Core–shell [Cu45(C6H11S)24(P(PhF)3)4H19]2+ nanocluster: synthesis, structure and catalytic hydroboration

Abstract

Precise structural regulation of metal nanoclusters is critical for optimizing their catalytic performance. In this work, a core–shell copper–hydride nanocluster [Cu₄₅(C₆H₁₁S)₂₄(P(PhF)₃)₄H₁₉]²⁺ was successfully synthesized via a one-pot method. Single-crystal X-ray diffraction (SCXRD), electrospray ionization mass spectrometry (ESI-MS), and X-ray photoelectron spectroscopy (XPS) were employed to characterize the nanocluster, confirming its structure consists of a Cu₁₁@Cu₁₅ core encapsulated by a cage-like Cu₁₉((C₆H₁₁S)₂₄(P(PhF)₃)₄) shell, with all Cu atoms in the +1-oxidation state. Density functional theory (DFT) calculations clarified the positions of hydride atoms, electronic structure, and optical absorption properties of the nanocluster. Catalytic tests demonstrated that [Cu₄₅(C₆H₁₁S)₂₄(P(PhF)₃)₄H₁₉]²⁺ exhibited excellent activity in the hydroboration of terminal alkynes, achieving a maximum product yield of 98.3% under optimized conditions. It also showed good compatibility with substrates bearing electron-withdrawing groups or electron-donating groups. This study bridges precise atomic-level design and catalytic application of copper nanoclusters, providing both experimental and theoretical insights for their future development in homogeneous catalysis.