4-Fluoro-2-methylbenzonitrile (CAS number 147754-12-9), also referred to as 2-cyano-5-fluorotoluene, is a benzonitrile derivative with a fluorine and a methyl substituents at the 4- and 2-positions. An emitter, named as 4,4'-(9H,9'H-[3,3'-bicarbazole]-9,9'-diyl)bis(2-methylbenzonitrile), with thermally activated delayed fluorescence (TADF) characteristics is synthesized using 4-fluoro-2-methylbenzonitrile and bicarbazole through nucleophilic aromatic substitution. The presence of the methyl group enhances the thermal stability of the emitter, with an initial decomposition temperature at 447 °C. The OLED device fabricated with this TADF emitter shows exceptional current efficiency (34.5 cdA-1), power efficiency (29.9 lmW-1) and external quantum efficiency (10.8%).
4-Fluoro-2-methylbenzonitrile is also an essential building block for APIs, for instance, trelagliptin succinate used for the treatment of type II diabetes.