Bromination Improves the Electron Mobility of Tetraazapentacene

• Published in: Angewandte Chemie International Edition Vol. 57; no. 30; pp. 9543 - 9547
• Main Authors: Reiss, Hilmar, Ji, Lei, Han, Jie, Koser, Silke, Tverskoy, Olena, Freudenberg, Jan, Hinkel, Felix, Moos, Michael, Friedrich, Alexandra, Krummenacher, Ivo, Lambert, Christoph, Braunschweig, Holger, Dreuw, Andreas, Marder, Todd B., Bunz, Uwe H. F.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 20.07.2018; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: azaacenes; Bromination; Chemistry; Chemistry, Multidisciplinary; Electron mobility; n-channel semiconductors; Physical Sciences; radical anions; Science & Technology; Semiconductor devices; thin-film transistors; Tips; Transistors; azaacenes; radical anions; PERFORMANCE; N-HETEROACENES; EMITTERS; FIELD-EFFECT TRANSISTORS; LIGHT-EMITTING-DIODES; FUNCTIONALIZED ACENES; thin-film transistors; ORGANIC ELECTRONICS; PENTACENE; n-channel semiconductors; bromination
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201805728

A cyclocondensation of TIPS‐ethynyl‐substituted diaminoarenes with in situ obtained 4,5‐dibromocyclohexa‐3,5‐diene‐1,2‐dione has led to the synthesis of tetrabromotetraazapentacene (BrTAP). BrTAP is easily reduced to its air‐stable radical anion and electron mobilities >0.56 cm2 V−1 s−1 can be achieved in thin‐film transistors. A fully air‐stable radical anion is formed from a bis‐TIPS‐ethynyl‐substituted tetraazapentacene with four bromine substituents attached in the 2‐, 3‐, 9‐, and 10‐positions. The deep‐lying LUMO (i.e. high electron affinity) makes this material a promising n‐channel semiconductor, as the bromine substituents stabilize charge and lead to a charge distribution that favors the outer rings, which allows better charge transport in the crystalline state.