Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite

Detalhes bibliográficos
Autor(a) principal: Borba, Ana
Data de Publicação: 2005
Outros Autores: Gómez-Zavaglia, Andrea, Simões, Pedro N. N. L., Fausto, Rui
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10316/12879
https://doi.org/10.1016/j.vibspec.2004.03.004
Resumo: The preferred conformations of dimethyl sulfite and their vibrational spectra were studied by matrix-isolation Fourier transform infrared spectroscopy and theoretical methods (density functional theory (DFT) and MollerPlesset (MP2), with basis sets of different sizes, including the quadruple-zeta, aug-cc-pVQZ basis). Five minima were found at these levels of theory. At the MP2/6-31++G(d,p) and DFT/B3LYP/aug-cc-pVQPZ levels, the GG conformer (where the OSOC dihedral angles are 73.2 and 70.8o) resulted in the conformational ground state. At the highest level of theory used, the GT conformer (OSOC = +68.5 and 173.2o) is 0.83 kJ mol-1 higher in energy than the GG form, while conformer GG` (OSOC = +85.7 and 85.7o) has a relative energy of 1.18 kJ mol-1. The remaining two conformers (G`T and TT) are high-energy forms and not experimentally relevant. In consonance with the theoretical predictions, conformer GG was found to be the most stable conformer in the gaseous phase as well as in the low-temperature matrices. Annealing of the argon matrices first promotes the GG`GT isomerization, which is followed by conversion of GT into the most stable conformer. There is no evidence of occurrence of GG`GG direct conversion in the low-temperature matrices. On the other hand, during deposition of the xenon matrices conformer GG` totally converts to conformer GT. Two observations demonstrated this fact: no evidence of bands corresponding to GG` were observed in xenon matrices and the GG/GT intensity ratio became similar to the GG/(GT + GG`) intensity ratio observed in argon matrices. All these results could be explained by taking into account the relative values of the theoretically predicted energy barriers for the different isomerization processes: GG`GT, 1.90 kJ mol-1; GTGG, 9.64 kJ mol-1; and GG`GG, 19.46 kJ mol-1
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spelling Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl SulfiteThe preferred conformations of dimethyl sulfite and their vibrational spectra were studied by matrix-isolation Fourier transform infrared spectroscopy and theoretical methods (density functional theory (DFT) and MollerPlesset (MP2), with basis sets of different sizes, including the quadruple-zeta, aug-cc-pVQZ basis). Five minima were found at these levels of theory. At the MP2/6-31++G(d,p) and DFT/B3LYP/aug-cc-pVQPZ levels, the GG conformer (where the OSOC dihedral angles are 73.2 and 70.8o) resulted in the conformational ground state. At the highest level of theory used, the GT conformer (OSOC = +68.5 and 173.2o) is 0.83 kJ mol-1 higher in energy than the GG form, while conformer GG` (OSOC = +85.7 and 85.7o) has a relative energy of 1.18 kJ mol-1. The remaining two conformers (G`T and TT) are high-energy forms and not experimentally relevant. In consonance with the theoretical predictions, conformer GG was found to be the most stable conformer in the gaseous phase as well as in the low-temperature matrices. Annealing of the argon matrices first promotes the GG`GT isomerization, which is followed by conversion of GT into the most stable conformer. There is no evidence of occurrence of GG`GG direct conversion in the low-temperature matrices. On the other hand, during deposition of the xenon matrices conformer GG` totally converts to conformer GT. Two observations demonstrated this fact: no evidence of bands corresponding to GG` were observed in xenon matrices and the GG/GT intensity ratio became similar to the GG/(GT + GG`) intensity ratio observed in argon matrices. All these results could be explained by taking into account the relative values of the theoretically predicted energy barriers for the different isomerization processes: GG`GT, 1.90 kJ mol-1; GTGG, 9.64 kJ mol-1; and GG`GG, 19.46 kJ mol-1American Chemical Society2005-04-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/12879http://hdl.handle.net/10316/12879https://doi.org/10.1016/j.vibspec.2004.03.004engThe Journal of Physical Chemistry A. 109:16 (2005) 3578-35861089-5639Borba, AnaGómez-Zavaglia, AndreaSimões, Pedro N. N. L.Fausto, Ruiinfo: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:RCAAP2021-09-03T10:14:00Zoai:estudogeral.uc.pt:10316/12879Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:41.552693Repositório 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 FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite
title Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite
spellingShingle Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite
Borba, Ana
title_short Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite
title_full Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite
title_fullStr Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite
title_full_unstemmed Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite
title_sort Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite
author Borba, Ana
author_facet Borba, Ana
Gómez-Zavaglia, Andrea
Simões, Pedro N. N. L.
Fausto, Rui
author_role author
author2 Gómez-Zavaglia, Andrea
Simões, Pedro N. N. L.
Fausto, Rui
author2_role author
author
author
dc.contributor.author.fl_str_mv Borba, Ana
Gómez-Zavaglia, Andrea
Simões, Pedro N. N. L.
Fausto, Rui
description The preferred conformations of dimethyl sulfite and their vibrational spectra were studied by matrix-isolation Fourier transform infrared spectroscopy and theoretical methods (density functional theory (DFT) and MollerPlesset (MP2), with basis sets of different sizes, including the quadruple-zeta, aug-cc-pVQZ basis). Five minima were found at these levels of theory. At the MP2/6-31++G(d,p) and DFT/B3LYP/aug-cc-pVQPZ levels, the GG conformer (where the OSOC dihedral angles are 73.2 and 70.8o) resulted in the conformational ground state. At the highest level of theory used, the GT conformer (OSOC = +68.5 and 173.2o) is 0.83 kJ mol-1 higher in energy than the GG form, while conformer GG` (OSOC = +85.7 and 85.7o) has a relative energy of 1.18 kJ mol-1. The remaining two conformers (G`T and TT) are high-energy forms and not experimentally relevant. In consonance with the theoretical predictions, conformer GG was found to be the most stable conformer in the gaseous phase as well as in the low-temperature matrices. Annealing of the argon matrices first promotes the GG`GT isomerization, which is followed by conversion of GT into the most stable conformer. There is no evidence of occurrence of GG`GG direct conversion in the low-temperature matrices. On the other hand, during deposition of the xenon matrices conformer GG` totally converts to conformer GT. Two observations demonstrated this fact: no evidence of bands corresponding to GG` were observed in xenon matrices and the GG/GT intensity ratio became similar to the GG/(GT + GG`) intensity ratio observed in argon matrices. All these results could be explained by taking into account the relative values of the theoretically predicted energy barriers for the different isomerization processes: GG`GT, 1.90 kJ mol-1; GTGG, 9.64 kJ mol-1; and GG`GG, 19.46 kJ mol-1
publishDate 2005
dc.date.none.fl_str_mv 2005-04-01
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/10316/12879
http://hdl.handle.net/10316/12879
https://doi.org/10.1016/j.vibspec.2004.03.004
url http://hdl.handle.net/10316/12879
https://doi.org/10.1016/j.vibspec.2004.03.004
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv The Journal of Physical Chemistry A. 109:16 (2005) 3578-3586
1089-5639
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv American Chemical Society
publisher.none.fl_str_mv American Chemical Society
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
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instacron_str RCAAP
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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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