calculations for spectral simulation and analysis.
Main Results:
- Kbeta main line spectra are primarily influenced by spin state.
- The valence-to-core region exhibits high sensitivity to chemical environment changes (ligand identity, ionization state, hybridization, bond lengths).
- Iron np to 1s electric dipole transitions dominate the spectra.
Conclusions:
- Kbeta XES is a sensitive probe of iron's electronic and chemical environment.
- DFT calculations accurately reproduce experimental valence spectra.
- These findings provide crucial calibration for applying XES to catalytic iron sites, including Compound II heme derivatives.
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