Cyclic Polyenes with Aggregation-Induced Emission Characteristics

Chromophoric cyclic polyenes including 4H-pyrans,fulvenes,and siloles are designed and synthesized.Unlike(conventional) luminescent molecules,these polyenes are practically nonemissive when molecularly (dissolved,) but become highly luminescent with a dramatic increase in efficiency when aggregated(hence aggregation-induced emission or AIE).Upon exposure to solvent vapors,their emissions on TLC plates are quenched but become visible again when the vapors are removed.This process is reversible and can be repeated many times.Their emissions can also be tuned by changing their packing patterns such as from crystalline to amorphous state or from one crystal form to another crystal form.