Berlin 2005 – wissenschaftliches Programm
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O: Oberflächenphysik
O 32: Nanostrukturen III
O 32.7: Vortrag
Montag, 7. März 2005, 12:15–12:30, TU EB202
Building Planar Molecular Networks by Polymerization — •Markus Wahl1, Meike Stöhr1, Thomas A. Jung1,2, Hans-Joachim Güntherodt1, and Lutz H. Gade3 — 1Institute of Physics University of Basel, Switzerland — 2Paul-Scherrer-Institut, Villigen, Switzerland — 3Institute of Anorganic Chemistry University of Heidelberg, Germany
Self-assembly of molecules on surfaces directed by different supramolecular interactions has been widely explored. Our aim is the formation of covalently linked planar structures by means of polymerization confined in one or two dimensions.
Recent experiments with a perylene derivative (DPDI) using differential thermoanalysis and gravimetry demonstrated that bulk DPDI can polymerize releasing ammonia. Inspired by this observation, we formed covalent networks on metallic surfaces and checked the feasibility of such an approach for the formation of other stable polymer-nanostructures.
For this purpose, thin films of DPDI were prepared on Cu(111) by evaporation in a UHV setup. The molecular arrangements were analyzed with a home-built STM. For a coverage of 1ML DPDI a 1D polymer chain pattern was observed after annealing the sample to 580K. For lower coverage in the range of 0.3 ML only a mobile phase was detected before annealing. However, upon annealing a stable 2D network with a honeycomb-like structure was observed which conveniently matches the angles and distances expected for the chemically feasible polymer structure.