Synthesis of carbazole derivatives with high quantum yield and high glass transition temperature

A series of fluorescent compounds derived from carbazole were synthesized via the Wittig–Horner reaction. The compounds had high glass transition temperatures (T_g), in the region of 172–232 °C, and high decomposition temperatures (T_d), ranging from 456 to 491 °C. The derivatives showed very high fluorescence efficiency in solution, with fluorescence quantum yields in the range of 0.88–1.00. The substituent effects on fluorescence emission differed between solution and solid state. In dichloromethane solutions, the substituents had only a minimal effect on the maximum emission wavelength of the compounds with the same bridge.