Chiral Thermally Activated Delayed Fluorescence-Active Macrocycles Displaying Efficient Circularly Polarized Electroluminescence

An efficient strategy for constructing chiral macrocycles with both thermally activated delayed fluorescence (TADF) and highly efficient circularly polarized electroluminescence (CPEL) properties was developed. Consequently, a pair of macrocyclic enantiomers (+)-(R,R)-MC and (-)-(S,S)-MC was synthesized by a combination of chiral octahydro-binaphthol moiety with triazine-based TADF skeleton. The chiral macrocycles exhibited obvious TADF properties with a low Delta E-ST of 0.067 eV, aggregation-induced emission behaviors, and high photoluminescence quantum yields of up to 79.7%. Moreover, the macrocyclic enantiomers showed mirror images in circular dichroism spectra and circularly polarized luminescence signals. Especially, the chiralmacrocycleswere suitable for the preparation of solution-processed circularly polarized organic light-emitting diodes, which displayed excellent device performances with a highmaximum external quantum efficiency of up to 17.1%, low-efficiency roll-off of 3.5% at 1000 cdm(-2), andintenseCPELalong with electroluminescence dissymmetry factor of 1.7 x 10(-3).

Automated summary

An efficient strategy for constructing chiral macrocycles with both TADF and CPEL properties was developed. The macrocycles exhibited aggregation-induced emission and high photoluminescence quantum yields, and were suitable for the preparation of high-performance circularly polarized organic light-emitting diodes.