π‑Extended carbazoles exhibit intrigu­ing electronic and optical proper­ties that make them attrac­tive for diverse appli­ca­tions such as OLEDs, OFETs, and solar cells. In this project, new methods for the synthe­sis of these N‑heterocycles will be explored and their appli­ca­tion as organic materi­als will be inten­sively investigated.

In this project, the newly discov­ered Lewis acid-catalyzed reaction of naphthyl sulfil­im­ines to diben­zo­car­bazoles will be further inves­ti­gated. The goal is to eluci­date the reaction mecha­nism in detail by using various analyt­i­cal methods and theoret­i­cal studies. In addition, the newly discov­ered reaction will be extended to larger acenes such as anthracene or phenanthrene.

Using phenan­threne sulfil­im­ines, aza-[7]-helicenes are formed, which exhibit inter­est­ing optical proper­ties due to their struc­ture. The use of anthracene and naphthyl sulfil­im­ines gives π‑expanded carbazoles. These compounds also show inter­est­ing electronic and optical proper­ties. Similar carbazoles have already been success­fully used as materi­als for OLEDs, OFETs, and solar cells in organic electron­ics. The synthe­sized carbazoles are being studied in detail for their suitabil­ity as organic semicon­duc­tor materials.

Another promis­ing appli­ca­tion of carbazoles is in the synthe­sis of porphyrins with a π‑extended carbazole backbone. These partic­u­lar porphyrins are charac­ter­ized by their large conju­gated π‑system and exhibit intense absorp­tion in the near-infrared region. This property opens up poten­tial appli­ca­tions in solar cells as well as in medicine, especially in photo­dy­namic therapy.