Circularly polarized luminescence based on columnar self-assembly of tetraphenylethylene with multiple cholesterol units

The influence of different states of AIE derivative with columnar liquid crystalline phase on circularly polarized luminescence (CPL) was investigated in this work. Two novel tetraphenylethylene derivatives with multiple cholesterol units (TPE-C and TPE-SC) were prepared. They exhibited enantiotropic liquid crystalline behaviours with the ordered hexagonal columnar mesophase. They possessed excellent ME properties in H2O-THF system. The fluorescence quantum yields of TPE-C and TPE-SC at solid state were as high as 28.8% and 22.6%, respectively. The chiral transfer from cholesterol units to TPE cores was confirmed by CD spectra. The studies on CPL spectra suggested that their CPL behaviors were tuned by the different states. They showed weak CPL properties at solid and isotropic state but strong CPL luminescence at liquid crystalline phase based on the orderly columnar self-assembly. The of TPE-SC at liquid crystalline phase reached 8.83 x 10(-2).