Berlin 2018 – wissenschaftliches Programm
O 5.8: Vortrag
Montag, 12. März 2018, 12:30–12:45, MA 042
On-Surface Synthesis of Heptacene and its Interaction with a Metal Surface — •Malte Zugermeier1, Manuel Gruber2, Martin Schmid1, Benedikt P. Klein1, Lukas Ruppenthal1, Philipp Müller1, Ralf Einholz3, Wolfgang Hieringer4, Richard Berndt2, Holger F. Bettinger3, and J. Michael Gottfried1 — 1Fachbereich Chemie, Philipps-Universität Marburg, Germany — 2Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Germany — 3Institut für Organische Chemie, Eberhard Karls Universität Tübingen, Germany — 4Lehrstuhl für Theoretische Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
Acenes are important molecular organic semiconductors, whose electronic properties scale with the length of the conjugated system. With increasing length, the HOMO-LUMO gap and the reorganization energy decrease, while the charge carrier mobility increases. These changes, which are potentially beneficial for applications in organic electronics, are accompanied by unfavorable trends such as increased light sensitivity, increased reactivity towards oxygen, and a higher tendency to form dimers. Therefore, the existence of the larger heptacene was controversial for several decades. We report the on-surface synthesis of heptacene from a diketone precursor on Ag(111) and show that heptacene is stabilized by the presence of the surface. The surface-assisted reaction was monitored by XPS and STM. NEXAFS and DFT provide additional insights into the orientation and the surface interaction of the molecules.