Synthesis and characterization of triphenylethylene derivatives with aggregation-induced emission characteristics

New aggregation-induced emission (AIE) compounds derived from triphenylethylene were synthesized. The thermal, photophysical, electrochemical and aggregation-induced emissive properties were investigated. All the compounds had strong blue light emission capability and good thermal stability. Their maximum fluorescence emission wavelengths were between 443 to 461 nm in solid states, while their glass transition temperatures ranged from 86 to 129 °C. The decomposition temperatures of the synthesized compounds were in the range of 432-534 °C. The synthesized compounds possessed aggregation-induced emission properties, namely exhibited enhanced fluorescence emission in aggregated states. The highest occupied molecular orbital (HOMO) energy levels estimated from the oxidation potentials were between 5.61 and 5.66 eV and the lowest unoccupied molecular orbital/highest occupied molecular orbital (LUMO/HOMO) energy gap values were found to be in the range of 3.18-3.22 eV. The compounds 4-(4-(2,2-bis(4-(naphthalen-1-yl)phenyl)vinyl)phenyl) dibenzothiophene [(BN)(2)Bt] and 4-(4-(2,2-di(biphenyl-4-yl)vinyl)phenyl) dibenzothiophene [(BB)(2)Bt] exhibited vibronic fine-structure photoluminescence spectra when the water fraction was less than 70%.