Eu(III) local coordination in white light emitters organic-inorganic hybrids.

Detalhes bibliográficos
Autor(a) principal: Carlos, L. D.
Data de Publicação: 2001
Outros Autores: Ferreira, RAS, Bermudez, V. D., Bueno, L. A., Molina, C., Messaddeq, Y., Ribeiro, SJL
Tipo de documento: Artigo
Idioma: por
Título da fonte: Repositório Institucional da UNESP
Texto Completo: http://hdl.handle.net/11449/194562
Resumo: Eu3+ luminescence and EXAFS (Extended X-ray Absorption Fine Structure) results are presented for organic-inorganic hybrid gel hosts composed of a siliceous network to which small chains of oxyethylene units are covalently grafted by means of urea bridges. Coordination numbers for Eu3+ ions range from 12.8 to 9.7 with increasing Eu3+ concentration while the Eu3+-first neighbours mean distance is found to be constant at 2.48-2.49 A in the same concentration range. Emission spectra display a broad band in the green/blue spectral region superposed to narrow lines appearing in the yellow/red region in such a way that for the eyes emission appears white. The broad band is assigned to intrinsic NH groups emission and also to electron-hole recombination in the nanosised siliceous domains. The narrow lines are assigned to intra-4f(6), D-5(0)--> F-7(0-4) Eu3+ transitions and from the energy position of the F-7(0-4) levels a mean distance could be calculated for the Eu3+-first neighbours. The calculated results are in good agreement with the experimental ones obtained from EXAFS analysis.
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spelling Eu(III) local coordination in white light emitters organic-inorganic hybrids.organic-inorganic hybridsluminescenceEXAFSEu3+ luminescence and EXAFS (Extended X-ray Absorption Fine Structure) results are presented for organic-inorganic hybrid gel hosts composed of a siliceous network to which small chains of oxyethylene units are covalently grafted by means of urea bridges. Coordination numbers for Eu3+ ions range from 12.8 to 9.7 with increasing Eu3+ concentration while the Eu3+-first neighbours mean distance is found to be constant at 2.48-2.49 A in the same concentration range. Emission spectra display a broad band in the green/blue spectral region superposed to narrow lines appearing in the yellow/red region in such a way that for the eyes emission appears white. The broad band is assigned to intrinsic NH groups emission and also to electron-hole recombination in the nanosised siliceous domains. The narrow lines are assigned to intra-4f(6), D-5(0)--> F-7(0-4) Eu3+ transitions and from the energy position of the F-7(0-4) levels a mean distance could be calculated for the Eu3+-first neighbours. The calculated results are in good agreement with the experimental ones obtained from EXAFS analysis.Univ Aveiro, Dept Fis, P-3810 Aveiro, PortugalUniv Tras Montes & Alto Douro, Dept Quim, P-5001 Vila Real Codex, PortugalUNESP, Inst Quim, BR-14801970 Araraquara, SP, BrazilUNESP, Inst Quim, BR-14801970 Araraquara, SP, BrazilSoc Brasileira QuimicaUniv AveiroUniv Tras Montes & Alto DouroUniversidade Estadual Paulista (Unesp)Carlos, L. D.Ferreira, RASBermudez, V. D.Bueno, L. A.Molina, C.Messaddeq, Y.Ribeiro, SJL2020-12-10T16:30:03Z2020-12-10T16:30:03Z2001-07-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article453-459Quimica Nova. Sao Paulo: Soc Brasileira Quimica, v. 24, n. 4, p. 453-459, 2001.0100-4042http://hdl.handle.net/11449/194562WOS:000170126900005Web of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPporQuimica Novainfo:eu-repo/semantics/openAccess2021-10-22T17:27:45Zoai:repositorio.unesp.br:11449/194562Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T22:23:03.967012Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false
dc.title.none.fl_str_mv Eu(III) local coordination in white light emitters organic-inorganic hybrids.
title Eu(III) local coordination in white light emitters organic-inorganic hybrids.
spellingShingle Eu(III) local coordination in white light emitters organic-inorganic hybrids.
