Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• DOI: 10.3762/bjoc.19.139
• Publication Date: 2023-12-12T09:55:47Z
• Authors: Karolis Leitonas; Brigita Vigante; Dmytro Volyniuk; Audrius Bucinskas; Pavels Dimitrijevs; Sindija Lapcinska; Pavel Arsenyan; Juozas Vidas Graz...
• Keywords: Sonogashira coupling; Moiety

The pyridine-3,5-dicarbonitrile moiety has gained significant attention in the field of materials chemistry, particularly development heavy-metal-free pure organic light-emitting diodes (OLEDs). Extensive research on compounds exhibiting thermally activated delayed fluorescence (TADF) led to numerous patents and articles. This study focuses synthesis investigation semiconducting properties polyaromatic π-systems containing two three fragments pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile. are synthesized by Sonogashira coupling reactions characterized steady-state time-resolved luminescence spectroscopy. show efficient intramolecular charge transfer (ICT) from donor acceptor. photoluminescence (PL) spectra solutions showed non-structured emission peaks visible region, which attributed ICT emission. PL intensities enhanced after deoxygenation, is indicative TADF. quantum yields TADF sensitive medium. Cyclic voltammetry measurements indicate good hole-blocking electron-injecting due their high ionization potentials. Photoelectron spectroscopy time-of-flight reveal electron-transporting for one compounds. In general, with demonstrate promising potential use electronic devices, such as OLEDs.