Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide
Autor(a) principal: | |
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Data de Publicação: | 2008 |
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/10400.1/3226 |
Resumo: | The reaction kinetics for the acid nitrosation of formamidine disulfide (FDS) show an autocatalytic behavior that arises from the fact that the thiocyanate ion formed as a product acts as a powerful catalyst for the nitrosation reaction. In the presence of added nucleophiles the suppression of the autocatalytic route results from competition for the nitrous acid between the added halides and the thiocyanate anion, which is formed as a reaction product. Analysis of the kinetic data enabled extraction of the bimolecular rate constants, kNO+ = (3.2 1.8) 1010 M 1 s 1; kNOSCN = (2.1 0.2) 105 M 1 s 1; kNOBr = (9.4 0.2) 106 M 1 s1 and kNOCl = (4.0 0.2) 107 M 1 s 1, for the pathways catalyzed by SCN , Br and Cl , respectively. Kinetic results are consistent with the attack on the nitrosating agent as the rate limiting step, i.e., the nitrosation of FDS behaves in a similar manner to the nitrosation of an amine. Rather different behavior is found for other substrates with an imino moiety adjacent to an amino nitrogen, such as the guanidines, which react by a mechanism in which the rate limiting step is the reorganization of the nitrosated substrate. |
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Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfideThe reaction kinetics for the acid nitrosation of formamidine disulfide (FDS) show an autocatalytic behavior that arises from the fact that the thiocyanate ion formed as a product acts as a powerful catalyst for the nitrosation reaction. In the presence of added nucleophiles the suppression of the autocatalytic route results from competition for the nitrous acid between the added halides and the thiocyanate anion, which is formed as a reaction product. Analysis of the kinetic data enabled extraction of the bimolecular rate constants, kNO+ = (3.2 1.8) 1010 M 1 s 1; kNOSCN = (2.1 0.2) 105 M 1 s 1; kNOBr = (9.4 0.2) 106 M 1 s1 and kNOCl = (4.0 0.2) 107 M 1 s 1, for the pathways catalyzed by SCN , Br and Cl , respectively. Kinetic results are consistent with the attack on the nitrosating agent as the rate limiting step, i.e., the nitrosation of FDS behaves in a similar manner to the nitrosation of an amine. Rather different behavior is found for other substrates with an imino moiety adjacent to an amino nitrogen, such as the guanidines, which react by a mechanism in which the rate limiting step is the reorganization of the nitrosated substrate.RSC Publishing - Royal Society of ChemistrySapientiaFrancisco, VitorGarcía-Río, LuísMoreira, JoséStedman, Geoffrey2013-12-06T15:03:52Z20082013-12-04T18:15:45Z2008-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.1/3226engFrancisco, Vitor; García-Río, Luís; Moreira, José A.; Stedman, Geoffrey. Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide, New Journal of Chemistry, 32, 12, 2292-2292, 2008.1144-0546AUT: JMO01545;http://dx.doi.org/0.1039/b810761kinfo: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:RCAAP2023-07-24T10:14:15Zoai:sapientia.ualg.pt:10400.1/3226Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:56:50.702646Repositório 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 |
Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide |
title |
Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide |
spellingShingle |
Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide Francisco, Vitor |
title_short |
Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide |
title_full |
Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide |
title_fullStr |
Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide |
title_full_unstemmed |
Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide |
title_sort |
Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide |
author |
Francisco, Vitor |
author_facet |
Francisco, Vitor García-Río, Luís Moreira, José Stedman, Geoffrey |
author_role |
author |
author2 |
García-Río, Luís Moreira, José Stedman, Geoffrey |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Sapientia |
dc.contributor.author.fl_str_mv |
Francisco, Vitor García-Río, Luís Moreira, José Stedman, Geoffrey |
description |
The reaction kinetics for the acid nitrosation of formamidine disulfide (FDS) show an autocatalytic behavior that arises from the fact that the thiocyanate ion formed as a product acts as a powerful catalyst for the nitrosation reaction. In the presence of added nucleophiles the suppression of the autocatalytic route results from competition for the nitrous acid between the added halides and the thiocyanate anion, which is formed as a reaction product. Analysis of the kinetic data enabled extraction of the bimolecular rate constants, kNO+ = (3.2 1.8) 1010 M 1 s 1; kNOSCN = (2.1 0.2) 105 M 1 s 1; kNOBr = (9.4 0.2) 106 M 1 s1 and kNOCl = (4.0 0.2) 107 M 1 s 1, for the pathways catalyzed by SCN , Br and Cl , respectively. Kinetic results are consistent with the attack on the nitrosating agent as the rate limiting step, i.e., the nitrosation of FDS behaves in a similar manner to the nitrosation of an amine. Rather different behavior is found for other substrates with an imino moiety adjacent to an amino nitrogen, such as the guanidines, which react by a mechanism in which the rate limiting step is the reorganization of the nitrosated substrate. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008 2008-01-01T00:00:00Z 2013-12-06T15:03:52Z 2013-12-04T18:15:45Z |
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/10400.1/3226 |
url |
http://hdl.handle.net/10400.1/3226 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Francisco, Vitor; García-Río, Luís; Moreira, José A.; Stedman, Geoffrey. Kinetic study of an autocatalytic reaction: nitrosation of formamidine disulfide, New Journal of Chemistry, 32, 12, 2292-2292, 2008. 1144-0546 AUT: JMO01545; http://dx.doi.org/0.1039/b810761k |
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 |
RSC Publishing - Royal Society of Chemistry |
publisher.none.fl_str_mv |
RSC Publishing - Royal Society of Chemistry |
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 |
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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1799133177933987840 |