Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OT
Autor(a) principal: | |
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Data de Publicação: | 2004 |
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/10316/10280 https://doi.org/10.1021/jp037901p |
Resumo: | The aggregation process of meso-tetra(4-aminosulfonylphenyl)porphyrin (PC0), of butyl and dodecyl derivatives (PC4 and PC12, respectively) in the presence of aerosol-OT (AOT) reversed micelles with different values of ω0 = [water]/[AOT] was investigated using steady-state extinction, fluorescence, and resonance light scattering (RLS) techniques. The scattering has been accounted for and the absorption spectra corrected from the extinction spectra. In homogeneous solutions, the porphyrins exist as a monomer showing the Soret band around 420 nm and emission bands at 650 and 716 nm. In reverse micelles, the spectra vary according to the chain length and the amount of solubilized water. Only PC12 is dissolved as a monomer at ω0 = 0, and PC4 shows some degree of aggregation. PC0 is present largely as an aggregate. At ω0 ≠ 0, a complete aggregation is observed for PC4 and PC12, whereas in PC0, some degree of disaggregation was detected. The extinction spectra of PC0 and PC4 in aggregate forms show a broad and red shifted Soret band indicating J aggregates. By contrast, the Soret band intensity of PC12 decreases and a new band around 376 nm appears with a broadening of the monomer Soret band which reflects H aggregates. RLS shows a strong signal for PC12 at red spectral region at high ω0 indicating J aggregate types. The fluorescence spectra showed the new band around 670 nm for PC0 and PC12, whereas in PC4, only blue shifted bands were observed with ω0 increase. The global fluorescence quantum yield of the PC12 aggregates is lower than the respective monomer. The aggregate sizes were followed by RLS measurements which showed an increase of intensity at around 440 nm. The aggregation dynamics is dependent on both the porphyrin concentration and ω0. |
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Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OTThe aggregation process of meso-tetra(4-aminosulfonylphenyl)porphyrin (PC0), of butyl and dodecyl derivatives (PC4 and PC12, respectively) in the presence of aerosol-OT (AOT) reversed micelles with different values of ω0 = [water]/[AOT] was investigated using steady-state extinction, fluorescence, and resonance light scattering (RLS) techniques. The scattering has been accounted for and the absorption spectra corrected from the extinction spectra. In homogeneous solutions, the porphyrins exist as a monomer showing the Soret band around 420 nm and emission bands at 650 and 716 nm. In reverse micelles, the spectra vary according to the chain length and the amount of solubilized water. Only PC12 is dissolved as a monomer at ω0 = 0, and PC4 shows some degree of aggregation. PC0 is present largely as an aggregate. At ω0 ≠ 0, a complete aggregation is observed for PC4 and PC12, whereas in PC0, some degree of disaggregation was detected. The extinction spectra of PC0 and PC4 in aggregate forms show a broad and red shifted Soret band indicating J aggregates. By contrast, the Soret band intensity of PC12 decreases and a new band around 376 nm appears with a broadening of the monomer Soret band which reflects H aggregates. RLS shows a strong signal for PC12 at red spectral region at high ω0 indicating J aggregate types. The fluorescence spectra showed the new band around 670 nm for PC0 and PC12, whereas in PC4, only blue shifted bands were observed with ω0 increase. The global fluorescence quantum yield of the PC12 aggregates is lower than the respective monomer. The aggregate sizes were followed by RLS measurements which showed an increase of intensity at around 440 nm. The aggregation dynamics is dependent on both the porphyrin concentration and ω0.American Chemical Society2004-08-05info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/10280http://hdl.handle.net/10316/10280https://doi.org/10.1021/jp037901pengThe Journal of Physical Chemistry B. 108:31 (2004) 11344-113561520-6106Togashi, Denisio M.Costa, Sílvia M. B.Sobral, Abílio J. F. N.Gonçalves, A. M. d'A. R.info: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:RCAAP2020-05-25T13:13:10Zoai:estudogeral.uc.pt:10316/10280Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:11.197759Repositório 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 |
Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OT |
title |
Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OT |
spellingShingle |
Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OT Togashi, Denisio M. |
title_short |
Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OT |
title_full |
Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OT |
title_fullStr |
Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OT |
title_full_unstemmed |
Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OT |
title_sort |
Self-Aggregation of Lipophilic Porphyrins in Reverse Micelles of Aerosol OT |
author |
Togashi, Denisio M. |
author_facet |
Togashi, Denisio M. Costa, Sílvia M. B. Sobral, Abílio J. F. N. Gonçalves, A. M. d'A. R. |
author_role |
author |
author2 |
Costa, Sílvia M. B. Sobral, Abílio J. F. N. Gonçalves, A. M. d'A. R. |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Togashi, Denisio M. Costa, Sílvia M. B. Sobral, Abílio J. F. N. Gonçalves, A. M. d'A. R. |
description |
The aggregation process of meso-tetra(4-aminosulfonylphenyl)porphyrin (PC0), of butyl and dodecyl derivatives (PC4 and PC12, respectively) in the presence of aerosol-OT (AOT) reversed micelles with different values of ω0 = [water]/[AOT] was investigated using steady-state extinction, fluorescence, and resonance light scattering (RLS) techniques. The scattering has been accounted for and the absorption spectra corrected from the extinction spectra. In homogeneous solutions, the porphyrins exist as a monomer showing the Soret band around 420 nm and emission bands at 650 and 716 nm. In reverse micelles, the spectra vary according to the chain length and the amount of solubilized water. Only PC12 is dissolved as a monomer at ω0 = 0, and PC4 shows some degree of aggregation. PC0 is present largely as an aggregate. At ω0 ≠ 0, a complete aggregation is observed for PC4 and PC12, whereas in PC0, some degree of disaggregation was detected. The extinction spectra of PC0 and PC4 in aggregate forms show a broad and red shifted Soret band indicating J aggregates. By contrast, the Soret band intensity of PC12 decreases and a new band around 376 nm appears with a broadening of the monomer Soret band which reflects H aggregates. RLS shows a strong signal for PC12 at red spectral region at high ω0 indicating J aggregate types. The fluorescence spectra showed the new band around 670 nm for PC0 and PC12, whereas in PC4, only blue shifted bands were observed with ω0 increase. The global fluorescence quantum yield of the PC12 aggregates is lower than the respective monomer. The aggregate sizes were followed by RLS measurements which showed an increase of intensity at around 440 nm. The aggregation dynamics is dependent on both the porphyrin concentration and ω0. |
publishDate |
2004 |
dc.date.none.fl_str_mv |
2004-08-05 |
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/10316/10280 http://hdl.handle.net/10316/10280 https://doi.org/10.1021/jp037901p |
url |
http://hdl.handle.net/10316/10280 https://doi.org/10.1021/jp037901p |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
The Journal of Physical Chemistry B. 108:31 (2004) 11344-11356 1520-6106 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
American Chemical Society |
publisher.none.fl_str_mv |
American Chemical Society |
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 |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799133904314040320 |