Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations

Autores
Kaczor, Agnieszka; Gomez Zavaglia, Andrea; Cardoso, Ana Laura; Pinho E Melo, Teresa M. V. D.; Fausto, Rui
Año de publicación
2006
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The aliphatic 2H-azirine, methyl 3-methyl-2H-azirine-2-carboxylate (MMAC), has been synthesized and its monomeric form investigated by IR spectroscopy in an argon matrix, at 10 K, as well as theoretically (DFT/B3LYP/6-311++G(d,p)). Two low-energy conformers of MMAC (Ct and Cc) were found in the matrix, both exhibiting the cis conformation around the C-O bond but differing in the arrangement around the C-C(alpha) bond. The two conformers were photoreactive upon in situ broadband UV excitation (lambda > 235 nm), yielding nitrile ylide (P1) and ketene imine (P2) type products, which resulted from cleavage of the C-C or C-N bond, respectively. The kinetics of the reactions leading to the formation of P1 and P2 are of first order, with the processes being favored when the reactant is in the Cc conformation. Very interestingly, the C-N bond photocleavage, which is unusual for aliphatic 2H-azirines, was found to be preferred over the generally favored in 2H-azirines C-C bond breakage. This behavior is attributed to the presence in the molecule of the electron-withdrawing methoxycarbonyl substituent, which accelerates the intersystem crossing toward the T(1) triplet state and, in this way, favors the C-N bond cleavage. In addition to the primary photoprocesses leading to formation of P1 and P2, secondary photoprocesses leading to the decarboxylation and decarbonylation of P2 have been also observed.
Fil: Kaczor, Agnieszka. Universidad de Coimbra; Portugal. Jagiellonian University; Polonia
Fil: Gomez Zavaglia, Andrea. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Universidad de Coimbra; Portugal. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina
Fil: Cardoso, Ana Laura. Universidad de Coimbra; Portugal
Fil: Pinho E Melo, Teresa M. V. D.. Universidad de Coimbra; Portugal
Fil: Fausto, Rui. Universidad de Coimbra; Portugal
Materia
FTIR
photochemistry
matrix isolation
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/115295
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/115295
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculationsKaczor, AgnieszkaGomez Zavaglia, AndreaCardoso, Ana LauraPinho E Melo, Teresa M. V. D.Fausto, RuiFTIRphotochemistrymatrix isolationhttps://purl.org/becyt/ford/2.11https://purl.org/becyt/ford/2The aliphatic 2H-azirine, methyl 3-methyl-2H-azirine-2-carboxylate (MMAC), has been synthesized and its monomeric form investigated by IR spectroscopy in an argon matrix, at 10 K, as well as theoretically (DFT/B3LYP/6-311++G(d,p)). Two low-energy conformers of MMAC (Ct and Cc) were found in the matrix, both exhibiting the cis conformation around the C-O bond but differing in the arrangement around the C-C(alpha) bond. The two conformers were photoreactive upon in situ broadband UV excitation (lambda > 235 nm), yielding nitrile ylide (P1) and ketene imine (P2) type products, which resulted from cleavage of the C-C or C-N bond, respectively. The kinetics of the reactions leading to the formation of P1 and P2 are of first order, with the processes being favored when the reactant is in the Cc conformation. Very interestingly, the C-N bond photocleavage, which is unusual for aliphatic 2H-azirines, was found to be preferred over the generally favored in 2H-azirines C-C bond breakage. This behavior is attributed to the presence in the molecule of the electron-withdrawing methoxycarbonyl substituent, which accelerates the intersystem crossing toward the T(1) triplet state and, in this way, favors the C-N bond cleavage. In addition to the primary photoprocesses leading to formation of P1 and P2, secondary photoprocesses leading to the decarboxylation and decarbonylation of P2 have been also observed.Fil: Kaczor, Agnieszka. Universidad de Coimbra; Portugal. Jagiellonian University; PoloniaFil: Gomez Zavaglia, Andrea. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Universidad de Coimbra; Portugal. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Cardoso, Ana Laura. Universidad de Coimbra; PortugalFil: Pinho E Melo, Teresa M. V. D.. Universidad de Coimbra; PortugalFil: Fausto, Rui. Universidad de Coimbra; PortugalAmerican Chemical Society2006-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/115295Kaczor, Agnieszka; Gomez Zavaglia, Andrea; Cardoso, Ana Laura; Pinho E Melo, Teresa M. V. D.; Fausto, Rui; Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations; American Chemical Society; Journal of Physical Chemistry A; 110; 37; 8-2006; 10742-107491089-5639CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1021/jp064049oinfo:eu-repo/semantics/altIdentifier/url/https://tinyurl.com/y6xjfnhoinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:47:08Zoai:ri.conicet.gov.ar:11336/115295instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 09:47:08.648CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations
title Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations
spellingShingle Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations
Kaczor, Agnieszka
FTIR
photochemistry
matrix isolation
title_short Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations
title_full Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations
title_fullStr Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations
title_full_unstemmed Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations
title_sort Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations
dc.creator.none.fl_str_mv Kaczor, Agnieszka
Gomez Zavaglia, Andrea
Cardoso, Ana Laura
Pinho E Melo, Teresa M. V. D.
