A curve describing the variation of the potential energy of the system of atoms that
make up the reactants and products of a reaction as a function of one geometric coordinate,
and corresponding to the '
energetically easiest passage' from reactants to products (i.e. along the line produced by joining the paths of
steepest descent from the
transition state to the reactants and to the products). For an
elementary reaction the relevant geometric coordinate is the
reaction coordinate ; for a
stepwise reaction it is the succession of reaction coordinates for the successive individual reaction
steps. (The
reaction coordinate is sometimes approximated by a quasi-chemical index of reaction progress, such as
'
degree of atom transfer' or
bond order of some specified bond.)
Source:
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1151
PAC, 1996, 68, 149
(A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC
Recommendations 1996))
on page 176
Cite as:
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.
