Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide
Autor(a) principal: | |
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Data de Publicação: | 2013 |
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/10316/80830 https://doi.org/10.1016/j.jphotochem.2013.05.009 |
Resumo: | The photophysical properties of the widely used plant growth regulator 2-(1-naphthyl) acetamide (NAD) were studied in water and representative organic solvents (ethanol, ethylene glycol, acetonitrile, chloroform, 1,4-dioxane) employing steady-state and time-resolved spectroscopy. Quantum yields and lifetimes of fluorescence, phosphorescence and triplet formation and triplet–triplet absorption spectra were obtained. From these, all radiative and radiationless rate constants have been determined, together with singlet and triplet excited state energies (4.00 and 2.69 eV, respectively). The fluorescence quantum yield and lifetime increased on going from water (ΦF 0.066, τF 35.0 ns) to non-hydrogen bonding solvents (ΦF 0.357, τF 51.0 ns in 1,4-dioxane), probably due to decreased internal conversion. Fluorescence was quenched by several anions through an electron transfer process. A limit on the reduction potential of 1NAD* of E0 2.1 ± 0.2 V was estimated. The attribution of the transient absorption seen in nanosecond laser flash photolysis to 3NAD* was confirmed by energy transfer and oxygen quenching. Quenching of triplet states leads to singlet oxygen formation, with quantum yields varying from 0.097 in water to 0.396 in chloroform. However, these are lower than the triplet state quantum yields, particularly in water (ΦT 0.424), indicating competing quenching pathways, probably involving electron transfer. The relevance of these results to the photoreactivity of NAD under environmental conditions is discussed. |
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Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide2-(1-Naphthyl) acetamideExcited statesSolvent polarityNanosecond laser flash photolysisFluorescenceThe photophysical properties of the widely used plant growth regulator 2-(1-naphthyl) acetamide (NAD) were studied in water and representative organic solvents (ethanol, ethylene glycol, acetonitrile, chloroform, 1,4-dioxane) employing steady-state and time-resolved spectroscopy. Quantum yields and lifetimes of fluorescence, phosphorescence and triplet formation and triplet–triplet absorption spectra were obtained. From these, all radiative and radiationless rate constants have been determined, together with singlet and triplet excited state energies (4.00 and 2.69 eV, respectively). The fluorescence quantum yield and lifetime increased on going from water (ΦF 0.066, τF 35.0 ns) to non-hydrogen bonding solvents (ΦF 0.357, τF 51.0 ns in 1,4-dioxane), probably due to decreased internal conversion. Fluorescence was quenched by several anions through an electron transfer process. A limit on the reduction potential of 1NAD* of E0 2.1 ± 0.2 V was estimated. The attribution of the transient absorption seen in nanosecond laser flash photolysis to 3NAD* was confirmed by energy transfer and oxygen quenching. Quenching of triplet states leads to singlet oxygen formation, with quantum yields varying from 0.097 in water to 0.396 in chloroform. However, these are lower than the triplet state quantum yields, particularly in water (ΦT 0.424), indicating competing quenching pathways, probably involving electron transfer. The relevance of these results to the photoreactivity of NAD under environmental conditions is discussed.Elsevier2013-08-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/80830http://hdl.handle.net/10316/80830https://doi.org/10.1016/j.jphotochem.2013.05.009engSILVA, Eliana Sousa da [et. al] - Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide. "Journal of Photochemistry and Photobiology A: Chemistry". ISSN 1010-6030. Vol. 265 (2013) p. 29-401010-6030http://www.sciencedirect.com/science/article/pii/S1010603013002220Wong-Wah-Chung, PascalSarakha, MohamedBurrows, Hugh D.Silva, Eliana Sousa dainfo: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:RCAAP2021-10-27T09:31:55Zoai:estudogeral.uc.pt:10316/80830Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:03:06.719927Repositório 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 |
Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide |
title |
Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide |
spellingShingle |
Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide Wong-Wah-Chung, Pascal 2-(1-Naphthyl) acetamide Excited states Solvent polarity Nanosecond laser flash photolysis Fluorescence |
title_short |
Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide |
title_full |
Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide |
title_fullStr |
Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide |
title_full_unstemmed |
Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide |
title_sort |
Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide |
author |
Wong-Wah-Chung, Pascal |
author_facet |
Wong-Wah-Chung, Pascal Sarakha, Mohamed Burrows, Hugh D. Silva, Eliana Sousa da |
author_role |
author |
author2 |
Sarakha, Mohamed Burrows, Hugh D. Silva, Eliana Sousa da |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Wong-Wah-Chung, Pascal Sarakha, Mohamed Burrows, Hugh D. Silva, Eliana Sousa da |
dc.subject.por.fl_str_mv |
2-(1-Naphthyl) acetamide Excited states Solvent polarity Nanosecond laser flash photolysis Fluorescence |
topic |
2-(1-Naphthyl) acetamide Excited states Solvent polarity Nanosecond laser flash photolysis Fluorescence |
description |
The photophysical properties of the widely used plant growth regulator 2-(1-naphthyl) acetamide (NAD) were studied in water and representative organic solvents (ethanol, ethylene glycol, acetonitrile, chloroform, 1,4-dioxane) employing steady-state and time-resolved spectroscopy. Quantum yields and lifetimes of fluorescence, phosphorescence and triplet formation and triplet–triplet absorption spectra were obtained. From these, all radiative and radiationless rate constants have been determined, together with singlet and triplet excited state energies (4.00 and 2.69 eV, respectively). The fluorescence quantum yield and lifetime increased on going from water (ΦF 0.066, τF 35.0 ns) to non-hydrogen bonding solvents (ΦF 0.357, τF 51.0 ns in 1,4-dioxane), probably due to decreased internal conversion. Fluorescence was quenched by several anions through an electron transfer process. A limit on the reduction potential of 1NAD* of E0 2.1 ± 0.2 V was estimated. The attribution of the transient absorption seen in nanosecond laser flash photolysis to 3NAD* was confirmed by energy transfer and oxygen quenching. Quenching of triplet states leads to singlet oxygen formation, with quantum yields varying from 0.097 in water to 0.396 in chloroform. However, these are lower than the triplet state quantum yields, particularly in water (ΦT 0.424), indicating competing quenching pathways, probably involving electron transfer. The relevance of these results to the photoreactivity of NAD under environmental conditions is discussed. |
publishDate |
2013 |
dc.date.none.fl_str_mv |
2013-08-01 |
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/10316/80830 http://hdl.handle.net/10316/80830 https://doi.org/10.1016/j.jphotochem.2013.05.009 |
url |
http://hdl.handle.net/10316/80830 https://doi.org/10.1016/j.jphotochem.2013.05.009 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
SILVA, Eliana Sousa da [et. al] - Photophysical characterization of the plant growth regulator 2-(1-naphthyl) acetamide. "Journal of Photochemistry and Photobiology A: Chemistry". ISSN 1010-6030. Vol. 265 (2013) p. 29-40 1010-6030 http://www.sciencedirect.com/science/article/pii/S1010603013002220 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Elsevier |
publisher.none.fl_str_mv |
Elsevier |
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 |
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1799133923597352960 |