Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10316/41708 https://doi.org/10.1002/cphc.201601236 |
Resumo: | Steady-state and time-resolved absorption and fluorescence measurements are reported for Congo Red (CR) in aqueous and dimethylsulfoxide (DMSO) solutions. The very low fluorescence quantum yield (≈10(-4) ) for CR in dilute solutions together with the absence of a triplet state indicates that internal conversion is the dominant deactivation route with more than 99.99 % of the quanta loss (attributed to the energy gap law for radiationless transitions). Although no direct evidence for trans-cis photoisomerization was obtained from absorption or fluorescence data, the global analysis of fs-transient absorption data indicates the presence of a photoproduct with a lifetime of ≈170 ps that is suggested to be associated with such a process. Spectral data for more concentrated CR solutions indicate the presence of oblique or twisted J-type aggregates. These results are compared with spectra for CR in the solid state (sodium salt) and intercalated in a layered double hydroxide via a one-step co-precipitation route. Powder XRD and electronic spectral data for the nanohybrid indicate that the CR guest molecules are intercalated as a monolayer consisting of slipped cofacial J-type aggregates. |
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Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid StateSteady-state and time-resolved absorption and fluorescence measurements are reported for Congo Red (CR) in aqueous and dimethylsulfoxide (DMSO) solutions. The very low fluorescence quantum yield (≈10(-4) ) for CR in dilute solutions together with the absence of a triplet state indicates that internal conversion is the dominant deactivation route with more than 99.99 % of the quanta loss (attributed to the energy gap law for radiationless transitions). Although no direct evidence for trans-cis photoisomerization was obtained from absorption or fluorescence data, the global analysis of fs-transient absorption data indicates the presence of a photoproduct with a lifetime of ≈170 ps that is suggested to be associated with such a process. Spectral data for more concentrated CR solutions indicate the presence of oblique or twisted J-type aggregates. These results are compared with spectra for CR in the solid state (sodium salt) and intercalated in a layered double hydroxide via a one-step co-precipitation route. Powder XRD and electronic spectral data for the nanohybrid indicate that the CR guest molecules are intercalated as a monolayer consisting of slipped cofacial J-type aggregates.2017info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/41708http://hdl.handle.net/10316/41708https://doi.org/10.1002/cphc.201601236enghttp://onlinelibrary.wiley.com/doi/10.1002/cphc.201601236/fullCosta, Ana L.Gomes, Ana C.Pillinger, MartynGonçalves, Isabel S.Pina, JoãoSeixas de Melo, J. Sérgioinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2021-06-29T10:02:46Zoai:estudogeral.uc.pt:10316/41708Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:50.953392Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State |
title |
Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State |
spellingShingle |
Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State Costa, Ana L. |
title_short |
Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State |
title_full |
Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State |
title_fullStr |
Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State |
title_full_unstemmed |
Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State |
title_sort |
Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State |
author |
Costa, Ana L. |
author_facet |
Costa, Ana L. Gomes, Ana C. Pillinger, Martyn Gonçalves, Isabel S. Pina, João Seixas de Melo, J. Sérgio |
author_role |
author |
author2 |
Gomes, Ana C. Pillinger, Martyn Gonçalves, Isabel S. Pina, João Seixas de Melo, J. Sérgio |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Costa, Ana L. Gomes, Ana C. Pillinger, Martyn Gonçalves, Isabel S. Pina, João Seixas de Melo, J. Sérgio |
description |
Steady-state and time-resolved absorption and fluorescence measurements are reported for Congo Red (CR) in aqueous and dimethylsulfoxide (DMSO) solutions. The very low fluorescence quantum yield (≈10(-4) ) for CR in dilute solutions together with the absence of a triplet state indicates that internal conversion is the dominant deactivation route with more than 99.99 % of the quanta loss (attributed to the energy gap law for radiationless transitions). Although no direct evidence for trans-cis photoisomerization was obtained from absorption or fluorescence data, the global analysis of fs-transient absorption data indicates the presence of a photoproduct with a lifetime of ≈170 ps that is suggested to be associated with such a process. Spectral data for more concentrated CR solutions indicate the presence of oblique or twisted J-type aggregates. These results are compared with spectra for CR in the solid state (sodium salt) and intercalated in a layered double hydroxide via a one-step co-precipitation route. Powder XRD and electronic spectral data for the nanohybrid indicate that the CR guest molecules are intercalated as a monolayer consisting of slipped cofacial J-type aggregates. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017 |
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://hdl.handle.net/10316/41708 http://hdl.handle.net/10316/41708 https://doi.org/10.1002/cphc.201601236 |
url |
http://hdl.handle.net/10316/41708 https://doi.org/10.1002/cphc.201601236 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
http://onlinelibrary.wiley.com/doi/10.1002/cphc.201601236/full |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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