The equation in the form:
or
applied to the influence of
meta- or
para-substituents X on the reactivity of the
functional group Y in the benzene derivative
m- or
p-
XC6H4Y.
or
is the rate or
equilibrium constant, respectively,
for the given reaction of
m- or
p-
XC6H4Y;
or
refers to the reaction of
C6H5Y,
i.e.
X
=
H;
is the substituent constant characteristic of
m- or
p-
X: is the reaction constant characteristic of the given reaction of Y. The equation is often encountered in a form with
or
written as a separate term on the right hand side, e.g.
or
It then signifies the intercept corresponding to
X
=
H
in a regression of
or
on
.
Source:
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1119
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.
doi:10.1351/goldbook.