Fausto, Rui
author Kaczor, Agnieszka
author_facet Kaczor, Agnieszka
Gomez Zavaglia, Andrea
Cardoso, Ana Laura
Pinho E Melo, Teresa M. V. D.
Fausto, Rui
author_role author
author2 Gomez Zavaglia, Andrea
Cardoso, Ana Laura
Pinho E Melo, Teresa M. V. D.
Fausto, Rui
author2_role author
author
author
author
dc.subject.none.fl_str_mv FTIR
photochemistry
matrix isolation
topic FTIR
photochemistry
matrix isolation
purl_subject.fl_str_mv https://purl.org/becyt/ford/2.11
https://purl.org/becyt/ford/2
dc.description.none.fl_txt_mv The aliphatic 2H-azirine, methyl 3-methyl-2H-azirine-2-carboxylate (MMAC), has been synthesized and its monomeric form investigated by IR spectroscopy in an argon matrix, at 10 K, as well as theoretically (DFT/B3LYP/6-311++G(d,p)). Two low-energy conformers of MMAC (Ct and Cc) were found in the matrix, both exhibiting the cis conformation around the C-O bond but differing in the arrangement around the C-C(alpha) bond. The two conformers were photoreactive upon in situ broadband UV excitation (lambda > 235 nm), yielding nitrile ylide (P1) and ketene imine (P2) type products, which resulted from cleavage of the C-C or C-N bond, respectively. The kinetics of the reactions leading to the formation of P1 and P2 are of first order, with the processes being favored when the reactant is in the Cc conformation. Very interestingly, the C-N bond photocleavage, which is unusual for aliphatic 2H-azirines, was found to be preferred over the generally favored in 2H-azirines C-C bond breakage. This behavior is attributed to the presence in the molecule of the electron-withdrawing methoxycarbonyl substituent, which accelerates the intersystem crossing toward the T(1) triplet state and, in this way, favors the C-N bond cleavage. In addition to the primary photoprocesses leading to formation of P1 and P2, secondary photoprocesses leading to the decarboxylation and decarbonylation of P2 have been also observed.
Fil: Kaczor, Agnieszka. Universidad de Coimbra; Portugal. Jagiellonian University; Polonia
Fil: Gomez Zavaglia, Andrea. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Universidad de Coimbra; Portugal. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina
Fil: Cardoso, Ana Laura. Universidad de Coimbra; Portugal
Fil: Pinho E Melo, Teresa M. V. D.. Universidad de Coimbra; Portugal
Fil: Fausto, Rui. Universidad de Coimbra; Portugal
description The aliphatic 2H-azirine, methyl 3-methyl-2H-azirine-2-carboxylate (MMAC), has been synthesized and its monomeric form investigated by IR spectroscopy in an argon matrix, at 10 K, as well as theoretically (DFT/B3LYP/6-311++G(d,p)). Two low-energy conformers of MMAC (Ct and Cc) were found in the matrix, both exhibiting the cis conformation around the C-O bond but differing in the arrangement around the C-C(alpha) bond. The two conformers were photoreactive upon in situ broadband UV excitation (lambda > 235 nm), yielding nitrile ylide (P1) and ketene imine (P2) type products, which resulted from cleavage of the C-C or C-N bond, respectively. The kinetics of the reactions leading to the formation of P1 and P2 are of first order, with the processes being favored when the reactant is in the Cc conformation. Very interestingly, the C-N bond photocleavage, which is unusual for aliphatic 2H-azirines, was found to be preferred over the generally favored in 2H-azirines C-C bond breakage. This behavior is attributed to the presence in the molecule of the electron-withdrawing methoxycarbonyl substituent, which accelerates the intersystem crossing toward the T(1) triplet state and, in this way, favors the C-N bond cleavage. In addition to the primary photoprocesses leading to formation of P1 and P2, secondary photoprocesses leading to the decarboxylation and decarbonylation of P2 have been also observed.
publishDate 2006
dc.date.none.fl_str_mv 2006-08
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/115295
Kaczor, Agnieszka; Gomez Zavaglia, Andrea; Cardoso, Ana Laura; Pinho E Melo, Teresa M. V. D.; Fausto, Rui; Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations; American Chemical Society; Journal of Physical Chemistry A; 110; 37; 8-2006; 10742-10749
1089-5639
CONICET Digital
CONICET
url http://hdl.handle.net/11336/115295
identifier_str_mv Kaczor, Agnieszka; Gomez Zavaglia, Andrea; Cardoso, Ana Laura; Pinho E Melo, Teresa M. V. D.; Fausto, Rui; Methyl 3-methyl-2H-azirine-2-carboxylate photochemistry studied by matrix-isolation FTIR and DFT calculations; American Chemical Society; Journal of Physical Chemistry A; 110; 37; 8-2006; 10742-10749
1089-5639
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1021/jp064049o
info:eu-repo/semantics/altIdentifier/url/https://tinyurl.com/y6xjfnho
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Chemical Society
publisher.none.fl_str_mv American Chemical Society
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.13397

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