Theoretical study on the reaction path and varitional rate constant reaction H+CH3NO2→H2+CH2NO2

Using ab initio theory, the geometries of the reactants, transition state, and products of the reaction H + CH3NO2 --> H-2 + CH2NO2 have been optimized at the UMP2(full)/6-311G** level. The forward and reverse reaction potential barriers are 82.73 and 57.14 kJ/mol respectively. The reaction, that is the formation of H-H bond and breaking of C-H bond, has been shown by a coordination process. Furthermore vibration normal-mode are discussed along the IRC, it is clear that there is a reactivity normal-mode which leads the reaction from reactants to product. The forward reaction theoretical rate constant obtained by using the Variational transition-state theory (CVT), are consistent with experimental value at the reaction temperature 1000-1400 K.