美国埃默里大学Joel M. Bowman课题组的最新研究利用基于团簇模型的准经典模拟，探明了吸附在NaCl上的CO异构化过程中振动促进的漫游行为。2021年1月18日出版的《自然-化学》杂志发表了这项最新研究成果。

出于想要了解异构化的量子本质，近年来有一些实验观测研究了OC-NaCl(100)向CO-NaCl(100)转变时振动诱导的异构化。为了研究这一异构化过程的机理，研究人员用有限(CO–NaCl)n团簇模型进行了动力学计算。研究人员使用高水平从头算数据建立了CO-NaCl和CO-CO相互作用的新的势能面，并报道了纯CO-NaCl势能面的关键特征，这些特征与实验数据大体一致。

研究人员又通过使用几种团簇模型研究了异构化过程的动力学。他们发现，在所有模型中，异构化都在高度活化的CO振动态中出现，这也与实验观测是吻合的。对反应路线轨迹的详细研究表明，当CO和NaCl的距离比传统的异构化鞍点时的距离长时，异构化才会发生，这强烈暗示着一种“漫游”行为的存在。

附：英文原文

Title: Quasiclassical simulations based on cluster models reveal vibration-facilitated roaming in the isomerization of CO adsorbed on NaCl

Author: Apurba Nandi, Peng Zhang, Jun Chen, Hua Guo, Joel M. Bowman

Issue&Volume: 2021-01-18

Abstract: The desire to better understand the quantum nature of isomerization led to recent experimental observations of the vibrationally induced isomerization of OC–NaCl(100) to CO–NaCl(100). To investigate the mechanism of this isomerization, we performed dynamics calculations using finite (CO–NaCl)n cluster models. We constructed new potential energy surfaces for CO–NaCl and CO–CO interactions using high-level ab initio data and report key properties of the bare CO–NaCl potential energy surface, which show much in common with the experiment. We investigated the isomerization dynamics using several cluster models and, in all cases, isomerization was seen for highly excited CO vibrational states, in agreement with experiments. A detailed examination of the reaction trajectories indicates that isomerization occurs when the distance between CO and NaCl is larger than the distance at the conventional isomerization saddle point, which is a strong indicator of ‘roaming’.

DOI: 10.1038/s41557-020-00612-y

Source: https://www.nature.com/articles/s41557-020-00612-y