QUASI-CLASSICAL STUDY OF STEREO-DYNAMICS FOR THE REACTION C + CH → C2 + H ON THE 12A′ POTENTIAL ENERGY SURFACE

摘要

The quasi-classical trajectory (QCT) method and the 12A′ potential energy surface (PES) [Boggio-Pasqua et al., Phys Chem Chem Phys2:1693, 2000] have been employed to study the stereo-dynamics of the reaction C + CH (v = 0, j) → C2 + H at different collision energies over the range of 0.01–0.6 eV and for different rotational quantum number j = 0 - 3. The reactive total cross section with initial revibrational state of v = 0 and j = 0 as a function of collision energy is presented and compared with the quantum mechanics results. The forward-backward asymmetry phenomenon has been found in the angular distribution of the products. The calculated distribution of P(θr) indicates a strong product alignment perpendicular to k, but this kind of product alignment is found to be rather insensitive to the collision energy. The calculated distribution of P(ϕr) revealed that at low collision energy the products tend to be oriented along the negative direction of the y-axis, while at high collision energy, this product orientation tends to be pointed to the positive direction of the y-axis. Such product orientation tends generally to become stronger with the increase of collision energy. Further, product polarization (i.e. orientation and alignment) becomes weak with high rotational excitation of the reagent CH molecule.