Structured copper-hydride nanoclusters provide insight into the surface-vacancy-defect to non-defect structural evolution.

Exploring the structural evolution of clusters with similar sizes and atom numbers induced by the removal or addition of a few atoms contributes to a deep understanding of structure-property relationships. Herein, three well-characterized copper-hydride nanoclusters that provide insight into the surface-vacancy-defect to non-defect structural evolution were reported. A surface-defective copper hydride nanocluster [Cu(S--CH)(PPhPy)H] (Cu-PPhPy for short) with only one symmetry axis was synthesized using a one-pot method under mild conditions, and its structure was determined. Through ligand regulation, a 29 copper atom was inserted into the surface vacancy site to give two non-defective copper hydride nanoclusters, namely [Cu(SAdm)Cl(P(Ph-Cl))H] (Cu-P(Ph-Cl) for short) with one symmetry axis and (Cu(S--CH)(P(Ph-Me))H) (Cu-P(Ph-Me) for short) with four symmetry axes. The optimized structures show that the 10 hydrides cap four triangular and all six square-planar structures of the cuboctahedral Cu core of Cu-P(Ph-Me), while the 10 hydrides cap four triangular and six square-planar structures of the anti-cuboctahedral Cu core of Cu-P(Ph-Cl), with the eight hydrides in Cu-PPhPy capping four triangular and four square planar-structures of its anti-cuboctahedral Cu core. Cluster stability was found to increase sequentially from Cu-PPhPy to Cu-P(Ph-Cl) and then to Cu-P(Ph-Me), which indicates that stability is affected by the overall structure of the cluster. Structural adjustments to the metal core, shell, and core-shell bonding model, in moving from Cu-PPhPy to Cu-P(Ph-Cl) and then to Cu-P(Ph-Me), enable the structural evolution and mechanism responsible for their physicochemical properties to be understood and provide valuable insight into the structures of surface vacancies in copper nanoclusters and structure-property relationships.