Dynamics of SO(A3Π) formation in an argon + SO2 afterglow

The SO(A → X) fluorescence resulting from the Ar(³P_2,0)+SO₂ reaction has been studied in a flowing afterglow system. Various reaction pathways for the formation of the SO(A) fragment have been considered. A linear surprisal analysis of the vibrational distributions indicates that the resonance excitation with subsequent predissociation of the intermediate bound state is responsible for the formation of SO(A). A significant fraction of the available energy has been found to be partitioned into translation. Because the predissociation of SO₂ in the exit channel is dominating the reaction pathway in the Ar^*+SO₂ → Ar+O+SO(A) system, all the dynamical features can then be explained by the simple classical treatments on the dissociation of SO₂.