Theoretical study on the reaction mechanism of CH3CH2O radical with NO

The reaction mechanism of CH3CH2O radical with NO was investigated by using M06-2X, MP2 and CCSD(T) methods with 6-311++G(d, p) basis set. Five reaction pathways on the singlet and four reaction pathways on triplet potential energy surfaces (PES) were found. The geometries of the reactants, complexes, transition states, and products were optimized. The calculated results showed that CH3CHO and HNO are the main products, no matter on the singlet or triplet-state PES. CH3CH2ONO should also be observed in experiment. The calculated results successfully explained the Bras’s experimental results. The cleavage and formation of the chemical bonds in the dominant reaction pathway were probed by the topological analysis of electronic density. It is found that a non-planar four-member-ring transition structure appears on the reaction path, and it changes to a three-member-rings structure by the slip of C–H bond.