基于4A"势能面研究C(3P)+NO(X2Π)→CO(X1Σ+)+N(4S)反应的立体动力学性质

运用准经典轨线方法(QCT), 基于Abrahamsson等构造的⁴A"势能面(Abrahamsson E Andersson S, Nyman G, Markovic N 2008 Phys. Chem. Chem. Phys. 10 4400), 在碰撞能为0.06 eV时, 对C(³P)+NO(X²Π )→CO(X¹Σ⁺)+N(⁴S)反应立体动力学性质进行了理论研究. 在考虑反应物NO转动和振动激发的条件下, 计算了质心坐标系下k-j'矢量(k与j'分别为反应物速度与产物角动量)相关的P(θ_r)分布和k-k'-j'矢量(k'为产物相对速度)相关的P(φ_r)分布. 此外还计算了该反应的三个极化微分截面(2π/σ)(dσ₀₀/dω_t), (2π/σ)(dσ₂₀/dω_t)以及(2π/σ)(dσ₂₂+dω_t). 计算结果表明转动和振动激发对产物取向影响较大而对定向影响较小; 对于三个极化微分截面, 转动激发的影响不大, 而振动激发的影响则较大.

Exploring the stereodynamics of C(3P)+NO(X2Π)→CO(X1Σ+)+N(4S) reaction on 4A" potential energy surface

Studies on the dynamical stereochemistry of the titled reaction are carried out by the quasi-classical trajectory (QCT) method based on a new accurate ⁴A" potential energy surface constructed by Abrahamsson and coworkers (Abrahamsson E Andersson S, Nyman G, Markovic N 2008 Phys. Chem. Chem. Phys. 10 4400) at a collision energy of 0.06 eV. The distribution p(θ_r) of the angle between k-j' and the angle distribution P(φ_r in terms of k-k'-j' correlation have been calculated. Results indicate that the rotational angular momentum vector j' of CO is preferentially aligned perpendicular to k and also oriented with respect to the k-k' plane. Three polarization-dependent differential cross sections (2π/σ)(dσ₀₀/dω_t), (2π/σ)(dσ₂₀/dω_t), and (2π/σ)(dσ₂₂+/dω_t) have also been calculated. The preference of backward scattering is found from the results of (2π/σ)(dσ₀₀/dω_t). The behavior of (2π/σ)(dσ₂₀/dω_t) shows that the variation trend is opposite to that of (2π/σ)(dσ₀₀/dω_t), which indicates that j' is preferentially polarized along the direction perpendicular to k. The value of (2π/σ)(dσ₂₂/dω_t) is negative for all scattering angles, indicating the marked preference of product alignment along the y-axis. Furthermore, the influences of initial rotational and vibrational excitation on the reaction are shown and discussed. It is found that the initial vibrational excitation and rotational excitation have a larger influence on the alignment distribution of j' but a weaker effect on the orientation distribution of j' in the titled reaction. The influence of the initial vibrational excitation on the three polarization-dependent differential cross sections of product CO is stronger than that of the initial rotational excitation effect.