Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrate
Autor(a) principal: | |
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Data de Publicação: | 1999 |
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/10316/17727 https://doi.org/10.1007/BF02700694 |
Resumo: | Conformational isomerism in isolated and liquid methyl glycolate and methyl α-hydroxy isobutyrate was investigated by a concerted molecular orbital and vibrational spectroscopic approach (infrared and Raman). The molecular structures, relative energies, dipole moments and vibrational spectra of the various possible conformers of the studied compound were calculated, using the extended 6-31G* basis set at the HF-SCF ab initio level of theory. The theoretical results were then used to interpret infrared and Raman data obtained under different experimental conditions. It was found that both in the liquid and gaseous phase the studied molecules exist in two experimentally observed conformational states, the Cs point group Syn–syn conformer (Ss), which exhibits an intramolecular OH⋯O hydrogen bond, being the most stable form. As expected, the relative populations of the second more stable conformers increase in the liquid phase, since intermolecular interactions tend to reduce the importance of the intramolecular H-bonding that is the main stabilizing factor of the Ss forms. |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrateConformational isomerism in isolated and liquid methyl glycolate and methyl α-hydroxy isobutyrate was investigated by a concerted molecular orbital and vibrational spectroscopic approach (infrared and Raman). The molecular structures, relative energies, dipole moments and vibrational spectra of the various possible conformers of the studied compound were calculated, using the extended 6-31G* basis set at the HF-SCF ab initio level of theory. The theoretical results were then used to interpret infrared and Raman data obtained under different experimental conditions. It was found that both in the liquid and gaseous phase the studied molecules exist in two experimentally observed conformational states, the Cs point group Syn–syn conformer (Ss), which exhibits an intramolecular OH⋯O hydrogen bond, being the most stable form. As expected, the relative populations of the second more stable conformers increase in the liquid phase, since intermolecular interactions tend to reduce the importance of the intramolecular H-bonding that is the main stabilizing factor of the Ss forms.Elsevier Science B.V1999-10info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/17727http://hdl.handle.net/10316/17727https://doi.org/10.1007/BF02700694engJarmelo, S.Fausto, R.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:RCAAP2020-11-06T16:48:40Zoai:estudogeral.uc.pt:10316/17727Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:43.414551Repositório 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 |
Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrate |
title |
Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrate |
spellingShingle |
Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrate Jarmelo, S. |
title_short |
Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrate |
title_full |
Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrate |
title_fullStr |
Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrate |
title_full_unstemmed |
Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrate |
title_sort |
Molecular structure and vibrational spectra of methyl glycolate and methyl α-hydroxy isobutyrate |
author |
Jarmelo, S. |
author_facet |
Jarmelo, S. Fausto, R. |
author_role |
author |
author2 |
Fausto, R. |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Jarmelo, S. Fausto, R. |
description |
Conformational isomerism in isolated and liquid methyl glycolate and methyl α-hydroxy isobutyrate was investigated by a concerted molecular orbital and vibrational spectroscopic approach (infrared and Raman). The molecular structures, relative energies, dipole moments and vibrational spectra of the various possible conformers of the studied compound were calculated, using the extended 6-31G* basis set at the HF-SCF ab initio level of theory. The theoretical results were then used to interpret infrared and Raman data obtained under different experimental conditions. It was found that both in the liquid and gaseous phase the studied molecules exist in two experimentally observed conformational states, the Cs point group Syn–syn conformer (Ss), which exhibits an intramolecular OH⋯O hydrogen bond, being the most stable form. As expected, the relative populations of the second more stable conformers increase in the liquid phase, since intermolecular interactions tend to reduce the importance of the intramolecular H-bonding that is the main stabilizing factor of the Ss forms. |
publishDate |
1999 |
dc.date.none.fl_str_mv |
1999-10 |
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/10316/17727 http://hdl.handle.net/10316/17727 https://doi.org/10.1007/BF02700694 |
url |
http://hdl.handle.net/10316/17727 https://doi.org/10.1007/BF02700694 |
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 |
Elsevier Science B.V |
publisher.none.fl_str_mv |
Elsevier Science B.V |
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 |
|
_version_ |
1799133907877101568 |