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Updated: May 14, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Large N-heteroacenes: new tricks for very old dogs?
Uwe H F Bunz1, Jens U Engelhart, Benjamin D Lindner
1Organisch-Chemisches Institut, Ruprecht-Karls-Universität, Im Neuenheimer Feld 270, 69120 Heidelberg, Gemany. uwe.bunz@oci.uni-heidelberg.de
Abstract:
Azaacenes have been known for a very long time, either as N,N'-dihydro compounds or in their oxidized form as 4n+2π systems, but only recently have processable and charcterizable derivatives been sought. In the last three years synthetic routes to large N-heteroacenes have been developed. In particular, the Pd-catalyzed coupling of aromatic diamines with activated aromatic dihalogenides has enabled simple access to numerous new azaacenes. Since 2010, azapentacene and stabile oligoazahexacene have been synthesized, as well as a symmetrical tetraazapentacene, which acts as an excellent electron-transport material for thin-film transistors.
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