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 [(C₂)₈@Cu₅₀] (Cu₅₀) and [(C₂)₁₀@Cu₅₆] (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 CF₃COO⁻ 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.