Ab initio Investigation of the C2（a 3Πu）+NO Reaction

The reaction mechanism of C2（a 3Πu）+ NO is investigated at the level of G2（CC，MP2）. The equilibrium geometries，harmonic frequencies and energy of various stationary points on the potential energy surfaces have been calculated in the lowest doublet states. It is found that there are two reaction mechanisms：one is CCON mechanism that begins from O atom of NO attacks C2 and the intermediate is CCON；the other is called CCNO mechanism for its intermediate is CCNO formed by N atom of NO attacks C2 . In the same time，the five possible ground product pathways corresponding to these two mechanisms for this reaction are analysed and concluded that the pathway that O atom of NO attacks C2 to produce the major products CN+CO via CCNO mechanism is the most favorable pathway.