Source:http://linkedlifedata.com/resource/pubmed/id/17489631
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| Predicate | Object |
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| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
21
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| pubmed:dateCreated |
2007-5-24
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| pubmed:abstractText |
Ruthenium-polypyridine and related complexes play an important role as models for light-harvesting antenna systems to be employed in artificial photosynthesis. In this theoretical and experimental work, the first photoexcitation step of a tetranuclear [Ru2Pd2] complex composed of two ruthenium-bipyridyl subunits and two palladium-based fragments, {[(tbbpy)2Ru(tmbi)]2[Pd(allyl)]2}2+ (tbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine, tmbi = 5,6,5',6'-tetramethyl-2,2'-bibenzimidazolate), is investigated by means of experimental and theoretical resonance Raman spectroscopy. The calculated spectra, which were obtained within the short-time approximation combined with time-dependent density functional theory (TDDFT), reproduce the experimental spectrum with excellent agreement. We also compared calculations on off-resonance Raman spectra, for which a completely different theoretical approach has to be used, to experimental ones and again found very good agreement. The [Ru2Pd2] complex represents the probably largest system for which a quantum chemical frequency analysis and a calculation of conventional Raman as well as resonance Raman spectra with reasonable basis sets have been performed. A comparison between the resonance Raman spectra of the [Ru2Pd2] complex and its mononuclear [Ru] building block [(tbbpy)2Ru(tmbi)]2+ and a normal-mode analysis reveal that the [Ru2Pd2] resonance Raman spectrum is composed uniquely from peaks arising from the [Ru] fragment. This observation and an analysis of the Kohn-Sham orbitals mainly involved in the initial electronic excitation in the TDDFT description of the [Ru2Pd2] system support the hypothesis that the initial photoexcitation step of [Ru2Pd2] is a charge-transfer excitation from the ruthenium atoms to the adjacent butyl-2,2'-bipyridine ligands.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
May
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| pubmed:issn |
1520-6106
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
31
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| pubmed:volume |
111
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
6078-87
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| pubmed:year |
2007
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| pubmed:articleTitle |
The first photoexcitation step of ruthenium-based models for artificial photosynthesis highlighted by resonance Raman spectroscopy.
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| pubmed:affiliation |
Laboratorium für Physikalische Chemie, ETH Zürich, Zürich, Switzerland.
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| pubmed:publicationType |
Journal Article
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