Abstract
For more than three decades, the ability of a fluorine atom involved in a C–F bond
to act as a hydrogen-bond acceptor has been a controversial issue. Throughout the
years, more and more evidence has been published to support this hypothesis and it
is now difficult to doubt the existence of the hydrogen bond with organic fluorine.
However, since this interaction has low binding energies, it is sometimes difficult
to clearly demonstrate its presence or effect in a system. In the present review,
only the most recent examples from the literature are presented and the different
techniques used to prove the presence of these C–F···H–X hydrogen bonds are compared
and discussed according to the accepted criteria for hydrogen bonding detailed by
a recent IUPAC committee. Even with its weak interaction energy, hydrogen bonds to
organic fluorine have the potential to affect properties of practical systems in different
spheres of chemistry. All the recent examples of such effects are highlighted.
1 Introduction
2 Properties
3 C(sp2)–F
3.1 O–H as Donor
3.2 N–H as Donor
3.3 C(sp2)–H as Donor
3.4 C(sp3)–H as Donor
4 C(sp3)–F
4.1 O–H as Donor
4.2 N–H as Donor
4.3 C(sp2)–H as Donor
4.4 C(sp3)–H as Donor
5 Conclusion
Key words
organofluorine chemistry - weak hydrogen bonds - spectroscopic measurements - X-ray
crystallography - computational analysis
