Studies on the transient species formed in the pulse radiolysis of benzotriazole

Rate constants for the reaction of benzotriazole (BTZ) with the primary species of water radiolysis (e.g. eaq-, OH, H and O-) have been determined at different pHs using the pulse radiolysis technique. Absorption spectra of the transient intermediates formed have been recorded in the region 220-650 nm. Semireduced radicals formed by eaq- reaction with benzotriazole are found to be strongly reducing in nature and they transfer electrons to various acceptors such as thionine, methylene blue, paraquat with diffusion controlled rate constants. Only SO4- radicals were found to oxidize benzotriazole. Reactivity of BTZ towards eaq- and specific oxidants has been compared with that of indole. Evidence for characterization of both semireduced and semioxidized benzotriazole as three electron bonded species are given. (author)