ClO + ClO → Products: A Case Study in Halogen Monoxide Disproportionation and Recombination Reactions

The phenomenon of ozone depletion in the springtime Arctic boundary layer is similar in several respects to the ozone hole in the Antarctic stratosphere. In both cases, heterogeneous chemistry on ice and acid-ice surfaces may be responsible for altering the partitioning of halogen-containing species between long-lived and photochemically labile forms. As a result of this repartitioning, the mixing ratios of ClO and BrO radicals become sufficiently high that self-reactions of these species can become the dominant rate-limiting steps in catalytic ozone destruction cycles. It is important, therefore, to understand the rates and mechanisms of these reactions under ambient atmospheric conditions.