Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridil
Autor(a) principal: | |
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Data de Publicação: | 2008 |
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/10316/17950 https://doi.org/10.1016/j.jphotochem.2008.07.005 |
Resumo: | α-Pyridil [(C6H4NO)2] has been isolated in low temperature argon and xenon matrices and studied by FTIR spectroscopy, supported by DFT(B3LYP)/6–311++G(d,p) calculations. Calculations predicted the existence of three different conformers exhibiting skewed conformations around the intercarbonyl bond and the two C5H4NC(O) fragments nearly planar. The two higher energy forms, TCG and CCSk were estimated theoretically to be, respectively, 21.0 and 35.1 kJ mol−1 higher in energy than the most stable form, TTG. In consonance with the relatively high energies predicted by the calculations for the two less stable conformers of α-pyridil, only the most stable conformer was found spectroscopically to be present in the studied matrices. Infrared spectra obtained for the neat low temperature amorphous and crystalline states reveals that the TTG conformer is also the sole conformer present in these phases. UV irradiation (λ > 235 nm) of matrix-isolated α-pyridil led to its isomerization into unusual molecular species bearing Hückel-type pyridine (aza-benzvalene) rings. |
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7160 |
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Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridilα-Pyridil [(C6H4NO)2] has been isolated in low temperature argon and xenon matrices and studied by FTIR spectroscopy, supported by DFT(B3LYP)/6–311++G(d,p) calculations. Calculations predicted the existence of three different conformers exhibiting skewed conformations around the intercarbonyl bond and the two C5H4NC(O) fragments nearly planar. The two higher energy forms, TCG and CCSk were estimated theoretically to be, respectively, 21.0 and 35.1 kJ mol−1 higher in energy than the most stable form, TTG. In consonance with the relatively high energies predicted by the calculations for the two less stable conformers of α-pyridil, only the most stable conformer was found spectroscopically to be present in the studied matrices. Infrared spectra obtained for the neat low temperature amorphous and crystalline states reveals that the TTG conformer is also the sole conformer present in these phases. UV irradiation (λ > 235 nm) of matrix-isolated α-pyridil led to its isomerization into unusual molecular species bearing Hückel-type pyridine (aza-benzvalene) rings.Elsevier2008-07info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/17950http://hdl.handle.net/10316/17950https://doi.org/10.1016/j.jphotochem.2008.07.005engLopes, SusyGómez-Zavaglia, AndreaFausto, 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:10316/17950Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:45.964Repositório 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 |
Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridil |
title |
Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridil |
spellingShingle |
Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridil Lopes, Susy |
title_short |
Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridil |
title_full |
Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridil |
title_fullStr |
Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridil |
title_full_unstemmed |
Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridil |
title_sort |
Low temperature IR spectroscopy and photochemistry of matrix-isolated α-pyridil |
author |
Lopes, Susy |
author_facet |
Lopes, Susy Gómez-Zavaglia, Andrea Fausto, Rui |
author_role |
author |
author2 |
Gómez-Zavaglia, Andrea Fausto, Rui |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Lopes, Susy Gómez-Zavaglia, Andrea Fausto, Rui |
description |
α-Pyridil [(C6H4NO)2] has been isolated in low temperature argon and xenon matrices and studied by FTIR spectroscopy, supported by DFT(B3LYP)/6–311++G(d,p) calculations. Calculations predicted the existence of three different conformers exhibiting skewed conformations around the intercarbonyl bond and the two C5H4NC(O) fragments nearly planar. The two higher energy forms, TCG and CCSk were estimated theoretically to be, respectively, 21.0 and 35.1 kJ mol−1 higher in energy than the most stable form, TTG. In consonance with the relatively high energies predicted by the calculations for the two less stable conformers of α-pyridil, only the most stable conformer was found spectroscopically to be present in the studied matrices. Infrared spectra obtained for the neat low temperature amorphous and crystalline states reveals that the TTG conformer is also the sole conformer present in these phases. UV irradiation (λ > 235 nm) of matrix-isolated α-pyridil led to its isomerization into unusual molecular species bearing Hückel-type pyridine (aza-benzvalene) rings. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008-07 |
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/10316/17950 http://hdl.handle.net/10316/17950 https://doi.org/10.1016/j.jphotochem.2008.07.005 |
url |
http://hdl.handle.net/10316/17950 https://doi.org/10.1016/j.jphotochem.2008.07.005 |
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 |
publisher.none.fl_str_mv |
Elsevier |
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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1799133907966230528 |