Density-functional theory study of enantioselective adsorption at chiral surfaces

COLL 541

Zeljko Sljivancanin, IRRMA, EPFL, PPH Ecublens, 1015 Lausanne, Switzerland, Kurt V. Gothelf, Center for Catalysis, and Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, Denmark, 8000 Aarhus C, Denmark, and Bjork Hammer, Institute of Physics and Astronomy, and Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, Denmark, 8000 Aarhus C, Denmark.

Density functional theory calculations are carried out for the adsorption of a chiral molecule, (S)- and (R)-HSCH2CHNH2CH2P(CH3)2, on a chiral surface, Au(17 11 9)S. The S-enantiomer is found to bind more strongly than the R-enantiomer by 8.8 kJ/mol, evidencing that the chiral nature of the kink sites at the Au(17 11 9) surface leads to enantioselective binding. The results of the density functional calculations are broken down into a local binding model in which each of the chiral molecule's three contact points with the surface provide a contribution to the overall adsorption bond strength. The enantioselective binding is demonstrated to originate from the simultaneous optimization of these three local bonds.

 

Chiral Surfaces

Division of Colloid and Surface Chemistry
The 225th ACS National Meeting, New Orleans, LA, March 23-27, 2003