Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 101: Molecular Films: Electronics, Photovoltaics and Structure
O 101.8: Vortrag
Freitag, 4. April 2014, 12:15–12:30, WIL A317
Coupling of Brominated Tetrathienoanthracene on Crystalline Copper and Silver — •Rico Gutzler1,2,3, Luis Cardenas1,2, Josh Lipton-Duffin1, Dmitrii F. Perepichka2, and Federico Rosei1 — 1Institut National de la Recherche Scientifique, Université du Québec, 1650 boulevard Lionel-Boulet, Varennes, QC J3X 1S2, Canada — 2Department of Chemistry, McGill University, 801 Sherbrooke Str. West, Montreal, QC H3A 0B8, Canada — 3Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
We report the synthesis of extended 2D organic networks on copper and silver from thiophene-based molecules. A combination of STM and XPS yields insight into the reaction pathways from single molecules towards the formation of two-dimensional organometallic and polymeric structures via Ullmann reaction dehalogenation and C-C coupling. The thermal stability of the molecular networks is probed by annealing to temperatures of up to 500 °C. On Cu(111) only organometallic structures are formed, while on Ag(111) both organometallic and covalent polymeric networks were found to coexist. The ratio between organometallic and covalent bonds could be controlled by means of the annealing temperature. The thiophene moieties start degrading at 200 °C on the copper surface, whereas on silver the degradation process becomes significant only at 400 °C. Our work reveals how the interplay of a specific surface type and temperature steers the formation of organometallic and polymeric networks and describes how these factors influence the structural integrity of two-dimensional organic networks.