Reactions of the HO2 radical in aqueous solution with bromine and related compounds

Abstract

A flow system has been used to produce HO₂ in concentrations up to 38 µM by the radiolysis of oxygen saturated aqueous formate solutions. Rate constants for the following reactions have been obtained by competitive studies, relative to the known rate of reaction of O^–₂ with tetranitromethane: HO₂+ Br₂→ H⁺+ O₂+ Br^–₂k=(1.1^+0.6_–0.4)× 10⁸ M^–1 s^–1, O^–₂+ Br₂→ O₂+ Br^–₂k=(5.6 ± 0.7)× 10⁹ M^–1 s^–1, HO₂+ Br^–₃→ H⁺+ O₂+ Br^–+ Br^–₂k < 10⁷ M^–1 s^–1, O^–₂+ Br^–₃→ O₂+ Br^–+ Br^–₂k=(3.8 ± 0.7)× 10⁹ M^–1 s^–1, O^–₂+ HOBr → OH^–+ O₂+ Br k=(9.5 ± 0.8)× 10⁸ M^–1 s^–1