AVS 62nd International Symposium & Exhibition
    Surface Science Tuesday Sessions
       Session SS+EN-TuA

Paper SS+EN-TuA12
Single-Molecule and Single-Active-Site Studies of Stereocontrol by Chemisorbed Chiral Molecules

Tuesday, October 20, 2015, 6:00 pm, Room 112

Session: Photocatalysis, Photochemistry, and Chirality at Surfaces
Presenter: Peter McBreen, Laval University, Canada
Authors: P.H. McBreen, Laval University, Canada
Y. Dong, Laval University, Canada
J.C. Lemay, Laval University, Canada
G. Goubert, Laval University, Canada
M.N. Groves, Aarhus University, Denmark
B. Hammer, Aarhus University, Denmark
Correspondent: Click to Email
Isolated adsorbed chiral molecules can stereodirect prochiral co‐adsorbates on reactive metal surfaces and the application of this phenomenon underpins a method to perform asymmetric heterogeneous catalytic reactions. Typically, the stereochemical action is attributed to intermolecular interactions in complexes formed by docking the prochiral substrate in a chiral pocket created by the chemisorbed chiral molecule. We will present results from combined variable temperature STM and optB88-vdW DFT studies of individual bimolecular docking complexes formed by enantiopure 1-(1-naphthyl)ethylamine and selected prochiral molecules on Pt(111). The experiments reveal sub-molecularly resolved and time-resolved site-specific and stereospecific data. The results show that a single chemisorbed enanantiomer simultaneously presents several chiral pockets, each displaying a specific prochiral ratio for a given substrate molecule. A hierarchy of metal-molecule and molecule-molecule interactions is found to control prochiral selection at each site. Time-lapsed STM measurements of individual substrate molecules sampling a set of chiral pockets provide new insight on the dynamics of stereocontrol.