DFT study on the mechanisms of the CH₂CO+NCX (X=O, S) reactions

A detailed theoretical survey on the potential energy surface for the CH₂CO+NCX(X=O, S) reaction is carried out at the QCISD/6-311+G(d, p)//B3LYP/6-311+G (d, p) level. The geometries, vibrational frequencies and energies of all stationary points involved in the reactions are calculated at the B3LYP/6-311+G(d, p) level. And the more accurate energy information is provided by single point calculations at the QCISD(T)/6-311+G(d, p) level. Relationships of the reactants, transition states, intermediates and products are confirmed by the intrinsic reaction coordinate (IRC) calculations. The calculations suggest that the channel producing CH₂NCO+CO is the dominant one, and CH₂NCO+CO is the major product for the CH ₂CO+NCO reaction. The results are in good agreement with experiments. And similarly, product CH₂NCS+CO is the most important product for the CH₂CO+NCS reaction.