The
linear free-energy relation of the form:
applied to the variation of
reactivity of a given
electrophilicsubstrate towards a series of nucleophilic reagents.
is characteristic of the
reagent (i.e. a measure of its
nucleophilicity) and
is characteristic of the substrate (i.e. a measure of its sensitivity to the
nucleophilicity of the
reagent). A scale of
values is based on the rate coefficients
for the reaction of methyl bromide with nucleophiles in water at
,
being defined as 1.00 for these reactions and
being defined as 0.00 for the
hydrolysis of methyl bromide. (Other scales have been devised.)
Source:
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1169
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.
