Gram-Scale Preparation of Stable Hydride M@Cu₂₄ (M = Au/Cu) Nanoclusters

The instability of phosphine ligated copper hydride nanoclusters (CuH NCs) has largely limited their application in areas such as H₂ storage, CO₂ reduction, etc. In this work, the stability of CuH NCs was remarkably enhanced by improving their antioxidant capacity through two different approaches: (i) metal doping and (ii) ligand modification. Three NCs, AuCu₂₄H₂₂(PPh₃)₁₂, Cu₂₅H₂₂((p-FPh)₃P)₁₂, and AuCu₂₄H₂₂((p-FPh)₃P)₁₂, were controllably synthesized, and their structures were determined by single-crystal X-ray diffraction. The compositions of these NCs were further confirmed by electrospray ionization mass spectrometry and nuclear magnetic resonance. More importantly, we achieved gram-level production of M@Cu₂₄ (M = Cu/Au) NCs protected by electron-withdrawing ligands (p-FPh)₃P, which in turn proved their superior stability; such a large-scale preparation laid the foundation for future explorations of copper-rich NCs. This work hopes to shed light on large-scale generation of ultrastable Cu-based NCs.