Theoretical study of CH 3CH=CH 2+O( 1D) reaction: Mechanism and kinetics

The mechanism and kinetics for the reaction of propene(CH 3CH=CH 2) molecule with O( 1D) atom were investigated theoretically. The electronic structure information of the potential energy surface(PES) was obtained at the B3LYP/6-311+G(d,p) level, and the single-point energies were refined by the multi-level MCG3-MPWB method. The calculated results show that O( 1D) atom can attack CH 3CH=CH 2 via the barrierless insertion mechanism to form four energy-riched intermediates CH 3C(OH)CH 2(IM1), CH 3CHCHOH(IM2), CH 2OHCHCH 2(IM3) and cyclo-CH 2OCHCH 3(IM4), respectively, on the singlet PES. The branching ratios as well as the pressure- and temperaturedependence of various product channels for this multi-well reaction were predicted by variational transition-state and Rice-Ramsperger-Kassel-Marcus(RRKM) theories. The present results will be useful to gain a deep insight into the reaction mechanism and kinetics of CH 3CH=CH 2+O( 1D) reaction.