AVS 53rd International Symposium
    Surface Science Monday Sessions
       Session SS1-MoM

Paper SS1-MoM9
Chiral Surface Structure and Enantioselectivity

Monday, November 13, 2006, 10:40 am, Room 2002

Session: Catalytic Chemistry of Hydrocarbons
Presenter: A.J. Gellman, Carnegie Mellon University
Authors: A.J. Gellman, Carnegie Mellon University
J.D. Horvath, Milliken Corp.
Y. Huang, Carnegie Mellon University
A. Koritnik, University of Michigan
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High Miller index metal surfaces with structures lacking mirror symmetry are naturally chiral and have enantiospecific interactions with chiral adsorbates. This set of surfaces spans the interior of the stereographic projection of surface structures. In the case of fcc lattices the chiral surfaces are those that have kink-step-terrace structures. The adsorption of R-3-methylcyclohexanone is enantiospecific in the sense that its desorption energies from the chiral kinks are dependent on the handedness of the kink. The kinks, steps and terraces on the high Miller index surfaces are formed by the (100), (110) and (111) microfacets. Thus there are, in principle, only six types of kinked surfaces dictated by which of the three microfacets forms the kink, step and terrace. R-3-methylcyclohexnanone adsorption and temperature programmed desorption has been studied on a set of 9 achiral Cu surfaces and on both the R- and S-enantiomers of a set of 7 chiral Cu surfaces. Six of the chiral surfaces have been chosen to fall within the six zones of the stereographic projection having surface structures formed of the six combinations of kink, step and terrace formed by (100), (110) and (111) microfacets. The desorption spectra of R-3-methylcyclohexanone can be resolved into components arising from desorption from the kinks, the step edges and form the terraces of each of the surfaces. The desorption from the kink sites is enantiospecific in the sense that the R-3-methylcyclohexanone has different desorption energies from the two enantiomers of the surfaces. The enantiospecificity of the desorption energies varies from @DELTA@@DELTA@E@sub des@ = 0.2 to 1.0 kJ/mole.