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.