Influence of Fluorination on the Conformational Properties and Hydrogen-Bond Acidity of Benzyl Alcohol Derivatives
No Thumbnail Available
Date
Journal Title
Journal ISSN
Volume Title
Publisher
WILEY-VCH Verlag
Abstract
Description
Abstract: The effect of fluorination on the conformational
and hydrogen-bond (HB)-donating properties of a series of
benzyl alcohols has been investigated experimentally by IR
spectroscopy and theoretically with quantum chemical
methods (ab initio (MP2) and DFT (MPWB1K)). It was found
that o-fluorination generally resulted in an increase in the
HB acidity of the hydroxyl group, whereas a decrease was
observed upon o,o’-difluorination. Computational analysis
showed that the conformational landscapes of the title compounds
are strongly influenced by the presence of o-fluorine
atoms. Intramolecular interaction descriptors based on AIM,
NCI and NBO analyses reveal that, in addition to an intramolecular
OH···F interaction, secondary CH···F and/or CH···O interactions
also occur, contributing to the stabilisation of the
various conformations, and influencing the overall HB properties
of the alcohol group. The benzyl alcohol HB-donating
capacity trends are properly described by an electrostatic
potential based descriptor calculated at the MPWB1K/6-31+
G(d,p) level of theory, provided solvation effects are taken
into account for these flexible HB donors.
grant (ANR-13-JS08–0007-01), grant EP/K016938/1, allocation c2014085117, (grant ANR-11-EQPX-0004 funded by the ANR, CCIPL for grants of computer time, EP/K039466/1 and L.M. thanks Mkwawa University College of Education for financial support
grant (ANR-13-JS08–0007-01), grant EP/K016938/1, allocation c2014085117, (grant ANR-11-EQPX-0004 funded by the ANR, CCIPL for grants of computer time, EP/K039466/1 and L.M. thanks Mkwawa University College of Education for financial support
Keywords
hydrogen-bond acidity · benzylic alcohols · conformation analysis · fluorine