ABSTRACT
When two competing mechanisms are considered, for example, a competition parameter may thus be defined as the ratio of the average concentration of the key species obtained when each of these mechanisms is considered alone. Let us denote by C I and C2 the corresponding concentrations for mechanisms 1 and 2 in Scheme 2, when they do not interfere. The competition parameter p = C1/C2 is then such that p « 1 favors the occurrence of mechanism 1 as the main pathway since this condition corresponds to C1 « C2, whereas mechanism 2 is observed when p » I. In the general case the dependence of both C1 and C2 on the experimental conditions (concentrations of the reactants and of the coreactants, stirring rate, and so on) and intrinsic factors (rate constants and diffusion coefficients, for example) may be determined, thus leading to the expression of p as a function of these factors. The effects of the latter on the overall product distribution are then readily given with the direction and magnitude included in the p expression.
