Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, USA.
Molecules. 2022 Jan 24;27(3):754. doi: 10.3390/molecules27030754.
The O(P) + CH reaction plays an important role in hydrocarbon combustion. It has two primary competing channels: H + HCCO (ketenyl) and CO + CH (triplet methylene). To further understand the microscopic dynamic mechanism of this reaction, we report here a detailed quasi-classical trajectory study of the O(P) + CH reaction on the recently developed full-dimensional potential energy surface (PES). The entrance barrier TS1 is the rate-limiting barrier in the reaction. The translation of reactants can greatly promote reactivity, due to strong coupling with the reaction coordinate at TS1. The O(P) + CH reaction progress through a complex-forming mechanism, in which the intermediate HCCHO lives at least through the duration of a rotational period. The energy redistribution takes place during the creation of the long-lived high vibrationally (and rotationally) excited HCCHO in the reaction. The product energy partitioning of the two channels and CO vibrational distributions agree with experimental data, and the vibrational state distributions of all modes of products present a Boltzmann-like distribution.
O(P) + CH 反应在碳氢化合物燃烧中起着重要作用。它有两个主要的竞争通道：H + HCCO（烯酮基）和 CO + CH（三重态亚甲基）。为了进一步了解这个反应的微观动力学机制，我们在这里报告了一个关于最近开发的全维势能面（PES）上的 O(P) + CH 反应的详细准经典轨迹研究。入口障碍 TS1 是反应中的速率限制障碍。反应物的平移可以极大地促进反应性，这是由于与 TS1 上的反应坐标的强烈耦合。O(P) + CH 反应通过一种复杂形成机制进行，其中中间体 HCCHO 至少在一个旋转周期内存在。能量重新分配发生在反应中长寿命的高振动（和旋转）激发 HCCHO 的形成过程中。两个通道的产物能量分配和 CO 振动分布与实验数据一致，并且所有产物模式的振动态分布呈现出玻尔兹曼分布的特征。
