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dc.contributor.author
Kuzmanich, Gregory
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Simoncelli, Sabrina
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Gard, Matthew N.
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Spänig, Fabian
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Henderson, Bryana L.
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Guldi, Dirk M.
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Garcia Garibay, Miguel A.
dc.date.available
2019-02-06T17:31:35Z
dc.date.issued
2011-11
dc.identifier.citation
Kuzmanich, Gregory; Simoncelli, Sabrina; Gard, Matthew N.; Spänig, Fabian; Henderson, Bryana L.; et al.; Excited state kinetics in crystalline solids: Self-quenching in nanocrystals of 4,4′-disubstituted benzophenone triplets occurs by a reductive quenching mechanism; American Chemical Society; Journal of the American Chemical Society; 133; 43; 11-2011; 17296-17306
dc.identifier.issn
0002-7863
dc.identifier.uri
http://hdl.handle.net/11336/69533
dc.description.abstract
We report an efficient triplet state self-quenching mechanism in crystals of eight benzophenones, which included the parent structure (1), six 4,4′-disubstituted compounds with NH 2 (2), NMe 2 (3), OH (4), OMe (5), COOH (6), and COOMe (7), and benzophenone-3,3′,4, 4′-tetracarboxylic dianhydride (8). Self-quenching effects were determined by measuring their triplet-triplet lifetimes and spectra using femtosecond and nanosecond transient absorption measurements with nanocrystalline suspensions. When possible, triplet lifetimes were confirmed by measuring the phosphorescence lifetimes and with the help of diffusion-limited quenching with iodide ions. We were surprised to discover that the triplet lifetimes of substituted benzophenones in crystals vary over 9 orders of magnitude from ca. 62 ps to 1 ms. In contrast to nanocrystalline suspensions, the lifetimes in solution only vary over 3 orders of magnitude (1-1000 μs). Analysis of the rate constants of quenching show that the more electron-rich benzophenones are the most efficiently deactivated such that there is an excellent correlation, ρ = -2.85, between the triplet quenching rate constants and the Hammet θ + values for the 4,4′ substituents. Several crystal structures indicate the existence of near-neighbor arrangements that deviate from the proposed ideal for "n-type" quenching, suggesting that charge transfer quenching is mediated by a relatively loose arrangement. © 2011 American Chemical Society.
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application/pdf
dc.language.iso
eng
dc.publisher
American Chemical Society
dc.rights
info:eu-repo/semantics/openAccess
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https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
4,4'-Disubstituted Benzophenone
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Nanocrystals
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Self-Quenching
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Triplets
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Otras Ciencias Químicas
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Ciencias Químicas
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CIENCIAS NATURALES Y EXACTAS
dc.title
Excited state kinetics in crystalline solids: Self-quenching in nanocrystals of 4,4′-disubstituted benzophenone triplets occurs by a reductive quenching mechanism
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2019-01-09T14:21:29Z
dc.journal.volume
133
dc.journal.number
43
dc.journal.pagination
17296-17306
dc.journal.pais
Estados Unidos
dc.journal.ciudad
Washington
dc.description.fil
Fil: Kuzmanich, Gregory. University of California at Los Angeles; Estados Unidos
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Fil: Simoncelli, Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Inorgánica, Analítica y Química Física; Argentina
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Fil: Gard, Matthew N.. University of California at Los Angeles; Estados Unidos
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Fil: Spänig, Fabian. Friedrich Alexander Universität Erlangen; Alemania
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Fil: Henderson, Bryana L.. University of California at Los Angeles; Estados Unidos
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Fil: Guldi, Dirk M.. Friedrich Alexander Universität Erlangen; Alemania
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Fil: Garcia Garibay, Miguel A.. University of California at Los Angeles; Estados Unidos
dc.journal.title
Journal of the American Chemical Society
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/abs/10.1021/ja204927s
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/https://dx.doi.org/10.1021/ja204927s
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