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
Autor(a) principal: | |
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Data de Publicação: | 2008 |
Outros Autores: | |
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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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 |
_version_ |
1799315331547660288 |