Electronic and molecular structure of photoexcited [Ru-II(bpy)(3)](2+) probed by picosecond X-ray absorption spectroscopy

Publication date

2006-04-19

Authors

Gawelda, W
Johnson, M
de Groot, FrankISNI 0000000114483312
Abela, R
Bressler, C
Chergui, M

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Document Type

Article
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Abstract

L-2,L-3 X-ray absorption spectra of aqueous [Ru-II(bpy)(3)](2+) have been recorded in its ground and excited states, 50 ps after short pulse laser excitation. Significant changes in both the XANES (X-ray Near-Edge Absorption Structure) and the EXAFS (Extended X-ray Absorption Fine Structure) regions of the excited state complex are detected. The XANES line shapes have been quantitatively simulated using a crystal field multiplet code in trigonal symmetry. In addition, spectral changes in the EXAFS region of both ground and excited states are analyzed in order to extract structural parameters of their corresponding molecular structures. We obtain a Ru-N bond contraction by similar to 0.03 angstrom in the excited-state complex, as compared to the ground-state compound. This contraction results from electrostatic and polarization contributions, limited by steric constraints on the bpy ligands.

Keywords

TRANSITION-METAL-COMPLEXES, NEAR-EDGE STRUCTURE, QUANTUM-CHEMICAL CALCULATIONS, LIGAND CHARGE-TRANSFER, EXCITED-STATES, POLYPYRIDINE COMPLEXES, COORDINATION-COMPOUNDS, CRYSTAL-STRUCTURES, SPECTRA, PHOTOCHEMISTRY, Taverne

Citation

Gawelda, W, Johnson, M, de Groot, FMF, Abela, R, Bressler, C & Chergui, M 2006, 'Electronic and molecular structure of photoexcited [Ru-II(bpy)(3)](2+) probed by picosecond X-ray absorption spectroscopy', Journal of the American Chemical Society, vol. 128, no. 15, pp. 5001-5009. https://doi.org/10.1021/ja054932k