Ligand-passivated Au/Cu nanoclusters with uncoordinated sites give reaction turnover numbers of up to 4 × 104

Abstract

Ligand-passivated metal nanoclusters with both high stability and catalytic activity have been pursued for a long time to shed light on the underlying rationale of ligand-functionalized metal nanocatalysts in chemical transformations. Nevertheless, these atomically precise nanocatalysts often exhibit low catalytic activity due to the extensive coverage of active sites. In this work, we report a robust gold–copper alloy nanocluster with 74 nuclei with high catalytic performance. The nanocluster with molecular composition of Au₄₁Cu₃₃(RS)₄₀(MeCN) (RSH is 4-fluorothiophenol) has been obtained in a simple way. The cluster contains 34 free electrons, making it a superatom that exhibits high thermal stability as envisioned. Surprisingly, rich uncoordinated copper sites are present on the surface of the cluster, leading to its extremely high catalytic activity (up to 39 269 TON) in C–O coupling reactions with a broad substrate scope.