Chiral Gadolinium Halides with Narrow Ultraviolet B Circularly Polarized Luminescence

Circularly polarized luminescence (CPL) in the ultraviolet B (UVB) region holds great potential applications in asymmetric catalysis, enantioselective polymerization, and polarization-based optical anticounterfeiting and information encryption. However, to date, the CPL materials in the UVB region remain unexplored. In this study, the first chiral gadolinium-based organic-inorganic hybrid metal halides, (R/S-C₃H₇NF₃)₃GdCl₆ (R/S-3F-Gd), were constructed, which exhibit efficient CPL in the UVB region. Owing to the unique 4f-4f transition of Gd³⁺ ions, R/S-3F-Gd shows a high photoluminescent quantum yield of 18%, a narrow full width at half maximum (∼3 nm) and a ultralong photoluminescence lifetime (∼6.6 ms). Additionally, their CPL can be further tuned by applying the external magnetic field. Then the light-emitting diode (LED) chips coated with R- or S-3F-Gd were also fabricated, which exhibit high dissymmetry factor of + 9.1 × 10^-3 and -8.2 × 10^-3, further demonstrate their potential as circularly polarized light source in the UVB region. Our work offers a novel strategy for designing the chiral luminescent materials with efficient CPL response in the UVB region and broadens the family of chiral organic-inorganic hybrid rare-earth halides.