Chemical Trends in the Near-Edge X-ray Absorption Fine Structure of Monosubstituted and Para-Bisubstituted Benzenes
| Autor: | Stephen G. Urquhart, Ryan R. Cooney and |
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| Rok vydání: | 2004 |
| Předmět: |
Chemistry
Chemical shift Analytical chemistry Molecular physics XANES Spectral line Surfaces Coatings and Films X-ray absorption fine structure Atomic electron transition Ab initio quantum chemistry methods Materials Chemistry Molecule Physical and Theoretical Chemistry Absorption (electromagnetic radiation) |
| Zdroj: | The Journal of Physical Chemistry B. 108:18185-18191 |
| ISSN: | 1520-5207 1520-6106 |
| DOI: | 10.1021/jp046868j |
| Popis: | Carbon 1s (C−R) → π*CC electronic transitions originating from the substituent-bonded carbon atom of a benzene ring show distinctive chemical shifts in their near-edge X-ray absorption fine structure (NEXAFS) spectra. We have systematically explored these chemical shifts through ab initio calculations and carefully calibrated experimental data for a wide range of molecules containing substituted benzene rings. The systematic disparity between experimental and calculated transition energies was used to develop a semiempirical correction for this class of transitions, allowing us to map calculated transition energies onto a corrected, experimental energy scale. The correction method was applied to a large set of calculated core C 1s (C−R) → π*CC transition energies, and used to prepare a chemically wide-ranging NEXAFS correlation diagram for the “C−R π* band”. We demonstrate the usefulness of this correlation diagram for the analytical application of NEXAFS spectroscopy and microscopy to organic materials. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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