Internal energy distributions of the SO(X)3Σ−) product from the O(3P) + OCS reaction

The SO(X3Σ−) product vibrational and rotational state distributions following the title reaction have been studied by laser induced fluorescence on the (B3Σ−-X3Σ−) transition. The O(3P) atom was generated by 351 nm photolysis of NO2. The SO(X3Σ−) product is highly vibrationally excited and the vibrational state distribution is inverted at v″=5 with detectable population up to v″=9. The observed vibrational state distribution has been modelled effectively by a Franck-Condon/Golden Rule treatment. The nascent rotational state distribution of v″=4 and 6 can be characterized by rotational temperatures, TR=2288±357 K and TR=2227±297 K, respectively. The rotational state populations are nearly equilibrated with the ambient gas within 10 hard sphere collisions. A surprisal analysis reveals that the observed rotational state distribution is colder than would be predicted on the basis of a purely statistical energy disposal model. The observed SO(X3Σ−) internal energy accounts for ≈ 34% of the total energy available to products. The non-statistical energy disposal results are consistent with a direct S atom abstraction mechanism.