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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

There and back again: the role of hyperconjugation in the fluorine gauche effect

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Author(s):
Port, Vinicius C. [1] ; Cormanich, Rodrigo A. [1]
Total Authors: 2
Affiliation:
[1] Univ Estadual Campinas, Chem Inst, Monteiro Lobato St, BR-13083862 Campinas, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Physical Chemistry Chemical Physics; v. 23, n. 32 JUL 2021.
Web of Science Citations: 0
Abstract

The origin of the fluorine gauche effect has been debated for decades and recently different interpretations have been raised in the scientific community as new computational methods emerged and were applied to rationalize 1,2-difluoroethane (DFE) gauche preference. In this context, we revisited 1,2-difluoroethane (DFE) and its chlorine and bromine derivative conformational preferences through a comparative approach: the conformational behavior and hyperconjugative, steric and electrostatic contributions for the internal rotational barrier of DFE were compared with several analogue backbones, such as peroxides, disulfides and ammonia boranes. By using the Natural Bond Orbital (NBO) analysis it was found that hyperconjugation is the driving force of the conformational preference in DFE and its chlorine and bromine analogues. Electrostatics was found to be negligible and steric effects played a minor role in general, but are important in ClCH2CH2Cl and BrCH2CH2Br to counterbalance gauche stabilization by hyperconjugation and for the preference of the anti conformer. (AU)

FAPESP's process: 18/03910-1 - Physicochemical studies of fluorinated organic compounds: experimental and theoretical approaches
Grantee:Rodrigo Antonio Cormanich
Support Opportunities: Research Grants - Young Investigators Grants