Gas Phase Halogen Chain Reaction

These reactions constitute chain cycle to cause net O3 dissipation, 

However, the actual reaction of XO + YO follow the pathways other than reaction (7.84) depending on different kinds of halogens, and they have to be considered for the detailed analysis of reaction mechanism. 

For example, the reaction of CIO + CIO under the atmospheric pressure proceeds almost solely as. 

As for the photolysis of OIO in reaction (7.105), the quantum yield of tmity is reported in the experiment (Gomez Martin et al. 2009). The absorption spectrum and photolytic processes of the chain carriers, CIO, BrO, lO, which result in the depletion of O3 by the reactions (7.82), (7.83) and (7.84), have been described in Chap. 4, Sect. 4.4.5. 

For such a gas phase chain reaction, radical-radical reactions (7.84, 7.86-7.88) predominate when the mixing ratios of halogen radicals (XO) exceed e.g. 3 pptv. However, as their mixing ratios decrease, the formation of HOX by the reaction of XO with HO2, 

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