Mauguière Frédéric A L, Collins Peter, Kramer Zeb C, Carpenter Barry K, Ezra Gregory S, Farantos Stavros C, Wiggins Stephen
School of Mathematics, University of Bristol , Bristol BS8 1TW, United Kingdom.
Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853, United States.
J Phys Chem Lett. 2015 Oct 15;6(20):4123-8. doi: 10.1021/acs.jpclett.5b01930. Epub 2015 Oct 5.
We re-examine the prototypical roaming reaction--hydrogen atom roaming in formaldehyde decomposition--from a phase space perspective. Specifically, we address the question "why do trajectories roam, rather than dissociate through the radical channel?" We describe and compute the phase space structures that define and control all possible reactive events for this reaction, as well as provide a dynamically exact description of the roaming region in phase space. Using these phase space constructs, we show that in the roaming region, there is an unstable periodic orbit whose stable and unstable manifolds define a conduit that both encompasses all roaming trajectories exiting the formaldehyde well and shepherds them toward the H2···CO well.
我们从相空间的角度重新审视典型的漫游反应——甲醛分解中的氢原子漫游。具体而言，我们探讨“为什么轨迹会漫游，而不是通过自由基通道解离？”这一问题。我们描述并计算了定义和控制该反应所有可能反应事件的相空间结构，同时给出了相空间中漫游区域的动态精确描述。利用这些相空间结构，我们表明在漫游区域存在一个不稳定的周期轨道，其稳定和不稳定流形定义了一个管道，该管道既包含了所有离开甲醛阱的漫游轨迹，又将它们引向H2···CO阱。
