AVS 52nd International Symposium
    Surface Science Monday Sessions
       Session SS-MoP

Paper SS-MoP5
Adsorption Geometries of Prochiral Molecules on Pt(111): Heterogeneous Enantioselective Hydrogenation

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Surface Science Poster Session
Presenter: M.A. Laliberté, Université Laval, Canada
Authors: M.A. Laliberté, Université Laval, Canada
A. Rouffignat, Université Laval, Canada
I. Temprano, Université Laval, Canada
S. Lavoie, Université Laval, Canada
P.H. McBreen, Université Laval, Canada
Correspondent: Click to Email
HREELS and RAIRS were used study the adsorption of carbonyls and dicarbonyls on Pt(111) with the goal of better understanding the Orito reaction. The Orito reaction describes the enantioselective hydrogenation of the keto-function of alpha-ketoesters on chiral-modified platinum particles. Measurements were performed on acetone, ethyl formate,biacetyl, methyl pyruvate and ethyl pyruvate adsorbed on clean Pt(111), and coadsorbed with toluene, benzene, naphthalene, methyl naphthylene, cyclohexane and naphthylethylamine. Very strong coadsorption interactions resulting in complete modification of the adsorption geometries of the carbonyl molecules were observed for several of these systems. The results aid in mapping out the range of adsorption geometries available to dicarbonyl substrates in the Orito reaction. The results will be discussed in the context of a proposed new mechanism for the enantioselective reaction.