Heterocycle-based luminogens with aggregation-induced emission characteristics

Aggregation-induced emission (AIE) is a new concept—the term was coined by Ben Zhong Tang of the Hong Kong University of Science & Technology (HKUST) in 2001, and refers to a unique photo-physical phenomenon in which some nonplanar-shaped luminogens emit faintly in their dilute solutions, but show remarkably enhanced luminescence upon aggregation. The AIE is exactly opposite to the notorious aggregation-caused quenching (ACQ) effect, which has been regarded as a general phenomenon for