Efficient Syntheses of Novel Fluoro‐Substituted Pentacenes and Azapentacenes: Molecular and Solid‐State Properties |
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| Authors: | Jonas Schwaben Niels Münster Michael Klues Dr Tobias Breuer Philipp Hofmann Dr Klaus Harms Prof?Dr Gregor Witte Prof?Dr Ulrich Koert |
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| Affiliation: | 1. Fachbereich Chemie, Philipps‐Universit?t Marburg, Hans‐Meerwein‐Stra?e 4, 35043 Marburg (Germany), Fax: (+49)?6421‐2825677 http://www.uni‐marburg.de/fb15/ag‐koert;2. Fachbereich Physik, Philipps‐Universit?t Marburg, Renthof 7, 35032 Marburg (Germany), Fax: (+49)?6421‐2821384 http://www.uni‐marburg.de/fb13/molfk |
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| Abstract: | Non‐symmetrical 6,13‐disubstituted pentacenes bearing trifluoromethyl and aryl substituents have been synthesized starting from pentacenequinone. Diazapentacenes with a variety of fluorine substituents were prepared either via a Hartwig–Buchwald aryl amination route or by a SNAr strategy. As a result of a non‐symmetric substitution pattern containing electron‐donating substituents in combination with electron‐accepting fluorine substituents, the synthesized compounds feature distinct molecular dipoles. All compounds are analyzed regarding their optoelectronic properties in solution with special focus on the frontier orbital energies as well as their molecular packing in the crystal structures. The analyses of isolated molecules are complemented by thin‐film studies to examine their solid‐state properties. A precise comparison between these and the molecular properties gave detailed insights into the exciton binding energies of these compounds, which are explained by means of a simple model considering the molecular packing and polarizabilities. |
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| Keywords: | acene fluorinated compounds optical properties organic solids synthesis |
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