Studies in cyclophosphazenes. Part III. The kinetics of the reactions of chlorocyclotriphosphazenes with methylamine in tetrahydrofuran

Abstract

A kinetic study of the reactions of hexachlorocyclotriphosphazene and methylaminopentachlorocyclotriphosphazene with methylamine in tetrahydrofuran has been conducted at three temperatures. In conformity with the observed orders of reaction and the magnitudes of the enthalpies and entropies of activation calculated, a two-step mechanism involving the formation of an intermediate which subsequently decomposes by solvent-assisted dehydrochlorination, is proposed. This mechanism is extended by comparing the values of the activation parameters found in this study with those evaluated previously in studying the corresponding reactions with dimethylamine. The results are interpreted by considering the differences of basicity and steric requirements of the two amines in each step of the reaction.