Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 12: Organic Molecules at Surfaces 2: Characterization of Organic Monolayers
O 12.10: Talk
Monday, September 5, 2022, 17:15–17:30, S051
Steering Self-Assembly of Three-Dimensional Iptycenes on Au(111) by Tuning Molecule-Surface Interactions — Lukas Grossmann1,2, •Eva Ringel1,2, Wolfgang Heckl1,2, and Markus Lackinger1,2 — 1Deutsches Museum, Museumsinsel 1, 80538 München — 2Technische Universität München, Physics Department, James-Franck-Strasse 1, 85748 Garching
Three-dimensional organic molecules have been neglected in studies on surfaces, even though their self-assemblies exhibit a far greater variability than their planar counterparts. While planar molecules adsorb mostly flat on surfaces, three-dimensional molecules can adopt vastly different adsorption geometries. This additional degree of freedom can result in self-assembly of entirely different supramolecular structures. Moreover, adsorption geometries can be steered by tuning molecule-surface interactions, thereby providing a new means for 2D crystal engineering. In this respect, iptycenes are highly stable, but currently underexplored model compounds. Here, we study self-assembly of three-fold symmetric triptycene derivates with extended anthracene blades on Au(111) surfaces. Additionally, the influence of intrinsic dipole moments was investigated by comparing analogs with peripheral fluorine substitution. All structures were resolved by Scanning-Tunneling-Microscopy under ultra-high vacuum conditions. On pristine Au(111), the molecules maximize the area of contact, whereas iodine-passivation affords hexagonal porous structures that feature optimized molecule-molecule interactions through face-to-face stacking of all anthracene blades.