Sandwich-Like Supramolecular Clamp-Templated Manganese(II) Bromide Scintillators for Multimodal Visualization

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 [MnBr₄]^2- geometry, cation-associated charge collection, and glass formation. Four Mn(II) bromides, [(B15C5)₂@K]₂MnBr₄ (CKMB), [(B15C5)₂@Rb]₂MnBr₄ (CRMB), [(B15C5)₂@Sr]MnBr₄ (CSMB), and [(B15C5)₂@Ba]MnBr₄ (CBMB), were obtained. The well-matched K⁺-B15C5 clamp stabilizes a nearly ideal [MnBr₄]^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 × 10⁴ 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 × 10⁴ 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.