Dresden 2006 – wissenschaftliches Programm
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O: Oberflächenphysik
O 9: Organic films I
O 9.7: Vortrag
Montag, 27. März 2006, 16:30–16:45, TRE Phys
Coverage dependent structure of 2D networks formed by oligopyridines on Ag(111)/Ru(0001) Bonds — •Achim Breitruck1, Matthias Roos1, Christoph Meier2, Ulrich Ziener2, Mona Seyfried1, Harry E. Hoster1, and Rolf J. Behm1 — 1Department Surface Chemistry and Catalysis, University of Ulm, 89069 Ulm — 2Department Macromolecular Chemistry and Organic Materials, University of Ulm, 89081 Ulm
Oligopyridines form highly ordered 2D networks on a number of single crystal surfaces [1]. They are of interest both for the physical background of their structure formation itself and for their possible utilization as self assembling templates for nanostructuring. In the present study, layers of increasing coverage have been vapor deposited in UHV onto Ag(111)-like adlayers on Ru(0001). STM analyses reveal at least 5 different highly ordered structures, with a geometry depending on the coverage and, in some cases, the temperature during and after deposition. The coverage dependence is an immediate consequence of the geometry of the utilized oligopyridines, which at higher packing densities forces the molecules into local constellations with less network stabilizing hydrogen bonds per molecule. This also involves a coverage dependent adsorption energy, which allows to savely transform one structure into another by partial desorption of the adlayer.
[1] U. Ziener, J.-M. Lehn, A. Morran, M. Möller, Chem. Eur. J., 2002, 8(4), 951-957