Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200

Detalhes bibliográficos
Autor(a) principal: Brinn, Ira Mark
Data de Publicação: 2008
Outros Autores: Rosa, Mauricio Ferreira
Tipo de documento: Artigo
Idioma: por
Título da fonte: Acta scientiarum. Technology (Online)
Texto Completo: http://www.periodicos.uem.br/ojs/index.php/ActaSciTechnol/article/view/1200
Resumo: By using the steady-state spectroscopy technique, it was possible to determine the acidity constants of 2.7-naphthalenediol (27ND) in the ground (pKa) and excited states (pKa*). The results of pKa and pKa* obtained, were respectively 9.54 and 6.5. This last value is in poor agreement with the values previously reported. Allying time-correlated single photon counting (TCSPC) experiments and kinetic model calculations made possible to determine, for the first time, the rate constants for the protonic dissociation of 27ND, in the first excited singlet state. The rate constants obtained are: k1 = 1.1x108s-1; k2 = 2.9x108 s-1; k3 = 7.4x108 s-1; kd1 = 8.0x107 M-1s-1; kr1 = 5.0x1010 M-1s-1 and kd2 = 1.0x107 M-1s-1. The acidity constant in the first excited singlet state (pKa*) calculated by the kinetic method (ratio of kd1 and kr1) was 2.8. This value is in best agreement with the ones previously reported in the literature obtained by graphic methods
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spelling Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200Determinação das constantes de dissociação protônica do 2,7-naftalenodiol no primeiro estado excitado singlete por experimentos com resolução temporal e modelagem matemática - DOI: 10.4025/actascitechnol.v28i1.120027-naphthanediolpKa measurementskinetic modelingfluorescence decay27-naftalenodiolmedidas de pKamodelagem cinéticadecaimento de fluorescência1.06.00.00-0 QuímicaBy using the steady-state spectroscopy technique, it was possible to determine the acidity constants of 2.7-naphthalenediol (27ND) in the ground (pKa) and excited states (pKa*). The results of pKa and pKa* obtained, were respectively 9.54 and 6.5. This last value is in poor agreement with the values previously reported. Allying time-correlated single photon counting (TCSPC) experiments and kinetic model calculations made possible to determine, for the first time, the rate constants for the protonic dissociation of 27ND, in the first excited singlet state. The rate constants obtained are: k1 = 1.1x108s-1; k2 = 2.9x108 s-1; k3 = 7.4x108 s-1; kd1 = 8.0x107 M-1s-1; kr1 = 5.0x1010 M-1s-1 and kd2 = 1.0x107 M-1s-1. The acidity constant in the first excited singlet state (pKa*) calculated by the kinetic method (ratio of kd1 and kr1) was 2.8. This value is in best agreement with the ones previously reported in the literature obtained by graphic methodsAtravés do emprego de técnicas no estado estacionário foram determinadas as primeiras constantes de acidez nos estados fundamental (pKa) e excitado (pKa*) para o 2,7-naftalenodiol (27ND). Os valores de pKa e pKa* obtidos foram respectivamente 9,54 e 6,5. Este último valor não apresentou boa concordância com resultados experimentais anteriormente relatados . Aliando-se experimentos com resolução em tempo (decaimento de fluorescência) e cálculos de modelagem cinética foi possível determinar, pela primeira vez, todas as constantes cinéticas envolvidas no processo de dissociação protônica no primeiro estado excitado singlete do 27ND. As constantes cinéticas obtidas foram: k1 = 1,1x108s-1; k2 = 2,9x108 s-1; k3 = 7,4x108 s-1; kd1 = 8,0x107 M-1s-1; kr1 = 5,0x1010 M-1s-1 e kd2 = 1x107 M-1s-1. Calculando-se a razão entre kd1 e kr1 obteve-se a primeira constante de acidez no estado excitado singlete (pKa*) pelo método cinético, sendo obtido o valor de pKa* = 2,8. Este valor está em ótima concordância com os valores relatados na literatura, obtidos por outros métodosUniversidade Estadual De Maringá2008-03-20info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttp://www.periodicos.uem.br/ojs/index.php/ActaSciTechnol/article/view/120010.4025/actascitechnol.v28i1.1200Acta Scientiarum. Technology; Vol 28 No 1 (2006); 5-12Acta Scientiarum. Technology; v. 28 n. 1 (2006); 5-121806-25631807-8664reponame:Acta scientiarum. Technology (Online)instname:Universidade Estadual de Maringá (UEM)instacron:UEMporhttp://www.periodicos.uem.br/ojs/index.php/ActaSciTechnol/article/view/1200/712Brinn, Ira MarkRosa, Mauricio Ferreirainfo:eu-repo/semantics/openAccess2024-05-17T13:02:34Zoai:periodicos.uem.br/ojs:article/1200Revistahttps://www.periodicos.uem.br/ojs/index.php/ActaSciTechnol/indexPUBhttps://www.periodicos.uem.br/ojs/index.php/ActaSciTechnol/oai||actatech@uem.br1807-86641806-2563opendoar:2024-05-17T13:02:34Acta scientiarum. Technology (Online) - Universidade Estadual de Maringá (UEM)false
