| Comments |
"As...seen, hydrogen bonds exist with a continuum of
strengths. Nevertheless, it can be useful for practical reasons
to introduce a classification, such as "weak", "strong", and
possibly also "in between". In this article, the system
described by Jeffrey is followed, (primary source) who called hydrogen bonds
moderate if they resemble those between water molecules or
in carbohydrates (one could also call them "normal", and are
associated with energies in the range 4 - 15 kcal/mol. Hydrogen
bonds with energies above and below this range are
termed strong and weak, respectively. Some general properties
of these categories are listed in Table 2. It must be stressed
that there are no "natural" borderlines between these categories, and that there is no point in using this or any
related system in too stringent a way. For a comment on the
names of the categories, see footnote [58, beneath table]." |