Circularly Polarized Luminescence and Aggregation Induced Emission of Eu-Based Complexes With High Photoluminescence Quantum Yield

The construction of chiral rare-earth-based circularly polarized luminescence (CPL) materials with high photoluminescence quantum yields (PLQY) remains a significant challenge. Herein, we report the rational design and synthesis of two kinds of chiral Eu-based complexes exhibiting exceptional PLQY values. The enantiomeric pairs (R,R)- and (S,S)-(pybox)Eu(p-TPA)₃ demonstrated luminescence dissymmetry factors (g_lum) values of −0.0329 and +0.0241 at 588 nm with solid-state PLQY values of 89% and 91%, respectively. Meanwhile, (R)- and (S)-BPEu(p-TPA)₃ exhibited g_lum values of 0.0169 and −0.0146 at 585 nm, achieving PLQY values of 91% and 93% in the solid state. The high PLQY arises from the synergistic effects of the chiral ligands, which restrict solvent coordination and enhance structural rigidity, thereby suppressing nonradiative decay pathways. This study presents a case where chiral rare-earth-based CPL materials achieve a PLQY of over 90%.