Reactions of dibenzoyldiazene. Part 2. Thermal and photochemical decompositions in benzene solution

Abstract

E.s.r. and microsecond flash-photolysis studies indicate that in benzene solution hydrazyl radicals formed by the addition of various precursor radicals to dibenzoyldiazene are deactivated through a second-order process, yielding the corresponding hydrazines. This process occurs in parallel with a pseudo-first-order reaction with dibenzoyldiazene in which an oxygen atom is transferred, yielding the corresponding hydrazoxyl radical and diphenyloxadiazole. A structure–reactivity correlation is noted, and the role played by these reactions in the inhibition and retardation of the radical polymerization of vinyl monomers is discussed.