Aggregation-Induced Emission of Tetraarylethene Luminogens

It has been a textbook knowledge that chromophore aggregation generally quenches light emission. While in 2001, we discovered a novel phenomenon of aggregation-induced emission (AIE): a series of propeller-shaped molecules were found nonluminescent in the solution state but emissive in the aggregate and solid states. Attracted by the intriguing phenomenon and its fascinating perspectives, we launched a research program on developing new AIE luminogens and exploring their high-tech applications. In this review, we present our recent works on developing a novel AIE system based on tetraarylethenes. We show that restriction of intramolecular rotation is the main cause for the AIE effect. Utilizing such treasured AIE characteristics, the tetraarylethenes can find an array of applications, including fluorescence sensors, biological probes, and active materials in the fabrication of organic light-emitting diodes. Keywords: Chromophore, aggregation, tetraarylethene, light emission, light-emitting diode, excimer, sensor, biological probe