论文标题
支持分子开关中的多维氢隧穿：表面相互作用的作用
Multidimensional Hydrogen Tunneling in Supported Molecular Switches: The Role of Surface Interactions
论文作者
论文摘要
在受支持的分子开关结构中氢转移反应的核隧道交叉温度（$ T_C $）可能位于室温附近。这要求将核量子效应（NQE）纳入反应速率，即使在高温下也是如此。但是，NQE的标准计算依赖于参数化的降低模型，在这些环境中迅速变得不足。在这封信中，我们研究了基于卟啉分子的范式分子开关，这些分子吸附在金属表面上的全维计算，这些计算将电子的密度功能理论与半经典环形聚合物的密度功能理论结合在一起，并将其与核的半经典环形聚合物Instanton近似结合在一起。我们表明，由于深度隧道状态的表面波动，可以通过数量级来提高双分子内氢转移（DHT）速率。我们还解释了低于$ t_c $的速率的Arrhenius温度依赖性的起源，以及为什么这种依赖性在不同表面上有所不同。我们提出了一个简单的模型，以合理化跨越不同FCC [110]表面的DHT速率的温度依赖性。
The nuclear tunneling crossover temperature ($T_c$) of hydrogen transfer reactions in supported molecular-switch architectures can lie close to room temperature. This calls for the inclusion of nuclear quantum effects (NQE) in the calculation of reaction rates even at high temperatures. However, standard computations of NQE relying on parametrized dimensionality-reduced models, quickly become inadequate in these environments. In this letter, we study the paradigmatic molecular switch based on porphycene molecules adsorbed on metallic surfaces with full-dimensional calculations that combine density-functional theory for the electrons with the semi-classical ring-polymer instanton approximation for the nuclei. We show that the double intramolecular hydrogen transfer (DHT) rate can be enhanced by orders of magnitude due to surface fluctuations in the deep tunneling regime. We also explain the origin of an Arrhenius temperature-dependence of the rate below $T_c$ and why this dependence differs at different surfaces. We propose a simple model to rationalize the temperature dependence of DHT rates spanning diverse fcc [110] surfaces.
