First-Principles Studies of Chiral Adsorption on Metal Surfaces

David Sholl

Department of Chemical Engineering Carnegie Mellon University, United States

Density functional theory (DFT) calculations are a useful complement to experimental methods for understanding the chemisorption of molecules on well defined metal surfaces. I will present DFT calculations that have probed several aspects of chiral adsorption on metal surfaces. First, I will discuss the structure of enantiopure and racemic alanine adlayers adsorbed on Cu(100) and Cu(110). A good deal is known about these adlayers, but several important features related to their chiral behavior have been clarified using DFT calculations. We have also used DFT to understand the structure of alanine on Cu(3,1,17), an intrinsically chiral surface. These calculations provide detailed information on the experimentally observed reconstruction of Cu(100) by adsorbed alanine that leads to creation of chiral facets of Cu(3,1,17). Second, we have used DFT to examine a range of small chiral molecules adsorbing on a range of intrinsically chiral Cu surface. The outcomes from these calculations allow several hypotheses regarding the enantiospecificity of chemisorption on these surfaces to be tested and give suggestions for selecting adsorbate/surface combinations that will have highly enantiospecific adsorption. Finally, I will show how DFT calculations have been used to examine strategies for tuning the chemical functionality of chiral metal surfaces by doping these surfaces with low coverages of additive metals.