Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycine
Autor(a) principal: | |
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Data de Publicação: | 2002 |
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/10316/17807 https://doi.org/10.1039/B207320J |
Resumo: | The structures and vibrational spectra of the preferred conformers of the neutral form of N,N-dimethylglycine (DMG) were studied by a combined approach, using DFT(B3LYP)/6-311++G** and MP2/6-31++G** calculations and low temperature matrix isolation IR spectroscopy. The conformational ground state was found to be the intramolecularly O–HN hydrogen-bonded GAT form, where the (lone pair)-N–C–C and N–C–CO dihedral angles are 30° (gauche; G) and ca. 180° (anti; A), respectively, and the carboxylic group assumes the trans (T) configuration (OC–O–H dihedral angle equal to 180°). The presence in the matrices of two additional conformers, where the carboxylic moiety assumes the most commonly found cis (C) conformation and the N–C–CO axis adopts the syn arrangement (the two conformers differ only in the positions of the methyl groups), could also be established. Observation of these conformers is in consonance with the theoretical predictions, which indicate that the observed conformers should differ in energy by less than 7 kJ mol−1. Full assignment of the observed infrared spectra of both DMG and its -OD isotopomer in Ar and Xe matrices was carried out on the basis of comparison with the theoretically predicted spectra and temperature variation experiments. |
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Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycineThe structures and vibrational spectra of the preferred conformers of the neutral form of N,N-dimethylglycine (DMG) were studied by a combined approach, using DFT(B3LYP)/6-311++G** and MP2/6-31++G** calculations and low temperature matrix isolation IR spectroscopy. The conformational ground state was found to be the intramolecularly O–HN hydrogen-bonded GAT form, where the (lone pair)-N–C–C and N–C–CO dihedral angles are 30° (gauche; G) and ca. 180° (anti; A), respectively, and the carboxylic group assumes the trans (T) configuration (OC–O–H dihedral angle equal to 180°). The presence in the matrices of two additional conformers, where the carboxylic moiety assumes the most commonly found cis (C) conformation and the N–C–CO axis adopts the syn arrangement (the two conformers differ only in the positions of the methyl groups), could also be established. Observation of these conformers is in consonance with the theoretical predictions, which indicate that the observed conformers should differ in energy by less than 7 kJ mol−1. Full assignment of the observed infrared spectra of both DMG and its -OD isotopomer in Ar and Xe matrices was carried out on the basis of comparison with the theoretically predicted spectra and temperature variation experiments.Royal Society of Chemistry2002info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/17807http://hdl.handle.net/10316/17807https://doi.org/10.1039/B207320JengGómez-Zavaglia, A.Reva, I. D.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:RCAAP2022-05-25T01:36:48Zoai:estudogeral.uc.pt:10316/17807Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:44.116118Repositório 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 |
Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycine |
title |
Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycine |
spellingShingle |
Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycine Gómez-Zavaglia, A. |
title_short |
Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycine |
title_full |
Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycine |
title_fullStr |
Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycine |
title_full_unstemmed |
Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycine |
title_sort |
Matrix-isolation FT-IR spectra and molecular orbital calculations on neutral N,N-dimethylglycine |
author |
Gómez-Zavaglia, A. |
author_facet |
Gómez-Zavaglia, A. Reva, I. D. Fausto, R. |
author_role |
author |
author2 |
Reva, I. D. Fausto, R. |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Gómez-Zavaglia, A. Reva, I. D. Fausto, R. |
description |
The structures and vibrational spectra of the preferred conformers of the neutral form of N,N-dimethylglycine (DMG) were studied by a combined approach, using DFT(B3LYP)/6-311++G** and MP2/6-31++G** calculations and low temperature matrix isolation IR spectroscopy. The conformational ground state was found to be the intramolecularly O–HN hydrogen-bonded GAT form, where the (lone pair)-N–C–C and N–C–CO dihedral angles are 30° (gauche; G) and ca. 180° (anti; A), respectively, and the carboxylic group assumes the trans (T) configuration (OC–O–H dihedral angle equal to 180°). The presence in the matrices of two additional conformers, where the carboxylic moiety assumes the most commonly found cis (C) conformation and the N–C–CO axis adopts the syn arrangement (the two conformers differ only in the positions of the methyl groups), could also be established. Observation of these conformers is in consonance with the theoretical predictions, which indicate that the observed conformers should differ in energy by less than 7 kJ mol−1. Full assignment of the observed infrared spectra of both DMG and its -OD isotopomer in Ar and Xe matrices was carried out on the basis of comparison with the theoretically predicted spectra and temperature variation experiments. |
publishDate |
2002 |
dc.date.none.fl_str_mv |
2002 |
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/10316/17807 http://hdl.handle.net/10316/17807 https://doi.org/10.1039/B207320J |
url |
http://hdl.handle.net/10316/17807 https://doi.org/10.1039/B207320J |
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 |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
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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1799133907900170240 |