The mechanism of the oxidation of thiocyanate ion by peroxomonosulphate in aqueous solution. III. Interpretation of results

Abstract

The mechanistic implications of the results presented previously are discussed. There is strong evidence that the reactants are in equilibrium with an intermediate and some of the reactions of this intermediate have been observed; thiooyanogen appears to be another intermediate. Schematically, the reaction involves the pathways:

Diagram

The identity of X has not been established though suggestions are made.

The initial-rate procedure which was used to predict this scheme involves some unusual assumptions and uses only a small portion of the available kinetic data. Hence the proposed mechanism (and several alternatives) was tested by numerical integration of the implied differential equations and comparison of calculated and experimental kinetic curves. Such calculations avoided several of the undesirable features of the analysis of initial rates and established the essential adequacy of the above scheme; a detailed mechanism is proposed.

These calculations illustrate the usefulness of techniques of numerical integration in evaluation of reaction mechanisms.