The Fluorine gauche effect and a comparison with Other halogens in 2‐Halofluoroethanes and 2‐Haloethanols

Registro completo de metadados
MetadadosDescriçãoIdioma
Autor(es): dc.creatorMartins, Francisco A.-
Autor(es): dc.creatorFreitas, Matheus P.-
Data de aceite: dc.date.accessioned2026-02-09T12:29:42Z-
Data de disponibilização: dc.date.available2026-02-09T12:29:42Z-
Data de envio: dc.date.issued2020-05-12-
Data de envio: dc.date.issued2020-05-12-
Data de envio: dc.date.issued2019-10-09-
Fonte completa do material: dc.identifierhttps://repositorio.ufla.br/handle/1/40849-
Fonte completa do material: dc.identifierhttps://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/ejoc.201901234-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/capes/1162423-
Descrição: dc.descriptionWhile the gauche effect in 1,2‐difluoroethane is widely known as being due to hyperconjugative interactions between σCH electron‐donating orbitals and σ*CF electron‐accepting orbitals, the corresponding 1,2‐dichloro, 1,2‐dibromo, and 1,2‐diiodo derivatives are preferentially in the anti conformation. 2‐Halofluoroethanes (F‐CH2‐CH2‐X) combine a small halogen (fluorine) and a vicinal low‐lying energy antibonding orbital (σ*CX) that activates a stabilizing antiperiplanar σCH → σ*CX electron delocalization, which can induce the gauche effect. On the other hand, σCX orbitals are good electron donors to σ*CF, that would favor an “anti effect”, in addition to traditional interpretations based on steric and electrostatic repulsion. Therefore, a balance of steric, dipolar and hyperconjugative effects drive the conformational equilibrium of these compounds – hyperconjugation was found to explain the gauche effect in some cases, whilst Lewis‐type interactions determine the anti preference in others. The gauche effect takes place in a polar solvent, but not for 1‐fluoro‐2‐iodoethane. According to NMR three‐bond spin‐spin coupling constants, the gauche population increases when fluorine is replaced by a hydroxyl group (except for 2‐fluoroethanol relative to 1,2‐difluoroethane), but this is not primarily due to intramolecular hydrogen bond.-
Idioma: dc.languageen-
Publicador: dc.publisherWiley-
Direitos: dc.rightsrestrictAccess-
???dc.source???: dc.sourceChemistry Europe-
Palavras-chave: dc.subjectDipolar interactions-
Palavras-chave: dc.subjectHyperconjugation-
Palavras-chave: dc.subjectSteric effects-
Palavras-chave: dc.subjectIntramolecular hydrogen bonds-
Palavras-chave: dc.subjectInterações dipolares-
Palavras-chave: dc.subjectHiperconjugação-
Palavras-chave: dc.subjectEfeitos estéricos-
Palavras-chave: dc.subjectLigações intramoleculares de hidrogênio-
Título: dc.titleThe Fluorine gauche effect and a comparison with Other halogens in 2‐Halofluoroethanes and 2‐Haloethanols-
Tipo de arquivo: dc.typeArtigo-
Aparece nas coleções:Repositório Institucional da Universidade Federal de Lavras (RIUFLA)

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