Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Nanoscale Materials Science , CH-8600 Dübendorf, Switzerland.
Physics and Materials Science Research Unit, University of Luxembourg , 1511 Luxembourg, Luxembourg.
J Am Chem Soc. 2018 Jan 31;140(4):1401-1408. doi: 10.1021/jacs.7b10980. Epub 2018 Jan 19.
We unravel the origin of the recently observed striking enantioselectivity of the PdGa(111) surface with respect to the adsorption of a small organic molecule, 9-ethynylphenanthrene, using first-principles calculations. It turns out that the key ingredient to understand the experimental evidence is the appropriate description of van der Waals interactions beyond the widely employed atomic pairwise approximation. A recently developed van der Waals-inclusive density functional method, which encompasses dielectric screening effects, reveals the origin of the experimentally observed enantioselectivity and provides conclusive evidence of chiral recognition on a bimetallic surface driven by dispersion interactions. The incorporation of dielectric screening leads to a renormalization of the dispersion interaction range, allowing for the appropriate weighting of the molecule-substrate interactions at intermediate distances between 2.5 and 5 Å. Our findings have implications for the structure and stability of complex organic/inorganic systems where dielectric screening effects are expected to be of general importance.
我们使用第一性原理计算方法揭示了 PdGa(111) 表面对小分子 9-乙炔基菲的吸附具有最近观察到的显著对映选择性的起源。事实证明，理解实验证据的关键因素是对范德华相互作用的适当描述，而不仅仅是广泛采用的原子对近似。最近开发的一种包含范德华相互作用的密度泛函方法，包括介电屏蔽效应，揭示了实验观察到的对映选择性的起源，并提供了由分散相互作用驱动的双金属表面手性识别的确凿证据。介电屏蔽的引入导致了分散相互作用范围的重整化，从而可以在 2.5 和 5 Å 之间的中间距离处对分子-底物相互作用进行适当加权。我们的发现对于复杂的有机/无机系统的结构和稳定性具有重要意义，预计介电屏蔽效应在这些系统中具有普遍重要性。
