Hydrogen Bond Boosts Circularly Polarized Radioluminescence in Chiral Mn(II) Hybrids

Chiral scintillators combining scintillation and circularly polarized luminescence (CPL) present a novel avenue for controlling light propagation and reducing optical crosstalk in conventional scintillators. However, quantitative evaluation of circularly polarized radioluminescence (CPRL) and strategies for enhancing performance under X-ray excitation remain underexplored. Herein, we conducted the designed synthesis of Mn(II) hybrid enantiomers, (1R/S,2R/S)-(N,N,N',N'-tetramethyl-1,2-cyclohexanediamine)₂MnBr₄·2Br^- (R/S-1), which exhibit intense CPL with photoluminescence (PL) quantum yields of 94.4% (R-1) and 94.1% (S-1) and PL dissymmetry factors (g_PL) of -3.87 × 10^-3 (R-1) and + 3.98 × 10^-3 (S-1). They demonstrate strong scintillation performance with record-breaking light yields of 70 061 and 68 514 photons/MeV in chiral scintillators. We pioneered quantitative evaluation of the CPRL of R/S-1, achieving radioluminescence (RL) dissymmetry factors (g_RL) of -2.04 × 10^-3 and + 2.55 × 10^-3. By incorporating hydrogen bonds into the structures through rational ligand design to facilitate chiral transfer, Mn(II) hybrid enantiomers (1R/S,2R/S)-(N,N'-dimethyl-1,2-cyclohexanediamine)MnBr₄ (R/S-2) achieve the g_PL values of -2.56 × 10^-2 and + 2.50 × 10^-2 with nearly seven times higher than those of R/S-1. More inspiringly, the g_RL value of R-2 increased to -2.96 × 10^-2 with a 15 times increase relative to R-1, representing the highest CPRL in lead-free chiral scintillators. This work not only manifests a new design strategy for advancing chiral scintillators but also establishes a standard approach for evaluating CPRL properties.