Berlin 2008 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 51: Metal Substrates: Adsorption of Organic/Bio Molecules III
O 51.5: Vortrag
Mittwoch, 27. Februar 2008, 16:15–16:30, MA 041
Thermally induced polymerization of molecules on surfaces — •Manfred Matena1, Jorge Lobo-Checa1, Meike Stöhr1, Kathrin Müller2, Thomas A. Jung2, Till Riehm3, and Lutz H. Gade3 — 1Departement Physik, Universität Basel, Switzerland — 2Paul-Scherrer-Institut, Villigen, Switzerland — 3Institut für Anorganische Chemie, Universität Heidelberg, Germany
By utilizing the concepts of supramolecular chemistry, impressive results for molecular self-assembly on surfaces have been presented. Mostly, non-covalent interactions like metal coordination, hydrogen bonding or dipolar coupling are exploited to create extended supramolecular patterns in variable dimensions. One common approach to influencing these structures relies mainly on the sophisticated design of the molecular functional groups. Thus it makes use of properties already inherent to the molecules. In our work we have chosen a different concept. A thermally-induced surface-assisted reaction was used to modify the endgroups of a perylene derivative (TAPP) and thereby, the molecular interactions are altered.
TAPP was found to form a closed-packed assembly on Cu(111), whereas the intermolecular interactions are based upon vdW-forces. After annealing at 150°C, a metal coordinated rectangular network is obtained which is commensurate to the underlying Cu surface. In this case the organic molecules coordinate to Cu atoms through the lone pairs of their nitrogen atoms. A second annealing step at temperatures >240°C modifies the molecule on the surface and leads to covalently linked polyaromatic chains.