Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca
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://dx.doi.org/10.1590/S0100-40422001000400005 http://hdl.handle.net/11449/27574 |
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 Å 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-4f6, 5D0->7F0-4 Eu3+ transitions and from the energy position of the 7F0-4 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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Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz brancaEu(III) local coordination in white light emitters organic-inorganic hybridsorganic-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 Å 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-4f6, 5D0->7F0-4 Eu3+ transitions and from the energy position of the 7F0-4 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.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade de Aveiro Departamento de FísicaUniversidade de Trás-os-Montes e Alto Douro Departamento de QuímicaUniversidade Estadual Paulista Instituto de QuímicaUniversidade Estadual Paulista Instituto de QuímicaSociedade Brasileira de QuímicaUniversidade de Aveiro Departamento de FísicaUniversidade de Trás-os-Montes e Alto Douro Departamento de QuímicaUniversidade Estadual Paulista (Unesp)Carlos, Luís D.Ferreira, Rute A. SáZéa Bermudez, Verónica deBueno, Luciano A. [UNESP]Molina, Celso [UNESP]Messaddeq, Younes [UNESP]Ribeiro, Sidney José Lima [UNESP]2014-05-20T15:10:18Z2014-05-20T15:10:18Z2001-08-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article453-459application/pdfhttp://dx.doi.org/10.1590/S0100-40422001000400005Química Nova. Sociedade Brasileira de Química, v. 24, n. 4, p. 453-459, 2001.0100-4042http://hdl.handle.net/11449/2757410.1590/S0100-40422001000400005S0100-40422001000400005S0100-40422001000400005.pdf299850384191781564460474630346540000-0003-3286-9440SciELOreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPporQuímica Nova0.6460,255info:eu-repo/semantics/openAccess2023-12-30T06:21:57Zoai:repositorio.unesp.br:11449/27574Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T21:43:29.636311Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca Eu(III) local coordination in white light emitters organic-inorganic hybrids |
title |
Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca |
spellingShingle |
Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca Carlos, Luís D. organic-inorganic hybrids luminescence EXAFS |
title_short |
Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca |
title_full |
Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca |
title_fullStr |
Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca |
title_full_unstemmed |
Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca |
title_sort |
Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca |
author |
Carlos, Luís D. |
author_facet |
Carlos, Luís D. Ferreira, Rute A. Sá Zéa Bermudez, Verónica de Bueno, Luciano A. [UNESP] Molina, Celso [UNESP] Messaddeq, Younes [UNESP] Ribeiro, Sidney José Lima [UNESP] |
author_role |
author |
author2 |
Ferreira, Rute A. Sá Zéa Bermudez, Verónica de Bueno, Luciano A. [UNESP] Molina, Celso [UNESP] Messaddeq, Younes [UNESP] Ribeiro, Sidney José Lima [UNESP] |
author2_role |
author author author author author author |
dc.contributor.none.fl_str_mv |
Universidade de Aveiro Departamento de Física Universidade de Trás-os-Montes e Alto Douro Departamento de Química Universidade Estadual Paulista (Unesp) |
dc.contributor.author.fl_str_mv |
Carlos, Luís D. Ferreira, Rute A. Sá Zéa Bermudez, Verónica de Bueno, Luciano A. [UNESP] Molina, Celso [UNESP] Messaddeq, Younes [UNESP] Ribeiro, Sidney José Lima [UNESP] |
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 Å 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-4f6, 5D0->7F0-4 Eu3+ transitions and from the energy position of the 7F0-4 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 |
2001-08-01 2014-05-20T15:10:18Z 2014-05-20T15:10:18Z |
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 |
http://dx.doi.org/10.1590/S0100-40422001000400005 Química Nova. Sociedade Brasileira de Química, v. 24, n. 4, p. 453-459, 2001. 0100-4042 http://hdl.handle.net/11449/27574 10.1590/S0100-40422001000400005 S0100-40422001000400005 S0100-40422001000400005.pdf 2998503841917815 6446047463034654 0000-0003-3286-9440 |
url |
http://dx.doi.org/10.1590/S0100-40422001000400005 http://hdl.handle.net/11449/27574 |
identifier_str_mv |
Química Nova. Sociedade Brasileira de Química, v. 24, n. 4, p. 453-459, 2001. 0100-4042 10.1590/S0100-40422001000400005 S0100-40422001000400005 S0100-40422001000400005.pdf 2998503841917815 6446047463034654 0000-0003-3286-9440 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.none.fl_str_mv |
Química Nova 0.646 0,255 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
453-459 application/pdf |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
SciELO 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_ |
1808129350210420736 |