title: Substituted Tetraaza- and Hexaazahexacenes and their N,N'-Dihydro Derivatives: Syntheses, Properties, and Structures.
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.
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg (Germany).
authors.forename: Jens U
authors.initials: JU
authors.lastname: Engelhart
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg (Germany).
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Lindner
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg (Germany).
authors.forename: Manuel
authors.initials: M
authors.lastname: Schaffroth
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg (Germany).
authors.forename: David
authors.initials: D
authors.lastname: Schrempp
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg (Germany).
authors.forename: Olena
authors.initials: O
authors.lastname: Tverskoy
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg (Germany). uwe.bunz@oci.uni-heidelberg.de.|Centre for Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120 Heidelberg (Germany). uwe.bunz@oci.uni-heidelberg.de.
authors.forename: Uwe H F
authors.initials: UH
authors.lastname: Bunz
keywords: amination; cross-coupling; heteroacenes; oxidation; palladium