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O: Fachverband Oberflächenphysik

O 14: Metal substrates: Adsorption of organic / bio molecules II

O 14.11: Vortrag

Montag, 22. März 2010, 17:30–17:45, H36

2D-grids as precursors for 2D-crystals — •Thomas Waldmann, Christina Nenon, Robert Reichert, Harry E. Hoster, and R. Jürgen Behm — Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm, Germany

The bis(terpyridine) derivative 2,4’-BTP [1,2] forms ordered monolayers (ML) on Ag(111)/Ru(0001) [3-5], Au(111) [3,5], highly ordered pyrolytic graphite (HOPG) [1-3,5], and Ag(100) at coverages between 0.35 and 0.44 molecules/nm². At T = 300 K and lower coverage, the adsorbates form a two-dimensional (2D) admolecule gas, where they move faster than the STM-tip. At T = 115 K, one can observe (2,4’-BTP)_n oligomer chains stabilized by C-H^...N-type hydrogen bonds. We show that the local configurations of the molecules and their individual orientations with respect to the substrate are similar to those known from ordered structures formed by the molecules at higher coverages. This confirms our previous suggestion that the corrugation of the molecule-substrate potential and the molecule-molecule interactions play an equally important role for the structures formed by this kind of molecules [3-4].
[1] U. Ziener et al., Chem.Eur.J. 8, 2002, 951.
C. Meier et al., J.Phys.Chem.B 109, 2005, 21015.
H.E. Hoster et al., Langmuir 23, 2007, 11570.
M. Roos et al., Phys.Chem.Chem.Phys. 9, 2007, 5672.
M. Roos et al., Phys.Chem.Chem.Phys., DOI: 10.1039/b920481d