Formation of hydrated electron and BrO3 center dot radical from laser photolysis of BrO3- aqueous solution

Hydrated electron, as well as BrO3. radical was observed as one of the prod ucts from the laser photolysis of bromate (BrO3-) aqueous solution, with an initial quantum yield of (8.0 +/- 0.8) x 10(-2) determined. The hydrated e lectron produced can be scavenged rapidly by O-2,( OH)-O-. radical and the parent compound BrO3-. The rate constant for the reaction of e(aq)(-) with BrO3- was determined to be 3.0 x 10(9) dm(3) mol(-1) s(-1) at ionic strengt h I = 0. The BrO3. radical was observed to have an absorption peak at 315 n m with a molar absorption coefficient of similar to 8 x 10(2) dm(3) mol(-1) cm(-1). In addition, BrO3. could be also produced from the electron transf er reaction of the sulfate radical (SO4.-) with BrO3-. The radical prefers to dissociate rapidly to form the BrO. radical (at a rate of > 2.0 x 10(5) s(-1)). It was also suggested that some of the BrO. came from direct photol ysis of BrO3- solution. Quantum yields of BrO2. and O from the photolysis o f BrO3- were determined to be 0.12 +/- 0.01 and (7.4 +/- 0.6) x 10(-3), res pectively.