Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca

Detalhes bibliográficos
Autor(a) principal: Carlos,Luís D.
Data de Publicação: 2001
Outros Autores: Ferreira,Rute A. Sá, Zéa Bermudez,Verónica de, Bueno,Luciano A., Molina,Celso, Messaddeq,Younes, Ribeiro,Sidney J. L.
Tipo de documento: Artigo
Idioma: por
Título da fonte: Química Nova (Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422001000400005
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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spelling Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz brancaorganic-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.Sociedade Brasileira de Química2001-08-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422001000400005Química Nova v.24 n.4 2001reponame:Química Nova (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0100-40422001000400005info:eu-repo/semantics/openAccessCarlos,Luís D.Ferreira,Rute A. SáZéa Bermudez,Verónica deBueno,Luciano A.Molina,CelsoMessaddeq,YounesRibeiro,Sidney J. L.por2001-08-31T00:00:00Zoai:scielo:S0100-40422001000400005Revistahttps://www.scielo.br/j/qn/ONGhttps://old.scielo.br/oai/scielo-oai.phpquimicanova@sbq.org.br1678-70640100-4042opendoar:2001-08-31T00:00Química Nova (Online) - Sociedade Brasileira de Química (SBQ)false
dc.title.none.fl_str_mv Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca
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.
Molina,Celso
Messaddeq,Younes
Ribeiro,Sidney J. L.
author_role author
author2 Ferreira,Rute A. Sá
Zéa Bermudez,Verónica de
Bueno,Luciano A.
Molina,Celso
Messaddeq,Younes
Ribeiro,Sidney J. L.
author2_role author
author
author
author
author
author
dc.contributor.author.fl_str_mv Carlos,Luís D.
Ferreira,Rute A. Sá
Zéa Bermudez,Verónica de
Bueno,Luciano A.
Molina,Celso
Messaddeq,Younes
Ribeiro,Sidney J. L.
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
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422001000400005
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422001000400005
dc.language.iso.fl_str_mv por
language por
dc.relation.none.fl_str_mv 10.1590/S0100-40422001000400005
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
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 Química Nova v.24 n.4 2001
reponame:Química Nova (Online)
instname:Sociedade Brasileira de Química (SBQ)
instacron:SBQ
instname_str Sociedade Brasileira de Química (SBQ)
instacron_str SBQ
institution SBQ
reponame_str Química Nova (Online)
collection Química Nova (Online)
repository.name.fl_str_mv Química Nova (Online) - Sociedade Brasileira de Química (SBQ)
repository.mail.fl_str_mv quimicanova@sbq.org.br
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