Regensburg 2022 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 39: Molecular Electronics and Excited State Properties
CPP 39.1: Vortrag
Donnerstag, 8. September 2022, 11:30–11:45, H38
Fluorinated Acenes: Controlling Molecular Electronic Levels, Crystalline Phases and Optoelectronic Properties — •Daniel Bischof1, Philipp E. Hofmann2, Matthias W. Tripp2, Marc Zeplichal3, Sebastian Anhäuser1, Tobias Breuer1, Sergei I. Ivlev2, Marina Gerhard1, Andreas Terfort3, Ulrich Koert2, and Gregor Witte1 — 1Fachbereich Physik, Philipps-Universität Marburg — 2Fachbereich Chemie, Philipps-Universität Marburg — 3Goethe Universität Frankfurt
Acenes serve as prototypical molecular materials to study structure-property relationships. Here, we systematically analyze the influence of the acene length and the degree of fluorination on their structure and optoelectronic properties [1-3]. Our results show that the optical gap decreases with increasing acene length, while the degree of fluorination determines the precise energy levels of the frontier orbitals HOMO and LUMO, whereas the optical gap is barely affected upon fluorination. Partial fluorination also influences the molecular electrostatic potential (MEP) and leads to a change in the molecular packing from herringbone packing for pristine and perfluorinated acenes to a planar stacking motif. These structural changes also affect the photoluminescence properties and induce a red-shifted PL for the stacked molecules due to excimer formation. The presented insights are not limited to acenes, but can be extended to other π-conjugated systems.
[1] P. E. Hofmann, et al. Angew. Chem. Int. Ed. 59, 16501 (2020).
[2] D. Bischof et al. J. Phys. Chem. C 125, 19000 (2021).
[3] D. Bischof et al. Chem. Eur. J. 28, e202103653 (2022).