Theoretical investigation on the radical-neutral reaction mechanism of CP with CH2CO and the structural nature of several low-lying intermediates

The reaction channels and mechanism of CP with CH2CO were investigated at the B3LYP/6-311++G(d,p) and QCISD(T)/6-311++G(2df,2p) (single-point) levels of computation. The computation results demonstrated that the reaction, proceeding through a barrierless initial attack by the carbon atom of CP at the β-carbon atom of CH2CO leading to the formation of PCCH2CO followed by a direct dissociation into the major products CH2CP + CO via a CC bond rupture reaction, can be considered as the dominant pathway in the reaction kinetics of CP with CH2CO. By comparison with the CN + CH2CO system, it can be known that the two reactions possess quite similar reaction mechanism and product distribution. Furthermore, the structural nature of several thermodynamically favorable intermediates was investigated. Also, the ring strain energies of two low-lying cyclic intermediates were calculated for illuminating their slightly high thermodynamic stabilities relative to another two chainlike low-lying intermediates.