Synthesis of Diindolocarbazoles by Ullmann Reaction: A Rapid Route to Ladder Oligo(p-aniline)s
摘要:
New and facile synthesis of symmetric diindolocarbazoles was developed using the copper-catalyzed Ullmann reaction. The key step is a double-intramolecular cyclization reaction realized on N-alkyl-3,6-dibromo-2,7-bis(2'aminophenyl)carbazole derivatives which offers the desired symmetric ladder oligo(p-aniline)s. Depending upon the nature of the side- and/or end-groups, well-defined thin films and/or semiladder polymers could be obtained. These electroactive ladder oligomers may have great potential in organic electronics.
Disclosed is an organic electroluminescent device (organic EL device) that is improved in luminous efficiency, sufficiently secures driving stability, and has a simple configuration. This organic EL device has a light-emitting layer between an anode and a cathode piled one upon another on a substrate and the said light-emitting layer contains a fused polycyclic compound in which seven or more rings are fused together as a host material. The aforementioned fused polycyclic compound has a structure formed by fusing two or more indole rings to a carbazole ring. A specific example thereof is the compound represented by the following formula.