The capability of a molecule to undergo fast and reversible
intramolecularisomerization, the energy barrier to which is lower than that allowing for the preparative isolation
of the individual isomers at room temperature. It is conventional to assign to the
sterochemically non-rigid systems those compounds whose molecules rearrange rapidly
enough to influence
NMR line shapes at temperatures within the practical range (from
to
)
of experimentation. The energy barriers to thus defined rearrangements fall into the
range of
–
(
–
).
Source:
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.
