Substituted Tetraaza‐ and Hexaazahexacenes and their N,N′‐Dihydro Derivatives: Syntheses,Properties, and Structures |
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| Authors: | Jens U. Engelhart Dr. Benjamin D. Lindner Manuel Schaffroth David Schrempp Olena Tverskoy Prof. Uwe H. F. Bunz |
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| Affiliation: | 1. Organisch‐Chemisches Institut, Ruprecht‐Karls‐Universit?t Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg (Germany);2. Centre for Advanced Materials, Ruprecht‐Karls‐Universit?t Heidelberg, Im Neuenheimer Feld 225, 69120 Heidelberg (Germany) |
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| Abstract: | The palladium‐catalyzed coupling of a substituted o‐diaminoanthracene and a substituted o‐diaminophenazine to substituted 2,3‐dichloroquinoxalines furnishes 10 differently substituted N,N′‐dihydrotetraaza‐ or ‐hexaazahexacenes with the quinoxaline group of the azaacenes carrying fluorine, chlorine, or nitro groups. The N,N′‐dihydrotetraazahexacenes with hydrogen, chlorine, and fluorine subtituents are oxidized to azaacenes, whereas only the parent N,N′‐dihydrohexaazahexacenes, with hydrogen substituents, are oxidized by MnO2. The resultant azaacenes are characterized by their optical and spectroscopic data. In addition, single‐crystal X‐ray structures have been obtained for the parent tetraazahexacenes and their difluoro‐substituted derivatives. The di‐ and tetrachloro derivatives of the N,N′‐dihydrohexaazahexacene have also been structurally characterized. |
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| Keywords: | amination cross‐coupling heteroacenes oxidation palladium |
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