초록 |
The importance of enantioselective chemical processing for the production of pharmaceuticals arises from homochirality of life on Earth. When both enantiomers of chiral drugs are ingested by a living organism, the two enantiomers can show significantly different physiological impacts because of the homochirality. Developing a fundamental understanding of enantioselectivity of chiral molecules on the metal surfaces is essential for the rational design of enantioselective heterogeneous catalysts. In this talk, I address adsorption behaviors of chiral molecules on chiral and achiral Cu metal surfaces. On naturally chiral Cu surfaces, exposure of a racemic, gas phase mixture of D- and *L-aspartic acid leads to establishment of an enantiospecific adsorption equilibrium with an enantiomeric excess of ~40% in the adsorbed phase. Exposure of the achiral Cu{111} surface to non-racemic aspartic acid results in local amplification of enantiomeric excess on the surface via homochiral disproportionation. These two adsorption behaviors are generally active and should be considered in all enantioselective chemical processes occurring on metal surfaces. |