Homogeneous Elementary Reactions in the Atmosphere and Rate Constants

Homogeneous Elementary Reactions in the Atmosphere and Rate Constants 

Sequential oxidation reaction mechanisms of many organic molecules emitted into the atmosphere and the overall reaction system with HOx chain reaction mechanism in the troposphere are treated in Chap. 7, and the HOx, NOx, ClOx chain reaction systems in the stratosphere are described in Chap. 8. 

Akimoto, Atmospheric Reaction Chemistry, Springer Atmospheric Sciences, DOI 10.1007/978 31-55870-5 5 

Reactions of oxygen atoms fonned in the photolysis of atmospheric O2,03, NO2 are initial triggers to drive stratospheric and tropospheric chemistiy system. Oxygen atoms targeted in the stratospheric and tropospheric chemistiy are 0( P) in the ground state, and 0( D) in the lowest excited state at 190 kJ mol higher than the ground state. 

0( P) can react with many organic and inorganic molecules but the reactivity is much lower than 0( D). Thus, although hydrocarbons existing in the clean and polluted troposphere can all react with 0( P), the reactions can in general be neglected as compared to those with OH radicals when atmospheric concentrations of 0( P) and reaction rates are considered, and only the reaction with the atmospheric main species O2 is necessary to be considered as the 0( P) reaction in the troposphere. In the stratosphere, reactions with O2 and O3 are predominant, but those with OH, HO2, NO2, CIO are also important in the chain reaction system. 

---