Influence of Sodium Pentadecylsulfonate on the Rate of Diphenylamine Oxidation by Peroxidisulfate in Water-Dioxane Mixtures

The kinetics of the reaction of Ph₂NH (A) with S₂O^2-₈ under O₂ free condition was studied in homogenous medium using H₂O+dioxane (33% by volume) solution in presence of the PDS anion active micelles. In absence of PDS micelles, Ph₂NH oxidation is consecutive, the final product being diphenylbenzidine violet. When PDS micelles are present, the over-all reaction rate decreases. At [E-30]₀ ≥ 0.16 M, the reaction is stopped at the stage of tetraphenylhydrazine (TPhH) formation, which leads to slowing down of the over-all rate of S₂O^2-₈ consumption. This fact has been explained assuming that water soluble S₂O^2-₈ and oil-soluble TPhH are localized in different loci in the reaction medium. The distribution coefficient (P_A) of the reductant between micellar and water as well as water-EtOH-dioxane solutions has been determined.