Skip to main content
Article thumbnail
Location of Repository

Enantiospecific adsorption of alanine on the chiral Cu{531} surface

By M.J. Gladys, A.V. Stevens, N.R. Scott, G. Jones, D. Batchelor and Georg Held

Abstract

We have studied enantiospecific differences in the adsorption of (S)- and (R)-alanine on Cu{531}R using\ud low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy, and near edge X-ray absorption\ud fine structure (NEXAFS) spectroscopy. At saturation coverage, alanine adsorbs as alaninate forming a\ud p(1 4) superstructure. LEED shows a significantly higher degree of long-range order for the S than for the\ud R enantiomer. Also carbon K-edge NEXAFS spectra show differences between (S)- and (R)-alanine in the\ud variations of the ð resonance when the linear polarization vector is rotated within the surface plane. This\ud indicates differences in the local adsorption geometries of the molecules, most likely caused by the interaction\ud between the methyl group and the metal surface and/or intermolecular hydrogen bonds. Comparison with\ud model calculations and additional information from LEED and photoelectron spectroscopy suggest that both\ud enantiomers of alaninate adsorb in two different orientations associated with triangular adsorption sites on\ud {110} and {311} microfacets of the Cu{531} surface. The experimental data are ambiguous as to the exact\ud difference between the local geometries of the two enantiomers. In one of two models that fit the data equally\ud well, significantly more (R)-alaninate molecules are adsorbed on {110} sites than on {311} sites whereas for\ud (S)-alaninate the numbers are equal. The enantiospecific differences found in these experiments are much\ud more pronounced than those reported from other ultrahigh vacuum techniques applied to similar systems

Publisher: American Chemical Society
Year: 2007
OAI identifier: oai:centaur.reading.ac.uk:16621
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://dx.doi.org/10.1021/jp07... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.