Highly Accurate Excited-State Structure of [Os(bpy)(2)dcbpy](2+) Determined by X-ray Transient Absorption Spectroscopy
Author
Summary, in English
Determining the electronic and geometric structures of photoexcited transient species with high accuracy is crucial for understanding their fundamental photochemistry and controlling their photoreactivity. We have applied X-ray transient absorption spectroscopy to measure the XANES and EXAFS spectra of a dilute (submillimolar) solution of the osmium(II) polypyridyl complex [Os(bpy)(2)dcbpy](PF6)(2) (dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) (OsL2L') in methanol at the Os L-III edge. We have obtained spectra of superb quality for both the ground state and the photoinduced (MLCT)-M-3 excited state that have allowed us not only to extract detailed information about the Os 5d orbitals but also to resolve very small differences of 0.010 +/- 0.008 angstrom in the average Os-N bond lengths of the ground and excited states. Theoretical calculations using a recently developed DFT-based approach support the measured electronic structures and further identify the nature of the molecular orbitals that contribute to the main absorption bands in the XANES spectra.
Publishing year
2014
Language
English
Pages
8804-8809
Publication/Series
Journal of the American Chemical Society
Volume
136
Issue
24
Document type
Journal article
Publisher
The American Chemical Society (ACS)
Topic
- Atom and Molecular Physics and Optics
Status
Published
ISBN/ISSN/Other
- ISSN: 1520-5126