Ozone formation in laser flash photolysis of oxoacids and oxoanions of chlorine and bromine

The kinetics of ozone formation in the photolysis of oxygen-containing solutions of HClO, ClO–, ClO–2, ClO–3, HBrO, BrO– and BrO–3 has been studied by laser flash photolysis and conventional flash photolysis. The usual assumption, that ozone only forms in the reaction of oxygen atoms in the spin-triplet ground state with molecular oxygen: O + O2→ O3 subsequent to the primary process [graphic omitted] is found to be valid for solutions at pH ⩽ 10 but not for more strongly alkaline solutions. The rate constants of the reactions of O with O2 and BrO–3 are found to be 4.0 × 109 and 1.5 × 107 dm3 mol–1 s–1, respectively. The formation of ozone in strongly alkaline solutions can be accounted for by the additional processes O–3+ XO–n– 1→ O3+ XO–n– 1 with rate constants in the range 5 × 108 to 1.5 × 109 dm3 mol–1 s–1 subsequent to O–+ O2⇌ O–3 and the primary process [graphic omitted].