A
kinetic isotope effect in which
, i.e. the heavier substrate reacts more rapidly than the lighter one, as opposed
to the more usual '
normal'
isotope effect, in which
. The
isotope effect will normally be '
normal' when the frequency differences between the isotopic
transition states are smaller than in the reactants. Conversely, an inverse
isotope effect can be taken as evidence for an increase in the corresponding
force constants on passing from the reactant to the
transition state.
Source:
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1130
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.
