This term is sometimes applied to an
elementary reaction which proceeds via an intermediate species having a lifetime longer than a few rotational
periods, in contrast to a
direct reaction. However, in view of the danger of confusion with a reaction occurring in more than
one step (a
composite reaction ) this usage is not to be recommended; it is better to use the terms complex-
mode mechanism or
complex-mode reaction.
Source:
PAC, 1996, 68, 149
(A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC
Recommendations 1996))
on page 160
