A detailed description of the process leading from the reactants to the products of
a reaction, including a characterization as complete as possible of the composition,
structure, energy and other properties of
products and transition states
. An acceptable mechanism of a specified reaction (and there may be a number of such
alternative mechanisms not excluded by the evidence) must be consistent with the reaction
, the rate law
and with all other available experimental data, such as the stereochemical course
of the reaction. Inferences concerning the electronic motions which dynamically interconvert
successive species along the reaction path
(as represented by curved arrows, for example) are often included in the description
of a mechanism. It should be noted that for many reactions all this information is
not available and the suggested mechanism is based on incomplete experimental data.
It is not appropriate to use the term mechanism to describe a statement of the probable
in a set of stepwise reactions. That should be referred to as a reaction sequence
, and not a mechanism.
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1138
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook