| AVS 56th International Symposium & Exhibition | |
| Surface Science | Thursday Sessions |
| Session SS2-ThA |
| Session: | Supramolecular Interfaces by Design |
| Presenter: | M. Stöhr, University of Basel, Switzerland |
| Authors: | M. Matena, University of Basel, Switzerland J. Lobo-Checa, University of Basel, Switzerland M. Wahl, University of Basel, Switzerland H. Dil, University of Zürich, Switzerland L.H. Gade, University of Heidelberg, Germany T.A. Jung, Paul Scherrer Institute, Switzerland J. Zegenhagen, ESRF, France M. Stöhr, University of Basel, Switzerland |
| Correspondent: | Click to Email |
We reported the formation of a molecular honeycomb network generated by thermal dehydrogenation of a perylene derivative (DPDI) on a Cu(111) surface [1]. By thermal activation, these molecules become H-bond donors/acceptors and form a highly regular honeycomb structure which is commensurate to the Cu substrate. This network can be used as a template for the incorporation of guest molecules in its hexagonal “holes” [2], [3]. Besides utilizing this network for the study of guest molecules, XSW (x-ray standing wave) experiments were carried out to gain more structural information and by this more information on the molecule substrate interaction. This is done by determining the vertical height of the molecules above the Cu surface before and after annealing the sample. Before annealing, the DPDI molecule is chemisorbed. It mainly interacts via its N atoms with the Cu surface and is in a bridge-like configuration. After annealing, the height difference between the end groups and the perylene core is lowered what is required to enable H-bonding between the molecules.
Furthermore, to study the interaction between the electronic Cu surface state and the DPDI network, scanning tunneling spectroscopy (STS) and angle-resolved photoemission spectroscopy (ARPES) were used. Each pore of our porous network confines the Cu surface state in what can be described as a 0D quantum dot. Due to the imperfect confinement observed for all 0D cases studied so far on surfaces, the quantum dots couple with their neighbors resulting in shallow dispersive electronic bands [4]. A consequence of this work is the perspective to engineer these artificially created electronic structures by modification of the dimensions of the molecular network periodicities together with the appropriate choice of the substrate.
[1] M. Stöhr et al., Angew. Chem. Int. Ed. 44 (2005) 7394; [2] M. Wahl et al., Chem. Commun. (2007) 1349; [3] M. Stöhr et al., Small 3 (2007) 1336; [4] J. Lobo-Checa et al., submitted.