Department of Chemistry, Columbia University, 3000 Broadway, New York, NY, 10027, USA.
Nat Commun. 2023 May 12;14(1):2733. doi: 10.1038/s41467-023-38368-x.
Recent experiments suggest that ground state chemical reactivity can be modified when placing molecular systems inside infrared cavities where molecular vibrations are strongly coupled to electromagnetic radiation. This phenomenon lacks a firm theoretical explanation. Here, we employ an exact quantum dynamics approach to investigate a model of cavity-modified chemical reactions in the condensed phase. The model contains the coupling of the reaction coordinate to a generic solvent, cavity coupling to either the reaction coordinate or a non-reactive mode, and the coupling of the cavity to lossy modes. Thus, many of the most important features needed for realistic modeling of the cavity modification of chemical reactions are included. We find that when a molecule is coupled to an optical cavity it is essential to treat the problem quantum mechanically to obtain a quantitative account of alterations to reactivity. We find sizable and sharp changes in the rate constant that are associated with quantum mechanical state splittings and resonances. The features that emerge from our simulations are closer to those observed in experiments than are previous calculations, even for realistically small values of coupling and cavity loss. This work highlights the importance of a fully quantum treatment of vibrational polariton chemistry.
最近的实验表明，当将分子系统置于其中分子振动与电磁辐射强烈耦合的红外腔中时，可以改变基态化学反应性。这种现象缺乏坚实的理论解释。在这里，我们采用精确的量子动力学方法来研究凝聚相中腔修正化学反应的模型。该模型包含反应坐标与通用溶剂的耦合、腔与反应坐标或非反应模式的耦合以及腔与耗散模式的耦合。因此，包括了对化学反应腔修正进行现实建模所需的许多最重要的特征。我们发现，当分子与光腔耦合时，必须从量子力学的角度来处理这个问题，以获得对反应性变化的定量描述。我们发现，速率常数会发生相当大且明显的变化，这与量子力学态分裂和共振有关。与之前的计算相比，我们的模拟所呈现的特征更接近实验观察到的特征，即使是对于耦合和腔损耗的实际小值也是如此。这项工作强调了对振动极化子化学进行全量子处理的重要性。