dc.title.none.fl_str_mv Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200
Determinação das constantes de dissociação protônica do 2,7-naftalenodiol no primeiro estado excitado singlete por experimentos com resolução temporal e modelagem matemática - DOI: 10.4025/actascitechnol.v28i1.1200
title Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200
spellingShingle Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200
Brinn, Ira Mark
2
7-naphthanediol
pKa measurements
kinetic modeling
fluorescence decay
2
7-naftalenodiol
medidas de pKa
modelagem cinética
decaimento de fluorescência
1.06.00.00-0 Química
title_short Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200
title_full Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200
title_fullStr Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200
title_full_unstemmed Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200
title_sort Determination of protonic dissociation constants of 2.7-naphthalenediol in the first excited singlet state by experiments with temporal resolution and mathematical modeling - DOI: 10.4025/actascitechnol.v28i1.1200
author Brinn, Ira Mark
author_facet Brinn, Ira Mark
Rosa, Mauricio Ferreira
author_role author
author2 Rosa, Mauricio Ferreira
author2_role author
dc.contributor.author.fl_str_mv Brinn, Ira Mark
Rosa, Mauricio Ferreira
dc.subject.por.fl_str_mv 2
7-naphthanediol
pKa measurements
kinetic modeling
fluorescence decay
2
7-naftalenodiol
medidas de pKa
modelagem cinética
decaimento de fluorescência
1.06.00.00-0 Química
topic 2
7-naphthanediol
pKa measurements
kinetic modeling
fluorescence decay
2
7-naftalenodiol
medidas de pKa
modelagem cinética
decaimento de fluorescência
1.06.00.00-0 Química
description By using the steady-state spectroscopy technique, it was possible to determine the acidity constants of 2.7-naphthalenediol (27ND) in the ground (pKa) and excited states (pKa*). The results of pKa and pKa* obtained, were respectively 9.54 and 6.5. This last value is in poor agreement with the values previously reported. Allying time-correlated single photon counting (TCSPC) experiments and kinetic model calculations made possible to determine, for the first time, the rate constants for the protonic dissociation of 27ND, in the first excited singlet state. The rate constants obtained are: k1 = 1.1x108s-1; k2 = 2.9x108 s-1; k3 = 7.4x108 s-1; kd1 = 8.0x107 M-1s-1; kr1 = 5.0x1010 M-1s-1 and kd2 = 1.0x107 M-1s-1. The acidity constant in the first excited singlet state (pKa*) calculated by the kinetic method (ratio of kd1 and kr1) was 2.8. This value is in best agreement with the ones previously reported in the literature obtained by graphic methods
publishDate 2008
dc.date.none.fl_str_mv 2008-03-20
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://www.periodicos.uem.br/ojs/index.php/ActaSciTechnol/article/view/1200
10.4025/actascitechnol.v28i1.1200
url http://www.periodicos.uem.br/ojs/index.php/ActaSciTechnol/article/view/1200
identifier_str_mv 10.4025/actascitechnol.v28i1.1200
dc.language.iso.fl_str_mv por
language por
dc.relation.none.fl_str_mv http://www.periodicos.uem.br/ojs/index.php/ActaSciTechnol/article/view/1200/712
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universidade Estadual De Maringá
publisher.none.fl_str_mv Universidade Estadual De Maringá
dc.source.none.fl_str_mv Acta Scientiarum. Technology; Vol 28 No 1 (2006); 5-12
Acta Scientiarum. Technology; v. 28 n. 1 (2006); 5-12
1806-2563
1807-8664
reponame:Acta scientiarum. Technology (Online)
instname:Universidade Estadual de Maringá (UEM)
instacron:UEM
instname_str Universidade Estadual de Maringá (UEM)
instacron_str UEM
institution UEM
reponame_str Acta scientiarum. Technology (Online)
collection Acta scientiarum. Technology (Online)
repository.name.fl_str_mv Acta scientiarum. Technology (Online) - Universidade Estadual de Maringá (UEM)
repository.mail.fl_str_mv ||actatech@uem.br
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