AVS 51st International Symposium
    Surface Science Tuesday Sessions
       Session SS1-TuA

Paper SS1-TuA4
Enantioselective Reactivity of R-2-bromobutane on Chiral Copper Surfaces

Tuesday, November 16, 2004, 2:20 pm, Room 210B

Session: Hydrocarbon Reactions on Metal Surfaces
Presenter: D.M. Rampulla, Carnegie Mellon University
Authors: D.M. Rampulla, Carnegie Mellon University
A.J. Gellman, Carnegie Mellon University
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Enantioselective reactions are integral to most biological chemistry and large-scale pharmaceutical production. Enantioselective reactions require chiral media such as solvents, surfaces, or catalysts of a single handedness. Enantioselective heterogeneous catalysis is a promising method for the preparation of chiral compounds but requires catalytic surfaces with inherently chiral structure. The stepped and kinked high Miller index surfaces of metals are naturally chiral and have been shown to interact enantiospecifically with chiral adsorbates. Enantioselective desorption of small chiral molecules from such surfaces has been demonstrated and studied, but enantioselective reactivity on naturally chiral metal surfaces has not been explored. Temperature Programmed Reaction Spectroscopy (TPRS) has been used to study the decomposition of R-2-bromobutane on the chiral Cu(643)@super R@ and Cu(643)@super S@ surfaces. Alkyl halides, such as R-2-bromobutane adsorb dissociatively to form R-2-butyl groups, which decompose via @beta@-hydride elimination to yield 1- and 2-butenes. The temperatures at which these desorb and the selectivity to 1- and 2-butenes are influenced by the chirality of the copper surfaces. Earlier results of R-2-bromobutane on Cu(531)@super R&S@ surfaces will be discussed and compared with more recent results obtained on the Cu(643)@super R&S@ surfaces.