Preferred Label : Ritchie equation;
IUPAC definition : The linear free-energy relation \[\log _{10}k_{{N}} \log _{10}k_{0} N_{{ }}\] applied
to the reactions between nucleophiles and certain large and relatively stable organic
cations, e.g. arenediazonium, triarylmethyl and aryltropylium cations in various solvents.
kN is the rate constant for reaction of a given cation with a given nucleophilic system
(i.e. given nucleophile in a given solvent). k0 is the rate constant for the same
cation with water in water, and N is a parameter which is characteristic of the
nucleophilic system and independent of the cation. A surprising feature of the equation
is the absence of a coefficient of N , characteristic of the substrate ( i cf /i
. the s in the Swain–Scott equation), even though values of N vary over 13 log units.
The equation thus involves a gigantic breakdown of the reactivity–selectivity principle.
The equation has been extended both in form and in range of application.;
Origin ID : R05402;
See also
The linear free-energy relation \[\log _{10}k_{{N}} \log _{10}k_{0} N_{{ }}\] applied
to the reactions between nucleophiles and certain large and relatively stable organic
cations, e.g. arenediazonium, triarylmethyl and aryltropylium cations in various solvents.
kN is the rate constant for reaction of a given cation with a given nucleophilic system
(i.e. given nucleophile in a given solvent). k0 is the rate constant for the same
cation with water in water, and N is a parameter which is characteristic of the
nucleophilic system and independent of the cation. A surprising feature of the equation
is the absence of a coefficient of N , characteristic of the substrate ( i cf /i
. the s in the Swain–Scott equation), even though values of N vary over 13 log units.
The equation thus involves a gigantic breakdown of the reactivity–selectivity principle.
The equation has been extended both in form and in range of application.
