论文标题
使用外部时间依赖性调整对称势能表面上的分支比
Tuning the Branching Ratio in a Symmetric Potential Energy Surface with a Post-Transition State Bifurcation using External Time Dependence
论文作者
论文摘要
通过分支比例量化的化学选择性是与许多有机化学反应有关的现象。它可以在势能表面上表现出，该势能表面具有两个顺序索引-1鞍座之间该区域的山谷 - ridge拐点，其中一个鞍座具有比另一个鞍座更高的能量。当轨迹越过较高能量马鞍（入口通道）并接近较低能量鞍座的区域时，会发生反应。在较低的能量马鞍的两侧，我们在这项工作中要解决的问题是，鉴于最初的轨迹集合，进入每个井的轨迹的相对分数是多少。对于对称PES，此部分为1：1。我们考虑一种以幅度，频率和相为特征的时间周期性强迫对称的PE。在这封信中，我们分析了分支比率如何取决于这三个参数。
Chemical selectivity, as quantified by a branching ratio, is a phenomenon relevant for many organic chemical reactions. It may be exhibited on a potential energy surface that features a valley-ridge inflection point in the region between two sequential index-1 saddles, with one saddle having higher energy than the other. Reaction occurs when a trajectory crosses the region of the higher energy saddle (the entrance channel) and approaches the lower energy saddle. On both sides of the lower energy saddle, there are two wells and the question we address in this work is that, given an initial ensemble of trajectories, what is the relative fraction of trajectories that enter each well. For a symmetric PES this fraction is 1:1. We consider a symmetric PES subjected to a time-periodic forcing characterized by an amplitude, frequency, and phase. In this letter we analyse how the branching ratio depends on these three parameters.
