Multilevel Structural Design of Chiral Lanthanide Complexes Enhancing Circularly Polarized Luminescence for Information Encryption

The concurrent enhancement of the dissymmetry factor ( g lum ) and photoluminescence quantum yield (Φ lum ) remains a long-standing challenge in chiral circularly polarized luminescence (CPL) materials. Here, we propose a multilevel structural design strategy that integrates pH-regulated in situ ligand hydrolysis, mixed-ligand coordination, supramolecular self-assembly, and polymer matrix embedding to address this issue. Through the controlled hydrolysis of chiral oxazoline-based ligands, enantiomeric lanthanide complexes ( R -/ S -Lna and R -/ S -Lnb, Ln = Eu/Tb) were obtained. The mixed-ligand system R -/ S -Lnb exhibits larger g lum values (0.027/–0.028 for R -/ S -Eub, 0.010/–0.012 for R -/ S -Tbb ) and higher Φ lum values ((75.2 ± 0.2)% for R -Eub and (81.5 ± 0.5)% for R -Tbb ). By embedding R -/ S -Lnb into PMMA matrices, we fabricate optically transparent, stable, and processable CPL-active thin films R -/ S -Lnb@PMMA . The Φ lum value of R -Tbb@PMMA is as high as (91.6 ± 0.6)%. Taking advantage of the dual photoluminescence and CPL features of R -/ S -Lnb@PMMA films, we demonstrate their proof-of-concept applications in optical information storage and encryption.