Source:http://linkedlifedata.com/resource/pubmed/id/15643893
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2
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| pubmed:dateCreated |
2005-1-12
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| pubmed:abstractText |
Electronic absorption and resonance-enhanced Raman spectra for ketimido (azavinylidene) complexes of tetravalent uranium, (C(5)Me(5))(2)U[-N=C(Ph)(R)](2) (R = Ph, Me, and CH(2)Ph), have been recorded. The absorption spectra exhibit four broad bands between 13 000 and 24 000 cm(-1). The highest-energy band is assigned to the ketimido-localized p( perpendicular)(N)-->pi(N=C) transition based on comparison to the spectra of (C(5)H(5))(2)Zr[-N=CPh(2)](2) and (C(5)Me(5))(2)Th[-N=CPh(2)](2). Upon excitation into any of these four absorption bands, the (C(5)Me(5))(2)U[-N=C(Ph)(R)](2) complexes exhibit resonance enhancement for several Raman bands attributable to vibrations of the ketimido ligands. Raman bands for both the symmetric and nominally asymmetric N=C stretching bands are resonantly enhanced upon excitation into the p( perpendicular)(N)-->pi(N=C) absorption bands, indicating that the excited state is localized on a single ketimido ligand. Raman excitation profiles for (C(5)Me(5))(2)U[-N=CPh(2)](2) confirm that at least one of the lower-energy electronic absorption bands (E(max) approximately 16300 cm(-1)) is a charge-transfer transition between the U(IV) center and the ketimido ligand(s). The observations of both charge-transfer transitions and resonance enhancement of Raman vibrational bands are exceedingly rare for tetravalent actinide complexes and reflect the strong bonding interactions between the uranium 5f/6d orbitals and those on the ketimido 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 |
Jan
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| pubmed:issn |
0002-7863
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
19
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| pubmed:volume |
127
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
682-9
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| pubmed:year |
2005
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| pubmed:articleTitle |
Molecular spectroscopy of uranium(IV) bis(ketimido) complexes. rare observation of resonance-enhanced raman scattering from organoactinide complexes and evidence for broken-symmetry excited states.
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| pubmed:affiliation |
Chemistry Division and the Glenn T. Seaborg Institute for Transactinium Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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| pubmed:publicationType |
Journal Article
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