The @L03551@ \[\log _{10}k_{\text{N}} = \log _{10}k_{0}+N_{\text{+}}\] applied to the reactions between nucleophiles and certain large and relatively @S05900@ organic cations, e.g. arenediazonium, triarylmethyl and aryltropylium cations in various solvents. \(k_{\text{N}}\) is the @O04322@ for reaction of a given @C00907@ with a given nucleophilic system (i.e. given nucleophile in a given solvent). \(k_{0}\) is the @O04322@ for the same @C00907@ with water in water, and \(N_{\text{+}}\) is a parameter which is characteristic of the nucleophilic system and independent of the @C00907@. A surprising feature of the equation is the absence of a @C01124@ of \(N_{\text{+}}\), characteristic of the substrate (cf. the \(s\) in the @S06201@), even though values of \(N_{\text{+}}\) vary over 13 log units. The equation thus involves a gigantic breakdown of the @R05186@. The equation has been extended both in form and in range of application.
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1161 [Terms] [Paper]