Kinetics and Dynamics of Adsorption and Desorption on Chiral Surfaces

在过去的几十年里，人们对在表现出微观手性的表面上进行不对称化学的前景非常感兴趣，这要么是由于其固有的晶体结构，要么是由于涉及手性分子的修饰。在很大程度上，研究的重点是阐明这类系统的平衡结构和能量学，只是推断动力学和动力学的可能结果，而不是直接解决这些问题。然而，最近有报道了一些旨在揭示不对称动力学效应的实验(例如，在爆炸解吸中)，而且利用超声波分子束来研究不对称吸附动力学似乎也有相当大的前景。第一原理分子动力学的应用将使我们能够确认在一系列候选体系的吸附和解吸过程中手性效应的存在(并评估其大小)。首先，我们将关注本征手性铜{531}表面，它结合了高密度的手性扭结中心和相对较低的反应性，适合于结合相对微妙的手性分子而不解离成非手性产物。探针分子可能既包括手性物种，也包括非手性物种，如有机酸和相关化合物。希望这项工作将促进这一令人兴奋的领域的实验工作。

There has been considerable interest, over the past couple of decades, in the prospects for asymmetric chemistry conducted at surfaces that exhibit microscopic chirality, either due to their inherent crystalline structure or conferred by modification involving chiral molecules. For the most part, investigations have focussed upon elucidation of the equilibrium structure and energetics of such systems, merely inferring likely consequences for dynamics and kinetics rather than addressing them directly. Recently, however, experiments designed to reveal asymmetric kinetic effects (for example, in explosive desorption) have been reported, and there would seem also to be some considerable promise in making use of supersonic molecular beams to study the dynamics of asymmetric adsorption.The present project aims to explore this same territory from a computational perspective. Application of first-principles molecular dynamics will allow usto confirm the existence of (and assess the magnitude of) chiral effects in both adsorption and desorption processes for a range of candidate systems. Initially, we will focus upon the intrinsically chiral Cu{531} surface, which combines a high density of chiral kink sites with a relatively low reactivity suitable for binding comparatively delicate chiral molecules without dissociation into achiral products. Probe molecules will likely include both chiral and achiral species, such as organic acids and related compounds. It is hoped that the work will stimulate experimental work in this exciting area.