Combined experimental and computational study of the thermochemistry of methylpiperidines
Autor(a) principal: | |
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Data de Publicação: | 2006 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | https://repositorio-aberto.up.pt/handle/10216/82044 |
Resumo: | To understand the influence of the methyl group in the stability and conformational behavior of the piperidine ring, the standard (p(0) = 0.1 MPa) molar enthalpies of formation of 1-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 2,6-dimethylpiperidine, and 3,5-dimethylpiperidine, both in the liquid and in the gaseous states, were determined at the temperature of 298.15 K. The numerical values of the enthalpies of formation in the liquid and in the gaseous state are, respectively, -(95.9 +/- 1.6) and -(59.1 +/- 1.7) kJ, mol(-1) for 1-methylpiperidine; -(123.6 +/- 1.4) and -(79.2 +/- 1.6) kJ, mol(-1) for 3-methylpiperidine; -(123.5 +/- 1.5) and -(82.9 +/- 1.7) kJ, mol(-1) for 4-methylpiperidine; -(153.6 +/- 2.1) and -(111.2 +/- 2.2) kJ, mol(-1) for 2,6-dimethylpiperidine; and -(155.0 +/- 1.7) and -(105.9 +/- 1.8) kJ, mol(-1) for 3,5-dimethylpiperidine. In addition, and to be compared with the experimental results, theoretical calculations were carried out considering different ab initio and density functional theory based methods. The standard molar enthalpies of formation of the four isomers of methylpiperidine and of the 12 isomers of dimethylpiperidine have been computed. The G3MP2B3-derived numbers are in excellent agreement with experimental data, except in the case of 2,6-dimethylpiperidine for which a deviation of 9 kJ (.) mol(-1) was found. Surprisingly, the DFT methods fail in the prediction of these properties with the exception of the most approximated SVWN functional. |
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Combined experimental and computational study of the thermochemistry of methylpiperidinesQuímicaChemical sciencesTo understand the influence of the methyl group in the stability and conformational behavior of the piperidine ring, the standard (p(0) = 0.1 MPa) molar enthalpies of formation of 1-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 2,6-dimethylpiperidine, and 3,5-dimethylpiperidine, both in the liquid and in the gaseous states, were determined at the temperature of 298.15 K. The numerical values of the enthalpies of formation in the liquid and in the gaseous state are, respectively, -(95.9 +/- 1.6) and -(59.1 +/- 1.7) kJ, mol(-1) for 1-methylpiperidine; -(123.6 +/- 1.4) and -(79.2 +/- 1.6) kJ, mol(-1) for 3-methylpiperidine; -(123.5 +/- 1.5) and -(82.9 +/- 1.7) kJ, mol(-1) for 4-methylpiperidine; -(153.6 +/- 2.1) and -(111.2 +/- 2.2) kJ, mol(-1) for 2,6-dimethylpiperidine; and -(155.0 +/- 1.7) and -(105.9 +/- 1.8) kJ, mol(-1) for 3,5-dimethylpiperidine. In addition, and to be compared with the experimental results, theoretical calculations were carried out considering different ab initio and density functional theory based methods. The standard molar enthalpies of formation of the four isomers of methylpiperidine and of the 12 isomers of dimethylpiperidine have been computed. The G3MP2B3-derived numbers are in excellent agreement with experimental data, except in the case of 2,6-dimethylpiperidine for which a deviation of 9 kJ (.) mol(-1) was found. Surprisingly, the DFT methods fail in the prediction of these properties with the exception of the most approximated SVWN functional.20062006-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttps://repositorio-aberto.up.pt/handle/10216/82044eng0022-326310.1021/jo052468wda Silva, MAVRCabral, JITAGomes, PGomes, JRBinfo: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:RCAAP2023-11-29T12:58:36Zoai:repositorio-aberto.up.pt:10216/82044Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T23:30:48.787838Repositório 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 |
Combined experimental and computational study of the thermochemistry of methylpiperidines |
title |
Combined experimental and computational study of the thermochemistry of methylpiperidines |
spellingShingle |
Combined experimental and computational study of the thermochemistry of methylpiperidines da Silva, MAVR Química Chemical sciences |
title_short |
Combined experimental and computational study of the thermochemistry of methylpiperidines |
title_full |
Combined experimental and computational study of the thermochemistry of methylpiperidines |
title_fullStr |
Combined experimental and computational study of the thermochemistry of methylpiperidines |
title_full_unstemmed |
Combined experimental and computational study of the thermochemistry of methylpiperidines |
title_sort |
Combined experimental and computational study of the thermochemistry of methylpiperidines |
author |
da Silva, MAVR |
author_facet |
da Silva, MAVR Cabral, JITA Gomes, P Gomes, JRB |
author_role |
author |
author2 |
Cabral, JITA Gomes, P Gomes, JRB |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
da Silva, MAVR Cabral, JITA Gomes, P Gomes, JRB |
dc.subject.por.fl_str_mv |
Química Chemical sciences |
topic |
Química Chemical sciences |
description |
To understand the influence of the methyl group in the stability and conformational behavior of the piperidine ring, the standard (p(0) = 0.1 MPa) molar enthalpies of formation of 1-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 2,6-dimethylpiperidine, and 3,5-dimethylpiperidine, both in the liquid and in the gaseous states, were determined at the temperature of 298.15 K. The numerical values of the enthalpies of formation in the liquid and in the gaseous state are, respectively, -(95.9 +/- 1.6) and -(59.1 +/- 1.7) kJ, mol(-1) for 1-methylpiperidine; -(123.6 +/- 1.4) and -(79.2 +/- 1.6) kJ, mol(-1) for 3-methylpiperidine; -(123.5 +/- 1.5) and -(82.9 +/- 1.7) kJ, mol(-1) for 4-methylpiperidine; -(153.6 +/- 2.1) and -(111.2 +/- 2.2) kJ, mol(-1) for 2,6-dimethylpiperidine; and -(155.0 +/- 1.7) and -(105.9 +/- 1.8) kJ, mol(-1) for 3,5-dimethylpiperidine. In addition, and to be compared with the experimental results, theoretical calculations were carried out considering different ab initio and density functional theory based methods. The standard molar enthalpies of formation of the four isomers of methylpiperidine and of the 12 isomers of dimethylpiperidine have been computed. The G3MP2B3-derived numbers are in excellent agreement with experimental data, except in the case of 2,6-dimethylpiperidine for which a deviation of 9 kJ (.) mol(-1) was found. Surprisingly, the DFT methods fail in the prediction of these properties with the exception of the most approximated SVWN functional. |
publishDate |
2006 |
dc.date.none.fl_str_mv |
2006 2006-01-01T00:00:00Z |
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 |
https://repositorio-aberto.up.pt/handle/10216/82044 |
url |
https://repositorio-aberto.up.pt/handle/10216/82044 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
0022-3263 10.1021/jo052468w |
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.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 |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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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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1799135616875626496 |