Eu(III) local coordination in white light emitters organic-inorganic hybrids.
Autor(a) principal: | |
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Data de Publicação: | 2001 |
Outros Autores: | , , , , , |
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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Repositório Institucional da UNESP |
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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 |
|
_version_ |
1808129422391246848 |