Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital Study
Autor(a) principal: | |
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Data de Publicação: | 1995 |
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/10316/18102 https://doi.org/10.1039/FT9959101571 |
Resumo: | The results of a combined vibrational and structural study of the acrylic acid monomer undertaken by matrixisolated low-temperature IR spectroscopy and ab initio SCF-HF and MP2 MO calculations are presented. in addition, both Raman and IR spectra of liquid acrylic acid and the Raman spectrum of the crystal are also reported and interpreted. It is shown that in both argon and krypton matrices acrylic acid monomer exists as a mixture of two conformers of similar energies, differing by the relative orientation of the C=C-C=O axis. Upon irradiation at 1 = 243 nm by a xenon lamp, the scis form (C-C-C-0 dihedral angle equal to 0"), corresponding to the conformational ground state, converts to the s-trans form (C=C-C=O dihedral angle equal to 180"). In the liquid phase, dimeric structures strongly predominate, but the existence in this phase of the two conformational states referred to above can also be inferred from the corresponding vibrational spectra. In turn, in the crystal only the thermodynamically most stable form (scis) exists. Results of ab initio SCF-HF and MP2 molecular orbital (MO) calculations, in particular optimised geometries, relative stabilities, dipole moments and harmonic force fields, for the relevant conformational states of acrylic acid are also presented and the conformational dependence of some relevant structural parameters is used to characterise the most important intramolecular interactions present in the studied conformers. Finally, the calculated vibrational spectra and both the results of a normal-mode analysis based on the theoretical harmonic force fields and of IR intensity studies based on the chargecharge flux-overlap (CCFO) model were used to help interpret the experimental vibrational data, enabling a detailed assignment of the acrylic acid spectra obtained in the different conditions considered. |
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Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital StudyThe results of a combined vibrational and structural study of the acrylic acid monomer undertaken by matrixisolated low-temperature IR spectroscopy and ab initio SCF-HF and MP2 MO calculations are presented. in addition, both Raman and IR spectra of liquid acrylic acid and the Raman spectrum of the crystal are also reported and interpreted. It is shown that in both argon and krypton matrices acrylic acid monomer exists as a mixture of two conformers of similar energies, differing by the relative orientation of the C=C-C=O axis. Upon irradiation at 1 = 243 nm by a xenon lamp, the scis form (C-C-C-0 dihedral angle equal to 0"), corresponding to the conformational ground state, converts to the s-trans form (C=C-C=O dihedral angle equal to 180"). In the liquid phase, dimeric structures strongly predominate, but the existence in this phase of the two conformational states referred to above can also be inferred from the corresponding vibrational spectra. In turn, in the crystal only the thermodynamically most stable form (scis) exists. Results of ab initio SCF-HF and MP2 molecular orbital (MO) calculations, in particular optimised geometries, relative stabilities, dipole moments and harmonic force fields, for the relevant conformational states of acrylic acid are also presented and the conformational dependence of some relevant structural parameters is used to characterise the most important intramolecular interactions present in the studied conformers. Finally, the calculated vibrational spectra and both the results of a normal-mode analysis based on the theoretical harmonic force fields and of IR intensity studies based on the chargecharge flux-overlap (CCFO) model were used to help interpret the experimental vibrational data, enabling a detailed assignment of the acrylic acid spectra obtained in the different conditions considered.Royal Society of Chemistry1995info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/18102http://hdl.handle.net/10316/18102https://doi.org/10.1039/FT9959101571engKulbida, AnatolyRamos, Mozart N.Rasanen, MarkkuNieminen, JanneSchrems, OttoFausto, 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:RCAAP2020-11-06T17:00:01Zoai:estudogeral.uc.pt:10316/18102Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:47.680628Repositório 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 |
Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital Study |
title |
Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital Study |
spellingShingle |
Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital Study Kulbida, Anatoly |
title_short |
Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital Study |
title_full |
Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital Study |
title_fullStr |
Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital Study |
title_full_unstemmed |
Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital Study |
title_sort |
Rotational Isomerism in Acrylic Acid: A Combined Matrix-isolated IR, Raman and ab initio Molecular Orbital Study |
author |
Kulbida, Anatoly |
author_facet |
Kulbida, Anatoly Ramos, Mozart N. Rasanen, Markku Nieminen, Janne Schrems, Otto Fausto, Rui |
author_role |
author |
author2 |
Ramos, Mozart N. Rasanen, Markku Nieminen, Janne Schrems, Otto Fausto, Rui |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Kulbida, Anatoly Ramos, Mozart N. Rasanen, Markku Nieminen, Janne Schrems, Otto Fausto, Rui |
description |
The results of a combined vibrational and structural study of the acrylic acid monomer undertaken by matrixisolated low-temperature IR spectroscopy and ab initio SCF-HF and MP2 MO calculations are presented. in addition, both Raman and IR spectra of liquid acrylic acid and the Raman spectrum of the crystal are also reported and interpreted. It is shown that in both argon and krypton matrices acrylic acid monomer exists as a mixture of two conformers of similar energies, differing by the relative orientation of the C=C-C=O axis. Upon irradiation at 1 = 243 nm by a xenon lamp, the scis form (C-C-C-0 dihedral angle equal to 0"), corresponding to the conformational ground state, converts to the s-trans form (C=C-C=O dihedral angle equal to 180"). In the liquid phase, dimeric structures strongly predominate, but the existence in this phase of the two conformational states referred to above can also be inferred from the corresponding vibrational spectra. In turn, in the crystal only the thermodynamically most stable form (scis) exists. Results of ab initio SCF-HF and MP2 molecular orbital (MO) calculations, in particular optimised geometries, relative stabilities, dipole moments and harmonic force fields, for the relevant conformational states of acrylic acid are also presented and the conformational dependence of some relevant structural parameters is used to characterise the most important intramolecular interactions present in the studied conformers. Finally, the calculated vibrational spectra and both the results of a normal-mode analysis based on the theoretical harmonic force fields and of IR intensity studies based on the chargecharge flux-overlap (CCFO) model were used to help interpret the experimental vibrational data, enabling a detailed assignment of the acrylic acid spectra obtained in the different conditions considered. |
publishDate |
1995 |
dc.date.none.fl_str_mv |
1995 |
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/10316/18102 http://hdl.handle.net/10316/18102 https://doi.org/10.1039/FT9959101571 |
url |
http://hdl.handle.net/10316/18102 https://doi.org/10.1039/FT9959101571 |
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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1799133908755808256 |