Dresden 2017 – wissenschaftliches Programm
CPP 48.12: Poster
Mittwoch, 22. März 2017, 18:30–21:00, P2-OG1
Self-assembly of Partially Fluorinated Hexabenzocoronene Derivatives in the Solid State — •Tobias Breuer1, Michael Klues1, Pauline Liesfeld2, Andreas Viertel2, Matthias Conrad1, Stefan Hecht2, and Gregor Witte1 — 1Philipps-Universität Marburg, Germany — 2Humboldt-Universität Berlin, Deutschland
Fluorination of polycyclic aromatic hydrocarbons (PAHs) is a wellestablished method to enhance the stability of organic semiconductors (OSCs) and render them n-type. For hexabenzocoronene (HBC) it has been observed that fluorination leads to a modification of the molecular
packing motif from a herringbone arrangement to a parallel-packed motif. Here, we study whether this transformation of the molecular packing is also found for newly synthesized, partially fluorinated HBCs.
Combining powder diffraction and NEXAFS dichroism measurements, we reveal that indeed all partially fluorinated compounds adopt a parallel molecular packing, hence maximizing the intermolecular contact area. We identify fluorine-hydrogen bonds as mediating driving force to stabilize this molecular arrangement. Furthermore, we show that the relative orientation of the HBCs on the underlying surface can be precisely
controlled by varying substrate materials. Finally, the energetic states of the compounds are analyzed by photoelectron spectroscopy, optical spectroscopy and DFT to identify the effects of fluorination on these fundamental electronic characteristics.
T. Breuer et al., PCCP, 2016, DOI: 10.1039/C6CP06126E