Li Xinyang, Mandal Arkajit, Huo Pengfei
Department of Chemistry, University of Rochester, Rochester, NY, USA.
The Institute of Optics, University of Rochester, Rochester, NY, USA.
Nat Commun. 2021 Feb 26;12(1):1315. doi: 10.1038/s41467-021-21610-9.
Recent experiments demonstrate the control of chemical reactivities by coupling molecules inside an optical microcavity. In contrast, transition state theory predicts no change of the reaction barrier height during this process. Here, we present a theoretical explanation of the cavity modification of the ground state reactivity in the vibrational strong coupling (VSC) regime in polariton chemistry. Our theoretical results suggest that the VSC kinetics modification is originated from the non-Markovian dynamics of the cavity radiation mode that couples to the molecule, leading to the dynamical caging effect of the reaction coordinate and the suppression of reaction rate constant for a specific range of photon frequency close to the barrier frequency. We use a simple analytical non-Markovian rate theory to describe a single molecular system coupled to a cavity mode. We demonstrate the accuracy of the rate theory by performing direct numerical calculations of the transmission coefficients with the same model of the molecule-cavity hybrid system. Our simulations and analytical theory provide a plausible explanation of the photon frequency dependent modification of the chemical reactivities in the VSC polariton chemistry.
近期实验表明，通过耦合光学微腔内的分子可以控制化学反应活性。相比之下，过渡态理论预测在此过程中反应势垒高度不会发生变化。在此，我们给出了极化激元化学中振动强耦合（VSC） regime下基态反应活性的腔修饰的理论解释。我们的理论结果表明，VSC动力学修饰源于与分子耦合的腔辐射模式的非马尔可夫动力学，导致反应坐标的动态笼效应以及在接近势垒频率的特定光子频率范围内反应速率常数的抑制。我们使用一种简单的解析非马尔可夫速率理论来描述与腔模式耦合的单分子系统。我们通过对分子 - 腔混合系统的相同模型进行透射系数的直接数值计算，证明了速率理论的准确性。我们的模拟和解析理论为VSC极化激元化学中化学反应活性的光子频率依赖性修饰提供了合理的解释。
