Regensburg 2022 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 40: Organic Molecules at Surfaces 4: Chemistry on Surfaces
O 40.8: Vortrag
Mittwoch, 7. September 2022, 12:15–12:30, S051
Surface chemistry of dibromoindigo - effects of temperature and type of surface — •Manuela Hocke1,2, Michael Schmittel3, Wolfgang Heckl1,2, and Markus Lackinger1,2 — 1Deutsches Museum, 80538 München — 2Technische Universität München, Physics Department, 85748 Garching — 3Center of Micro and Nanochemistry, Universität Siegen, 57068 Siegen, Germany
Mother Nature offers a great variety of suitable halogenated compounds, which can readily be used as precursor for on-surface Ullmann couplings. Here, we study the thermally activated surface chemistry of the famous dye Tyrian purple (6,6'-dibromoindigo) comparatively on Ag(111) and Au(111) by Scanning-Tunneling-Microscopy. On Au(111) we observed two distinct self-assembled structures comprised of fully intact molecules. Covalent structures were obtained either by deposition onto hot surfaces or subsequent heating, where the heating rate is crucial. On Ag(111) only one self-assembled structure was observed. The organometallic structures obtained upon debromination rarely exhibited the anticipated linear structure. Instead, we find remarkably diverse structures. The additional functionalization of 6,6'-dibromindigo with potent H-bond donor and acceptor groups renders the on-surface polymerization of this compound particularly prone to additional influences of supramolecular bonds with a vivid contribution of the co-adsorbed dissociated bromine atoms. Moreover, the surprisingly large variation of the organometallic structures on Ag(111) and the profound dependence on preparation parameters indicate an unexpectedly large kinetic influence.