Tetraphenylethylene-rufigallol-tetraphenylethylene trimers: Novel fluorescence liquid crystals in aggregated states

This work reported two novel liquid crystals with good fluorescence in aggregated states. Two tetraphenylethylene-rufigallol-tetraphenylethylene trimers (compounds 6a and 6b ) were prepared in simple procedure. The columnar liquid crystalline behaviors of 6a and 6b were confirmed by the analysis of differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction. Compound 6b exhibited an ordered hexagonal columnar mesophase. They possessed excellent AIE fluorescence properties in THF-H 2 O solution, solid film and mesophase. The fluorescence quantum yields of compounds 6a and 6b were 12% and 22% in solid films, 14% and 24% in mesophase, respectively. The experimental results showed that the liquid crystalline properties and fluorescence properties were tuned by the lengths of the terminal alkyl chains.