Carlos, L. D.
organic-inorganic hybrids
luminescence
EXAFS
title_short Eu(III) local coordination in white light emitters organic-inorganic hybrids.
title_full Eu(III) local coordination in white light emitters organic-inorganic hybrids.
title_fullStr Eu(III) local coordination in white light emitters organic-inorganic hybrids.
title_full_unstemmed Eu(III) local coordination in white light emitters organic-inorganic hybrids.
title_sort Eu(III) local coordination in white light emitters organic-inorganic hybrids.
author Carlos, L. D.
author_facet Carlos, L. D.
Ferreira, RAS
Bermudez, V. D.
Bueno, L. A.
Molina, C.
Messaddeq, Y.
Ribeiro, SJL
author_role author
author2 Ferreira, RAS
Bermudez, V. D.
Bueno, L. A.
Molina, C.
Messaddeq, Y.
Ribeiro, SJL
author2_role author
author
author
author
author
author
dc.contributor.none.fl_str_mv Univ Aveiro
Univ Tras Montes & Alto Douro
Universidade Estadual Paulista (Unesp)
dc.contributor.author.fl_str_mv Carlos, L. D.
Ferreira, RAS
Bermudez, V. D.
Bueno, L. A.
Molina, C.
Messaddeq, Y.
Ribeiro, SJL
dc.subject.por.fl_str_mv organic-inorganic hybrids
luminescence
EXAFS
topic organic-inorganic hybrids
luminescence
EXAFS
description Eu3+ luminescence and EXAFS (Extended X-ray Absorption Fine Structure) results are presented for organic-inorganic hybrid gel hosts composed of a siliceous network to which small chains of oxyethylene units are covalently grafted by means of urea bridges. Coordination numbers for Eu3+ ions range from 12.8 to 9.7 with increasing Eu3+ concentration while the Eu3+-first neighbours mean distance is found to be constant at 2.48-2.49 A in the same concentration range. Emission spectra display a broad band in the green/blue spectral region superposed to narrow lines appearing in the yellow/red region in such a way that for the eyes emission appears white. The broad band is assigned to intrinsic NH groups emission and also to electron-hole recombination in the nanosised siliceous domains. The narrow lines are assigned to intra-4f(6), D-5(0)--> F-7(0-4) Eu3+ transitions and from the energy position of the F-7(0-4) levels a mean distance could be calculated for the Eu3+-first neighbours. The calculated results are in good agreement with the experimental ones obtained from EXAFS analysis.
publishDate 2001
dc.date.none.fl_str_mv 2001-07-01
2020-12-10T16:30:03Z
2020-12-10T16:30:03Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv Quimica Nova. Sao Paulo: Soc Brasileira Quimica, v. 24, n. 4, p. 453-459, 2001.
0100-4042
http://hdl.handle.net/11449/194562
WOS:000170126900005
identifier_str_mv Quimica Nova. Sao Paulo: Soc Brasileira Quimica, v. 24, n. 4, p. 453-459, 2001.
0100-4042
WOS:000170126900005
url http://hdl.handle.net/11449/194562
dc.language.iso.fl_str_mv por
language por
dc.relation.none.fl_str_mv Quimica Nova
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 453-459
dc.publisher.none.fl_str_mv Soc Brasileira Quimica
publisher.none.fl_str_mv Soc Brasileira Quimica
dc.source.none.fl_str_mv Web of Science
reponame:Repositório Institucional da UNESP
instname:Universidade Estadual Paulista (UNESP)
instacron:UNESP
instname_str Universidade Estadual Paulista (UNESP)
instacron_str UNESP
institution UNESP
reponame_str Repositório Institucional da UNESP
collection Repositório Institucional da UNESP
repository.name.fl_str_mv Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)
repository.mail.fl_str_mv
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