Parts | Days | Selection | Search | Downloads | Help
O: Oberflächenphysik
O 14: Postersitzung (Adsorption an Oberflächen, Epitaxie und Wachstum, Organische Dünnschichten, Oxide und Isolatoren, Phasenübergänge, Rastersondentechniken, Struktur und Dynamik reiner Oberflächen)
O 14.53: Poster
Monday, March 8, 2004, 18:00–21:00, Bereich C
Chiral adenine rows on Cu(110) – a theoretical contribution — •Martin Preuß, Wolf G. Schmidt, and Friedhelm Bechstedt — Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
The adsorption of adenine on copper allows for studying the concepts of self-assembly, adsorbate-induced chirality and low-dimensionality. Both LEED and STM [1] reveal a long-range ordering of adenine on Cu(110) in one-dimensional chains in the ±a1→+a2→ direction. The sign depends on the way of adsorption: mediated by the substrate, the formerly prochiral adenine molecules lose their mirror-plane symmetry and, after dimerization, form chiral chains. We study the process of adenine adsorption on Cu(110) in detail by means of a first principles approach. The calculations are carried out in the framework of density-functional theory using PAW potentials in the generalized gradient approximation. Possible molecular dimer chain models are presented and interpreted in terms of stability and chemistry. We especially address the problem of discrimination between different geometries and the bonding mechanism of adenine to the substrate.
[1] Q. Chen, D. J. Frankel, N. V. Richardson, Langmuir 2002, 18, 3219