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

The enantiospecific adsorption and desorption of (R)-3-methylcyclohexanone on naturally chiral Cu(531) surfaces was studied using temperature programmed desorption. The Cu(531) 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) surfaces and were assigned to desorption of molecules from terrace, step, and kink sites. The peaks associated with (R)-3-methylcyclohexanone desorbing from the Rand 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) surface.