Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite
Autor(a) principal: | |
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Data de Publicação: | 2005 |
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/10316/12879 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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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) 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 |
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