Aggregation induced emission (AIE) characteristics and main working mechanism for AIE: Restriction of intramolecular rotation

Luminogenic materials with aggregation-induced emission (AIE) have been paid much attention since it was first discovered by Tang et al in 2001. Attracted by fascinating potential, many groups have worked on the structure-property relationships, working mechanisms, and operating principles of the AIE process to design and synthesize new AIE luminogens with efficient luminescence. Restriction of intramolecular rotation (RIR) was proposed as the main mechanism for the AIE phenomenon. In this review, we will focus on this mechanism, discuss more details about the structure-property relationship of several typical compounds to deep insight into the RIR mechanism.