Recent advances and importance of triphenyl acrylonitrile system as an aggregation-induced emitter

Abstract

Aggregation-induced emitters (AIEgens) have emerged as versatile materials capable of meeting the demands of diverse applications, including optoelectronic devices, bioimaging, chemical sensing, and addressing environmental and industrial challenges. Among the various molecules exhibiting aggregation-induced emission (AIE), tetraphenylethylene (TPE) has been extensively studied due to its robust AIE activity. Current research focuses on modifying TPE structures to fine-tune their optoelectronic properties for specific applications. Triphenyl acrylonitrile (TPAN), a derivative of TPE where one phenyl group is replaced with a cyano group, has garnered significant attention. The strong electron-withdrawing nature cyano group enhances electronic properties of the materials. Dipolar compounds based on TPAN exhibit notable intramolecular charge transfer, in addition to well-established AIE properties and mechanofluorochromism. This review highlights recent advancements in the design of AIEgens incorporating TPAN, including systems based on carbazole, pyrene, triphenylamine, and other heterocycles. Where available, comparisons are made between AIEgens derived from TPE and TPAN, providing insights into the advantages and unique characteristics of each system.