Ultrastable hydrido gold nanoclusters with the protection of phosphines

Abstract

The identification of hydride(s) in gold nanoclusters is a challenging task, due to the instability of gold nanoclusters containing hydrides. Herein, we report two ultrastable hydrido gold nanoclusters protected by phosphine ligands: [Au₂₀(PPh₃)₁₂H₃](SbF₆)₃ (1_H) and [Au₂₀(PPh₃)₁₂H₂(2-COOH-PhS)](PF₆)₃ (2_H). The presence of hydrides in gold(0)–gold(I) nanoclusters is clearly demonstrated by ESI mass spectrometry and NMR spectroscopy. Single crystal structural determination reveals that both nanoclusters have an unprecedented Au₂₀ core consisting of a Au₉ unit and a Au₁₁ unit. Such cores derived from the connection of different basic units are important for understanding the evolution and stability of metal nanoclusters. The hydride (H⁻) was also verified by a charge distribution calculation.