Abstract
The adsorption of (S)-lysine onto submonolayer coverages of Ni on Au{111} was investigated by scanning tunnelling microscopy and reflection absorption infrared spectroscopy. Arrays of two-dimensional Ni nanoclusters were prepared on the Au{111} surface. The sticking probability of (S)-lysine was found to increase by an order of magnitude on Au surfaces templated by Ni compared to the clean Au surface. (S)-lysine corrodes Ni from the edges of clusters forming nickel lysinate complexes which self-assemble to form ordered molecular arrays. Below a threshold coverage, the Ni clusters are completely destroyed by (S)-lysine adsorption. Under these conditions, extensive restructuring of the Au steps is observed. The implications of our work for understanding the role of chiral modifiers in Ni catalysed enantioselective catalysis are discussed.
Highlights
Understanding the interaction of biological molecules such as amino acids with surfaces is of fundamental interest in areas such as the development of biosensors [1] and in the design of biocompatible materials [2]
The ability of the metal surface to allow the selective creation of one enantiomeric product is thought to be associated with the establishment of control over the adsorption geometry of the prochiral molecule such that one enantiotopic face of the reactant adsorbs on the surface in preference to the other allowing coadsorbed hydrogen atoms to attack the C_O bond from beneath the bond resulting in the formation of exclusively one type of chiral centre
It is widely believed that the adsorption of the chiral modifier provides a docking site for the pro-chiral reagent favouring the adsorption of one enantiotopic face [4]
Summary
Understanding the interaction of biological molecules such as amino acids with surfaces is of fundamental interest in areas such as the development of biosensors [1] and in the design of biocompatible materials [2]. Ni catalysts modified by the adsorption of amino acids from solution have been shown to be effective catalysts for the enantioselective hydrogenation of β-ketoesters [3]. The ability of the metal surface to allow the selective creation of one enantiomeric product is thought to be associated with the establishment of control over the adsorption geometry of the prochiral molecule such that one enantiotopic face of the reactant adsorbs on the surface in preference to the other allowing coadsorbed hydrogen atoms to attack the C_O bond from beneath the bond resulting in the formation of exclusively one type of chiral centre. At low Ni coverage, etching completely destroys the Ni clusters and significant restructuring of Ni steps is observed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
