s-cis and s-trans Conformers of Formic, Thioformic and
Autor(a) principal: | |
---|---|
Data de Publicação: | 1989 |
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/10316/18088 https://doi.org/10.1039/F29898501945 |
Resumo: | Ab initio SCF-MO calculations have been carried out for formic, thioformic and dithioformic acids using the 6-31G* basis set. Fully optimized geometries, atomic charges, relative stabilities and harmonic force fields for s-cis and s-trans conformers of these molecules have been determined and the effects of oxygen-by-sulphur substitution analysed. A realistic description of the molecular charge distribution can be reached by introducing a quantum-mechanical correction to the Mulliken atomic charges, derived from the 'charge'-'charge flux'-'overlap' (CCFO) model. Unlike reported theoretical results, the present ab initio calculations yield relative stabilities of the thioformic acid conformers in agreement with experiment [s-cis (thiol) > s-trans(thio1) > s-cis(thione) > s-trans(thione)]. The success of these ab initio calculations should be partially ascribed to the inclusion of polarization functions on all non-hydrogen atoms. |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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7160 |
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s-cis and s-trans Conformers of Formic, Thioformic andAb initio SCF-MO calculations have been carried out for formic, thioformic and dithioformic acids using the 6-31G* basis set. Fully optimized geometries, atomic charges, relative stabilities and harmonic force fields for s-cis and s-trans conformers of these molecules have been determined and the effects of oxygen-by-sulphur substitution analysed. A realistic description of the molecular charge distribution can be reached by introducing a quantum-mechanical correction to the Mulliken atomic charges, derived from the 'charge'-'charge flux'-'overlap' (CCFO) model. Unlike reported theoretical results, the present ab initio calculations yield relative stabilities of the thioformic acid conformers in agreement with experiment [s-cis (thiol) > s-trans(thio1) > s-cis(thione) > s-trans(thione)]. The success of these ab initio calculations should be partially ascribed to the inclusion of polarization functions on all non-hydrogen atoms.Royal Society of Chemistry1989info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/18088http://hdl.handle.net/10316/18088https://doi.org/10.1039/F29898501945engFausto, R.Carvalho, L. A. E. Batista deTeixeira-Dias, J. J. C.Ramos, M. N.info: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:RCAAP2021-07-26T11:14:29Zoai:estudogeral.uc.pt:10316/18088Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:47.469986Repositório 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 |
s-cis and s-trans Conformers of Formic, Thioformic and |
title |
s-cis and s-trans Conformers of Formic, Thioformic and |
spellingShingle |
s-cis and s-trans Conformers of Formic, Thioformic and Fausto, R. |
title_short |
s-cis and s-trans Conformers of Formic, Thioformic and |
title_full |
s-cis and s-trans Conformers of Formic, Thioformic and |
title_fullStr |
s-cis and s-trans Conformers of Formic, Thioformic and |
title_full_unstemmed |
s-cis and s-trans Conformers of Formic, Thioformic and |
title_sort |
s-cis and s-trans Conformers of Formic, Thioformic and |
author |
Fausto, R. |
author_facet |
Fausto, R. Carvalho, L. A. E. Batista de Teixeira-Dias, J. J. C. Ramos, M. N. |
author_role |
author |
author2 |
Carvalho, L. A. E. Batista de Teixeira-Dias, J. J. C. Ramos, M. N. |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Fausto, R. Carvalho, L. A. E. Batista de Teixeira-Dias, J. J. C. Ramos, M. N. |
description |
Ab initio SCF-MO calculations have been carried out for formic, thioformic and dithioformic acids using the 6-31G* basis set. Fully optimized geometries, atomic charges, relative stabilities and harmonic force fields for s-cis and s-trans conformers of these molecules have been determined and the effects of oxygen-by-sulphur substitution analysed. A realistic description of the molecular charge distribution can be reached by introducing a quantum-mechanical correction to the Mulliken atomic charges, derived from the 'charge'-'charge flux'-'overlap' (CCFO) model. Unlike reported theoretical results, the present ab initio calculations yield relative stabilities of the thioformic acid conformers in agreement with experiment [s-cis (thiol) > s-trans(thio1) > s-cis(thione) > s-trans(thione)]. The success of these ab initio calculations should be partially ascribed to the inclusion of polarization functions on all non-hydrogen atoms. |
publishDate |
1989 |
dc.date.none.fl_str_mv |
1989 |
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/10316/18088 http://hdl.handle.net/10316/18088 https://doi.org/10.1039/F29898501945 |
url |
http://hdl.handle.net/10316/18088 https://doi.org/10.1039/F29898501945 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Royal Society of Chemistry |
publisher.none.fl_str_mv |
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 |
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 |
repository.mail.fl_str_mv |
|
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1799133908748468224 |