Use of the Brönsted equation in the interpretation of micellar effects in kinetics. Study of the reaction [Fe(CN)5(4-CNpy)]3-+CN-⇌Fe(CN)64-+4-CNpy in SDS micellar solutions

Abstract

A study of the reaction [Fe(CN)₅(4-CNpy)]^3-+CN^-⇄Fe(CN)₆^4-+4-CNpy was carried out in sodium dodecyl sulfate (SDS) micellar solutions. We conclude that the well known pseudophase model, an extension of the Olson–Simonson treatment to micellar solutions, is equivalent to the Brönsted equation in regard to rationalization of the micellar effects on reactivity. The equivalence follows from the fact that both pseudophase and Brönsted approaches can be used to rationalize kinetic data, as well as from thermodynamic considerations.