The Synthesis, Bonding, and Transformation of a Ligand‐Protected Gold Nanohydride Cluster

Abstract

AbstractGold does not react with H2to form bulk hydrides. Here we report the synthesis and characterization of a gold nanohydride protected by diphosphine ligands, [Au22H4(dppo)6]2+[dppo=1,8‐bis(diphenylphosphino)octane]. The Au22core consists of two Au11units bonded by eight Au atoms not coordinated by the diphosphine ligands. The four H atoms are found to bridge the eight uncoordinated Au atoms at the interface. Each Au11unit can be viewed as a tetravalent superatom forming four delocalized Au‐H‐Au bonds, similar to the quadruple bond first discovered in the [Re2Cl8]2−inorganic cluster. The [Au22H4(dppo)6]2+nanohydride is found to lose H atoms over an extended time via H evolution (H2), proton (H+) and hydride (H−) releases. This complete repertoire of H‐related transformations suggests that the [Au22H4(dppo)6]2+nanohydride is a versatile model catalyst for understanding the mechanisms of chemical reactions involving hydrogen on the surface of gold nanoparticles.