Cu14 Cluster with Partial Cu(0) Character: Difference in Electronic Structure from Isostructural Silver Analog

An atom-precise Cu⁰-containing copper cluster, Cu₁₄(C₂B₁₀H₁₀S₂)₆(CH₃CN)₈ (abbreviated as Cu₁₄-8CH₃CN) is reported, which is synthesized via a simultaneous reduction strategy and fully characterized by single-crystal X-ray diffraction, ESI-TOF-MS, and X-ray photoelectron spectroscopy. Cu₁₄-8CH₃CN is the only copper cluster that has a virtually identical silver structural analog, i.e., Ag₁₄(C₂B₁₀H₁₀S₂)₆(CH₃CN)₈ (hereafter as Ag₁₄-8CH₃CN). Nevertheless, density functional theory calculations reveal that the electronic structure of Cu₁₄-8CH₃CN differs significantly from the superatom electronic configuration of Ag₁₄-8CH₃CN. Moreover, Cu₁₄-8CH₃CN shows room-temperature luminescence and good electrocatalytic activities in the ethanol oxidation reaction and detection of H₂O₂. This pair of unprecedented analogous molecular nanoscale systems offer an ideal platform to investigate the fundamental differences between copper and silver in terms of catalytic activity and optical properties.