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 Cu28(S-c-C6H11)18(PPh2Py)3H82+ (Cu28-PPh2Py for short) with only one C 1 symmetry axis was synthesized using a one-pot method under mild conditions, and its structure was determined. Through ligand regulation, a 29th copper atom was inserted into the surface vacancy site to give two non-defective copper hydride nanoclusters, namely Cu29(SAdm)15Cl3(P(Ph-Cl)3)4H10+ (Cu29-P(Ph-Cl)3 for short) with one C 3 symmetry axis and (Cu29(S-c-C6H11)18(P(Ph-pMe)3)4H10)+ (Cu29-P(Ph-Me)3 for short) with four C 3 symmetry axes. The optimized structures show that the 10 hydrides cap four triangular and all six square-planar structures of the cuboctahedral Cu13 core of Cu29-P(Ph-Me)3, while the 10 hydrides cap four triangular and six square-planar structures of the anti-cuboctahedral Cu13 core of Cu29-P(Ph-Cl)3, with the eight hydrides in Cu28-PPh2Py capping four triangular and four square planar-structures of its anti-cuboctahedral Cu13 core. Cluster stability was found to increase sequentially from Cu28-PPh2Py to Cu29-P(Ph-Cl)3 and then to Cu29-P(Ph-Me)3, 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 Cu28-PPh2Py to Cu29-P(Ph-Cl)3 and then to Cu29-P(Ph-Me)3, 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.