Atomically precise Cu32 nanoclusters with selenide doping: Synthesis, bonding, and catalysis

Copper nanoclusters with stable compositions and precise structures have long been sought after, as they possess properties that are absent in gold and silver counterparts. However, the creation of copper nanoclusters with novel compositions, structures, and functionalities remains largely unexplored in the literature. In this study, we demonstrate that selenide doping is an effective method for fabricating stable copper nanostructures through controlled synthesis and structure determination of a copper–selenide nanocluster. The nanocluster of [Cu₃₂Se₇(BnSe)₁₈(PPh₃)₆]⁺ (denoted as Cu₃₂Se₇, Bn is benzyl) has been prepared by reducing copper salts in the presence of organic diselenides. The atomic structure of the Cu₃₂Se₇ cluster, accurately determined through single-crystal X-ray diffraction, reveals a core–shell arrangement of Cu₂₀Se₇@Cu₁₂(BnSe)₁₈(PPh₃)₆, where Se²⁻ anions are well dispersed in the Cu₂₀ framework. Notably, this cluster represents a rare example of copper–selenide semiconductor nanoclusters. Experimental and theoretical analysis shows strong interactions between Se ligands and metal atoms, resulting in high stability of the Cu₃₂Se₇ cluster. Furthermore, the cluster exhibits excellent catalytic performance in the hydroboration reaction of alkynes, producing a range of vinylboron compounds with adjustable structures and functions. Importantly, the cluster undergoes no structural or nuclearity changes during the reaction, as confirmed by extended X-ray absorption fine structure and X-ray photoelectron spectroscopy studies. This study not only presents a molecular cluster model highlighting the effectiveness of selenide dopants in fabricating new copper nanostructures but also paves the way for utilizing stable copper nanoclusters in diverse and exciting areas beyond catalysis.