Sandwich‐Like Supramolecular Clamp‐Templated Manganese(II) Bromide Scintillators for Multimodal Visualization
Yuan‐Ji Ye, Hui‐E Lin, Yue‐Chen Chen, Tong Xiao, Shu‐Quan Zhang, Ming‐Hua You, Hong‐Ming Chen, Zai‐Lai Xie, Mei‐Jin LinABSTRACT
Crown ether‐regulated metal halides feature programmable host‐guest coordination and structurally defined emissive centers, making them promising for multifunctional scintillation applications. However, their strong coordination and supramolecular interactions favor ordered assembly and crystallization, hindering melt‐processing into large‐area, transparent glassy scintillator screens. Here, we develop a “three birds with one stone” strategy using sandwich‐like benzo‐15‐crown‐5‐metal supramolecular clamps to simultaneously regulate [MnBr 4 ] 2− geometry, cation‐associated charge collection, and glass formation. Four Mn(II) bromides, [(B15C5) 2 @K] 2 MnBr 4 (CKMB), [(B15C5) 2 @Rb] 2 MnBr 4 (CRMB), [(B15C5) 2 @Sr]MnBr 4 (CSMB), and [(B15C5) 2 @Ba]MnBr 4 (CBMB), were obtained. The well‐matched K + ‐B15C5 clamp stabilizes a nearly ideal [MnBr 4 ] 2− tetrahedron in CKMB, affording a photoluminescence quantum yield of 82.2%. The cationic framework contributes to the conduction‐band‐edge states and promotes X‐ray charge collection, yielding a relative light yield of 6.74 × 10 4 photons MeV −1 and a detection limit of 28.5 nGy s −1 . Meanwhile, monovalent clamp cations induce steric mismatch and packing frustration, enabling vitrification of CKMB and CRMB. CKMB‐G exhibits T g = 61°C, T g /T m = 0.87, and a retained light yield of 3.20 × 10 4 photons MeV −1 . The complementary crystalline and glassy states enable WLED emission, X‐ray imaging at 32 lp mm −1 , dynamic imaging at 2K resolution and 60 fps, and multimodal anti‐counterfeiting, highlighting supramolecular clamps as active cationic templates for multifunctional Mn(II) scintillators.