Dipolar repulsion in α-halocarbonyl compounds revisited
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFLA |
Texto Completo: | http://repositorio.ufla.br/jspui/handle/1/48796 |
Resumo: | The concept of dipolar repulsion has been widely used to explain several phenomena in organic chemistry, including the conformational preferences of carbonyl compounds. This model, in which atoms and bonds are viewed as point charges and dipole moment vectors, respectively, is however oversimplified. To provide a causal model rooted in quantitative molecular orbital theory, we have analyzed the rotational isomerism of haloacetaldehydes OHC–CH2X (X = F, Cl, Br, I), using relativistic density functional theory. We have found that the overall trend in the rotational energy profiles is set by the combined effects of Pauli repulsion (introducing a barrier around gauche that separates minima at syn and anti), orbital interactions (which can pull the anti minimum towards anticlinal to maximize hyperconjugation), and electrostatic interactions. Only for X = F, not for X = Cl–I, electrostatic interactions push the preference from syn to anti. Our bonding analyses show how this trend is related to the compact nature of F versus the more diffuse nature of the heavier halogens. |
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Dipolar repulsion in α-halocarbonyl compounds revisitedRotational energy profilesOrbital interactionsElectrostatic interactionsThe concept of dipolar repulsion has been widely used to explain several phenomena in organic chemistry, including the conformational preferences of carbonyl compounds. This model, in which atoms and bonds are viewed as point charges and dipole moment vectors, respectively, is however oversimplified. To provide a causal model rooted in quantitative molecular orbital theory, we have analyzed the rotational isomerism of haloacetaldehydes OHC–CH2X (X = F, Cl, Br, I), using relativistic density functional theory. We have found that the overall trend in the rotational energy profiles is set by the combined effects of Pauli repulsion (introducing a barrier around gauche that separates minima at syn and anti), orbital interactions (which can pull the anti minimum towards anticlinal to maximize hyperconjugation), and electrostatic interactions. Only for X = F, not for X = Cl–I, electrostatic interactions push the preference from syn to anti. Our bonding analyses show how this trend is related to the compact nature of F versus the more diffuse nature of the heavier halogens.Royal Society of Chemistry2022-01-06T15:46:08Z2022-01-06T15:46:08Z2021-09-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfSILVA, D. R. et al. Dipolar repulsion in α-halocarbonyl compounds revisited. Physical Chemistry Chemical Physics, [S.l.], v. 23, p. 20883-20891, Sept. 2021. DOI: 10.1039/d1cp02502c.http://repositorio.ufla.br/jspui/handle/1/48796Physical Chemistry Chemical Physicsreponame:Repositório Institucional da UFLAinstname:Universidade Federal de Lavras (UFLA)instacron:UFLAhttp://creativecommons.org/licenses/by/4.0/info:eu-repo/semantics/openAccessSilva, Daniela RodriguesSantos, Lucas de AzevedoHamlin, Trevor A.Bickelhaupt, F. MatthiasFreitas, Matheus P.Guerra, Célia Fonsecaeng2023-05-29T11:07:11Zoai:localhost:1/48796Repositório InstitucionalPUBhttp://repositorio.ufla.br/oai/requestnivaldo@ufla.br || repositorio.biblioteca@ufla.bropendoar:2023-05-29T11:07:11Repositório Institucional da UFLA - Universidade Federal de Lavras (UFLA)false |
dc.title.none.fl_str_mv |
Dipolar repulsion in α-halocarbonyl compounds revisited |
title |
Dipolar repulsion in α-halocarbonyl compounds revisited |
spellingShingle |
Dipolar repulsion in α-halocarbonyl compounds revisited Silva, Daniela Rodrigues Rotational energy profiles Orbital interactions Electrostatic interactions |
title_short |
Dipolar repulsion in α-halocarbonyl compounds revisited |
title_full |
Dipolar repulsion in α-halocarbonyl compounds revisited |
title_fullStr |
Dipolar repulsion in α-halocarbonyl compounds revisited |
title_full_unstemmed |
Dipolar repulsion in α-halocarbonyl compounds revisited |
title_sort |
Dipolar repulsion in α-halocarbonyl compounds revisited |
author |
Silva, Daniela Rodrigues |
author_facet |
Silva, Daniela Rodrigues Santos, Lucas de Azevedo Hamlin, Trevor A. Bickelhaupt, F. Matthias Freitas, Matheus P. Guerra, Célia Fonseca |
author_role |
author |
author2 |
Santos, Lucas de Azevedo Hamlin, Trevor A. Bickelhaupt, F. Matthias Freitas, Matheus P. Guerra, Célia Fonseca |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Silva, Daniela Rodrigues Santos, Lucas de Azevedo Hamlin, Trevor A. Bickelhaupt, F. Matthias Freitas, Matheus P. Guerra, Célia Fonseca |
dc.subject.por.fl_str_mv |
Rotational energy profiles Orbital interactions Electrostatic interactions |
topic |
Rotational energy profiles Orbital interactions Electrostatic interactions |
description |
The concept of dipolar repulsion has been widely used to explain several phenomena in organic chemistry, including the conformational preferences of carbonyl compounds. This model, in which atoms and bonds are viewed as point charges and dipole moment vectors, respectively, is however oversimplified. To provide a causal model rooted in quantitative molecular orbital theory, we have analyzed the rotational isomerism of haloacetaldehydes OHC–CH2X (X = F, Cl, Br, I), using relativistic density functional theory. We have found that the overall trend in the rotational energy profiles is set by the combined effects of Pauli repulsion (introducing a barrier around gauche that separates minima at syn and anti), orbital interactions (which can pull the anti minimum towards anticlinal to maximize hyperconjugation), and electrostatic interactions. Only for X = F, not for X = Cl–I, electrostatic interactions push the preference from syn to anti. Our bonding analyses show how this trend is related to the compact nature of F versus the more diffuse nature of the heavier halogens. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-09-01 2022-01-06T15:46:08Z 2022-01-06T15:46:08Z |
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 |
SILVA, D. R. et al. Dipolar repulsion in α-halocarbonyl compounds revisited. Physical Chemistry Chemical Physics, [S.l.], v. 23, p. 20883-20891, Sept. 2021. DOI: 10.1039/d1cp02502c. http://repositorio.ufla.br/jspui/handle/1/48796 |
identifier_str_mv |
SILVA, D. R. et al. Dipolar repulsion in α-halocarbonyl compounds revisited. Physical Chemistry Chemical Physics, [S.l.], v. 23, p. 20883-20891, Sept. 2021. DOI: 10.1039/d1cp02502c. |
url |
http://repositorio.ufla.br/jspui/handle/1/48796 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
http://creativecommons.org/licenses/by/4.0/ |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
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 |
Physical Chemistry Chemical Physics reponame:Repositório Institucional da UFLA instname:Universidade Federal de Lavras (UFLA) instacron:UFLA |
instname_str |
Universidade Federal de Lavras (UFLA) |
instacron_str |
UFLA |
institution |
UFLA |
reponame_str |
Repositório Institucional da UFLA |
collection |
Repositório Institucional da UFLA |
repository.name.fl_str_mv |
Repositório Institucional da UFLA - Universidade Federal de Lavras (UFLA) |
repository.mail.fl_str_mv |
nivaldo@ufla.br || repositorio.biblioteca@ufla.br |
_version_ |
1807835153661165568 |