Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca Eu(III) local coordination in white light emitters organic-inorganic hybrids
<abstract language="eng">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. Coo...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Química
2001-08-01
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| Series: | Química Nova |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422001000400005 |
| _version_ | 1818884580907679744 |
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| author | Luís D. Carlos Rute A. Sá Ferreira Verónica de Zéa Bermudez Luciano A. Bueno Celso Molina Younes Messaddeq Sidney J. L. Ribeiro |
| author_facet | Luís D. Carlos Rute A. Sá Ferreira Verónica de Zéa Bermudez Luciano A. Bueno Celso Molina Younes Messaddeq Sidney J. L. Ribeiro |
| author_sort | Luís D. Carlos |
| collection | DOAJ |
| description | <abstract language="eng">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. |
| first_indexed | 2024-12-19T15:51:49Z |
| format | Article |
| id | doaj.art-01a2e30817334512bbf2b4fb60ea1f44 |
| institution | Directory Open Access Journal |
| issn | 0100-4042 1678-7064 |
| language | English |
| last_indexed | 2024-12-19T15:51:49Z |
| publishDate | 2001-08-01 |
| publisher | Sociedade Brasileira de Química |
| record_format | Article |
| series | Química Nova |
| spelling | doaj.art-01a2e30817334512bbf2b4fb60ea1f442022-12-21T20:15:12ZengSociedade Brasileira de QuímicaQuímica Nova0100-40421678-70642001-08-0124445345910.1590/S0100-40422001000400005Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca Eu(III) local coordination in white light emitters organic-inorganic hybridsLuís D. CarlosRute A. Sá FerreiraVerónica de Zéa BermudezLuciano A. BuenoCelso MolinaYounes MessaddeqSidney J. L. Ribeiro<abstract language="eng">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.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422001000400005organic-inorganic hybridsluminescenceEXAFS |
| spellingShingle | Luís D. Carlos Rute A. Sá Ferreira Verónica de Zéa Bermudez Luciano A. Bueno Celso Molina Younes Messaddeq Sidney J. L. Ribeiro Coordenação local do Eu(III) em híbridos orgânicos/inorgânicos emissores de luz branca Eu(III) local coordination in white light emitters organic-inorganic hybrids Química Nova organic-inorganic hybrids luminescence EXAFS |
| title | 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_full | 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_fullStr | 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_full_unstemmed | 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_short | 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_sort | coordenacao local do eu iii em hibridos organicos inorganicos emissores de luz branca eu iii local coordination in white light emitters organic inorganic hybrids |
| topic | organic-inorganic hybrids luminescence EXAFS |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422001000400005 |
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