Synthesis and properties of aggregation-induced emission enhancement compounds derived from triarylcyclopentadiene

A series of triarylcyclopentadiene derivatives were synthesized and their crystal structures and photoluminescence properties in solution and aggregation state were studied. Their maximum fluorescence emission wavelengths were 452-483 nm. Four of them have weak emission in solution but intense emission when aggregated in water/acetonitrile mixture or in crystals showing a typical aggregation-induced emission enhancement (AIEE). The crystal structure analysis reveals that the aromatic C-H center dot center dot center dot pi interactions are the origin of the AIEE. Additionally, DFT calculations, and the thermal and electrochemical properties of these compounds were investigated.