Theoretical study of the reaction mechanism for HNCS with NO radical

The reaction mechanisms of HNCS with NO radical have been systematically investigated using abinitio(HF method)at the HF/ 6-31+G(d,p) level. The geometries of the transition states, the intermediates have been completely optimized. The transition states and intermediates of these reactions are verified by frequency analysis. The relation ship of reactants, transition states, intermediates and products is affirmed by IRC. The energies of all species have also been further calculated using QCISD(T). The results show that the reaction HNCS+NO involves three channels. By the energy barriers and thermodynamic quantities comparison, the third channel in which the HNN and SCO have been produced is the dominant one.