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O: Fachverband Oberflächenphysik

O 30: Metal substrates: Adsorption of organic / bio molecules IV

O 30.3: Vortrag

Mittwoch, 25. März 2009, 11:00–11:15, SCH A118

Covalent interlinking on the surface by condensation polymerization of p-phenylenediamine and terephthaloyl chloride — •Christoph H. Schmitz, Julian Ikonomov, and Moritz Sokolowski — Inst. f. Physikal. u. Theoret. Chemie, Universität Bonn

Long-range ordered structures of organic adsorbates on metal surfaces are mainly based on weak adsorbate-adsorbate interactions, such as van der Waals-forces, dipole interactions and hydrogen bonds. Technical applications require more robust and durable layers, that may be realized by covalent networks. Examples of the direct covalent interlinking of small organic molecules on the surface are scarce [1-3] and the reactions are mainly induced by heating, which limits the range of possible substances. We herein report on the formation of covalently interlinked structures of a polyamide via condensation polymerization directly on the surface. The vapour-deposition polymerization (VDP) technique was combined with ultra-high vacuum preparations methods to obtain polymer monolayers. We demonstrate this concept by the reaction of p-phenylenediamine (PPD) and terephthaloyl chloride (TPC) to form poly(p-phenylene terephthalamide) (PPTA) on the Ag(111) surface at room-temperature. After removal of the excess monomer, the polyamide chains arrange in long-range ordered islands on the surface. The structures have been characterized by variable temperature scanning tunneling microscopy (VT-STM). (Funded by DFG through SFB 624) [1] L. Grill et al., Nature Nanotech. 2007, 2, 687. [2] N. A. A. Zwaneveld et al., J. Am. Chem. Soc. 2008, 130, 6678. [3] S. Weigelt et al., Angew. Chem. 2008, 120, 4478.