Hydrogen‐Bonding‐Assisted Assembly of Stable High‐Nuclearity Copper(I)‐Alkyne Nanoclusters for X‐Ray Scintillation

Abstract The construction of high‐nuclearity, atomically precise copper(I)‐alkyne nanoclusters remains a formidable challenge due to their high reactivity and strong aggregation tendency. Here, we report a hydrogen‐bonding‐assisted assembly strategy that enables the ambient‐condition synthesis of two robust copper(I)‐alkyne nanoclusters. Single‐crystal X‐ray diffraction reveals the different core structures including [(C 2 ) 8 @Cu 50 ] ( Cu50 ) and [(C 2 ) 10 @Cu 56 ] ( Cu56 ). Both clusters feature distinctive metal shells stabilized by synergistic Cu─C/O coordination interactions and an extensive outer‐layer hydrogen‐bonding network between the hydroxyl groups of 2‐methyl‐3‐butyn‐2‐ol and CF 3 COO − ligands, enhancing molecular rigidity and inoxidizability. Notably, Cu50 displays strong yellow phosphorescence and prominent X‐ray‐excited luminescence (XEL). More significantly, it represents the first high‐nuclearity copper nanocluster to be processed into a scintillator film, which exhibits promising X‐ray imaging performance. The present work not only establishes a generalizable hydrogen‐bond‐assisted assembly strategy for constructing stable, high‐nuclearity copper(I)‐alkyne nanoclusters, but also demonstrates their practical applicability in X‐ray scintillation, providing new insights into the synthetic design and functional diversification of nanocluster‐based materials.