Enantiospecific Adsorption of (R)-3-Methylcyclohexanone on Naturally Chiral Cu(531) R&S Surfaces

Abstract

The enantiospecific adsorption and desorption of (R)-3-methylcyclohexanone on naturally chiral Cu(531)R&S surfaces was studied using temperature programmed desorption. The Cu(531)R&S surfaces are of interest because they lie at the center of the stereographic triangle and thus, have the highest density of chiral adsorption sites possible on the surface of a face centered cubic metal. Several (R)-3-methylcyclohexanone desorption features were resolved in the TPD spectra from Cu(531)R&S surfaces and were assigned to desorption of molecules from terrace, step, and kink sites. The peaks associated with (R)-3-methylcyclohexanone desorbing from the R- and S-kink sites differed in temperature by 2.2 ± 0.6 K. This corresponds to an enantiospecific difference in the desorption energies of 0.5 ± 0.2 kJ/mol, with a preference for adsorption of (R)-3-methylcyclohexanone at the S-kinks on the Cu(531)S surface.