Szabó István, Czakó Gábor
Department of Physical Chemistry and Materials Science, Institute of Chemistry, University of Szeged , Rerrich Béla tér 1, Szeged H-6720, Hungary.
J Phys Chem A. 2017 Nov 30;121(47):9005-9019. doi: 10.1021/acs.jpca.7b08140. Epub 2017 Oct 23.
We describe a novel theoretical approach to the bimolecular nucleophilic substitution (S2) reactions that is based on analytical potential energy surfaces (PESs) obtained by fitting a few tens of thousands high-level ab initio energy points. These PESs allow computing millions of quasi-classical trajectories thereby providing unprecedented statistical accuracy for S2 reactions, as well as performing high-dimensional quantum dynamics computations. We developed full-dimensional ab initio PESs for the F + CHY [Y = F, Cl, I] systems, which describe the direct and indirect, complex-forming Walden-inversion, the frontside attack, and the new double-inversion pathways as well as the proton-transfer channels. Reaction dynamics simulations on the new PESs revealed (a) a novel double-inversion S2 mechanism, (b) frontside complex formation,
我们描述了一种用于双分子亲核取代（S2）反应的新颖理论方法，该方法基于通过拟合数万个高水平从头算能量点获得的解析势能面（PES）。这些PES允许计算数百万条准经典轨迹，从而为S2反应提供前所未有的统计精度，以及进行高维量子动力学计算。我们为F + CHY [Y = F、Cl、I] 体系开发了全维从头算PES，其描述了直接和间接的、形成复合物的瓦尔登反转、前侧进攻以及新的双反转途径以及质子转移通道。在新的PES上进行的反应动力学模拟揭示了（a）一种新颖的双反转S2机制，（b）前侧复合物的形成，
