Final Report Summary - ENREMOS (Enantioselective Reactions on Model Chirally Modified Surfaces)
Imparting chirality to non-chiral metal surfaces by adsorption of chiral modifiers is a highly promising route to create effective heterogeneously catalyzed processes for production of enantiopure pharmaceuticals. A molecular-level understanding of enantioselective processes on chiral surfaces is an importance prerequisite for the rational design of new enantiospecific catalysts, which is currently nearly missing. In the present project, we addressed this topic from the viewpoint of surface science and obtained the fundamental level understanding of the structure of chirally modified surfaces, the bonding of the prochiral substrate on the pristine and chirally-modified metal surfaces and the reactivity behavior toward hydrogenation. We applied a combination of the molecular beam techniques, infrared spectroscopy, scanning tunneling microscopy and single crystal adsorption calorimetry to obtain a full mechanistic picture of these aspects. The reactive processes on chiral surfaces were carried out on the extended single crystal surfaces, mimicking a local interaction of the modifier-substrate complexes with a metal, while some of the aspects were also investigated the small metal nanoparticles that more accurately resemble the structural properties and high catalytic activity of practically relevant powdered supported catalyst. Obtained results reveal a great importance of the intermolecular interactions in heterogeneously catalyzed processes, which might turn the surface highly chemo- and/or enantioselective towards desired reaction route.