Ultrastable hydrido gold nanoclusters with the protection of phosphines†
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 (1H) and [Au20(PPh3)12H2(2-COOH-PhS)](PF6)3 (2H). 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.