Sandwich‐Like Supramolecular Clamp Regulated Copper(I) Iodide Cluster Scintillators for Dynamic X‐ray Imaging and Multimodal Visualization

ABSTRACT Achieving the simultaneous integration of high X‐ray attenuation, emissive stability, and structural uniformity in metal‐halide scintillators remains a fundamental challenge. Herein, we present a sandwich‐like supramolecular clamp that combines rigid benzo‐15‐crown‐5 (B15C5) frameworks with alkali‐metal centers (Li, Na, Cs) to construct a family of zero‐dimensional copper(I) iodide scintillators (B15C5 2 @LiH 2 O) 2 Cu 4 I 6 (B15CLCI), (B15C5 2 @NaH 2 O) 2 Cu 4 I 6 (B15CNCI), and (B15C5 2 @Cs) 2 Cu 4 I 6 (B15CCCI). They can be scalably synthesized via mechanochemical synthesis, while B15CCCI further affords inch‐scale single crystals through solution evaporation, ensuring structural integrity and practical applicability. Besides, the B15C5 benzo‐crown ether and Cs + ion together form a sandwich‐like supramolecular clamp, where crown‐metal coordination defines the primary structural framework, a dense C─H···I hydrogen‐bonding network further rigidifies the lattice and suppresses nonradiative decay, and the heavy Cs + center enhances X‐ray attenuation. This cooperative effect minimizes structural distortion of the [Cu 4 I 6 ] 2− emissive clusters in B15CCCI, leading to a near‐unity photoluminescence quantum yield (95.6%), an ultrahigh relative light yield of 98 600 photons MeV −1, and a high spatial resolution of 31.3 lp mm −1 . Moreover, the system enables dynamic X‐ray imaging and multimodal visualization via WLED‐scintillation image fusion. This work establishes a sandwich‐like supramolecular clamp paradigm that offers a scalable and rational design strategy for high‐performance copper(I) halide scintillators.