The reaction between methyl radicals and nitric oxide has been studied by using the B3LYP/6-311G** and the high-level electron-correlation CCSD(T)/6-311G** levels. The geometries of reactants, the transition states and the products were completely optimized. All the transition states are verified by the vibrational analysis and the internal reaction coordinate (IRC) calculations. The results show that the reaction is of multi-channel and multi-step. It may proceed on singlet and triplet potential energy surface (PES). Eight products, P1～P8, are obtained via the complex reaction channels, i.e. association, H-shift and dissociation.

Key words: reaction mechanism, methyl radical, nitric oxide, density functional theory