GROUP SIX TRIATOMIC OXIDES

Sulfur dioxide (2,4) and oxone are important atmospheric constituents. Particularly ozone acts as a radiation shield of sunlight below about 300 nm. A great deal of work has been done to understand the photodissociation dynamics of these molecules. While a great deal of progress has been made, it will be clear from the following discussion that much remains to be done for complete understanding. 

Above 218 nm, below the dissociation limit, fluorescence from the SO2 (CI-B2) state has been observed. 

The self-quenching rate constant of 21 x 10 cm /molecule s that was measured in these studies is unusually large (69). Quenching by various gases and collision induced rotational transitions have also been measured (68,69). The quenching cross sections by He and Ar in a supersonic jet increase at very low temperature (70), indicating the formation of collision complexes.  

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