全维高精度势能面上F+CH3OH反应的产物振动态分布

甲醇与氟原子之间的抽氢反应可以生成HF和CH₃O、CH₂OH自由基等产物. 该反应在环境化学、燃烧化学、辐射化学和星际化学中都非常重要. 基于之前构建的全维高精度势能面，本文采用准经典轨线方法研究了该典型反应的动力学. 特别是使用正则模式分析方法确定了多原子产物CH₃O和CH₂OH的振动态分布. 研究发现，当反应物处于振转基态时，CH₃O和CH₂OH主要分布在基态. 当反应物CH₃OH的OH伸缩模式激发为第一激发态时，产物CH₂OH的OH伸缩模式、扭转模式、H₂CO 面外弯曲模式及其组合会被有效激发. 在两条通道中，可用能量大部分都流入HF的振动能和产物的平动能，而自由基产物CH₃O或CH₂OH只得到非常少的能量，与实验结果一致，这也表明了自由基的旁观者性质.

Product Vibrational State Distributions of F+CH3OH Reaction on Full-Dimensional Accurate Potential Energy Surface

The hydrogen abstraction reaction of methanol with fluorine atoms can produce HF and CH₃O or CH₂OH radicals, which are im-portant in the environment, com-bustion, radiation, and interstellar chemistry. In this work, the dy-namics of this typical reaction is investigated by the quasi-classical trajectory method based on a re-cently developed globally accurate full-dimensional potential energy surface. Particularly, the vibra-tional state distributions of the polyatomic products CH₃O and CH2OH are determined by using the normal mode analysis method. It is found that CH₃O and CH₂OH are dom-inantly populated in the ground state when the reactants are at the ground ro-vibrational state. The OH stretching mode, torsional mode, H₂CO out-of-plane bending mode and their combination bands in the CH₂OH product can be effectively excited once the OH stretching mode of the reactant CH₃OH is excited to the first vibrationally excited state. Most of the available energy ows into the HF vibrational energy and the translational energy in both channels, while the radical products, CH₃O or CH₂OH, receive a small amount of energy, consistent with experiment, which is an indication of its spectator nature.