Hydrogen Bond Boosts Circularly Polarized Radioluminescence in Chiral Mn(II) Hybrids
Jiayu Yao, Qing-Rong Ding, Hao Zeng, Jin-Yun Wang, Cui‐Mi Shi, Liang-Jin Xu, Zhong‐Ning Chen
Abstract
Abstract 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, (1 R / S ,2 R / S )‐( N , N , N ′, N ′‐tetramethyl‐1,2‐cyclohexanediamine) 2 MnBr 4 ·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 (1 R / S ,2 R / S )‐( N , N ′‐dimethyl‐1,2‐cyclohexanediamine)MnBr 4 ( 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.