Structural characterization and gas-phase studies of the [Ag10H8(L)6]2+ nanocluster dication. Issue 47 (25th November 2019)

• Record Type: Journal Article
• Authors: Ma, Howard Z.; McKay, Alasdair I.; Mravak, Antonija; Scholz, Michael S.; White, Jonathan M.; Mulder, Roger J.; Bieske, Evan J.; Bonačić-Koutecký, Vlasta; O'Hair, Richard A. J.
• Is Part Of: Nanoscale. Volume 11:Issue 47(2019)
• Page Start: 22880
• Page End: 22889
• Publication Date: 2019-11-25
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c9nr08321a
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : The structure of a large dicationic silver hydride nanocluster was determined by X-ray crystallography. Pathways to the gas-phase liberation of hydrogen have been identified. Abstract : The reactions between silver salts and borohydrides produce a rich set of products that range from discrete mononuclear compounds through to silver nanoparticles and colloids. Previous studies using electrospray ionization mass spectrometry (ESI-MS) to track the cationic products in solutions containing sodium borohydride, silver(i ) tetrafluoroborate and the bisphosphine ligands, L, bis(diphenylphosphino)methane (dppm) and bis(diphenylphosphino)amine (dppa) have identified the dications [Ag10 H8 (L)6 ] 2+ . Here we isolate and structurally characterize [Ag10 H8 (dppa)6 ](BF4 )2, and [Ag10 H8 (dppa)6 ](NO3 )2 via X-ray crystallography. Both dications have nearly identical structural features consisting of a Ag10 scaffold with the atoms lying on vertices of a bicapped square antiprism. DFT calculations were carried out to suggest potential sites for the hydrides. Ion-mobility mass spectrometry experiments revealed that [Ag10 H8 (dppa)6 ] 2+ and [Ag10 H8 (dppm)6 ] 2+ have similar collision cross sections, while multistage mass spectrometry experiments were used to compare their unimolecular gas-phase chemistry. Although the same initial sequential ligand loss followed by cluster fission and H2 evolution is observed, the more acidic N–H of the dppa provides a more labile H for H2 loss and H/D scrambling processes as revealed by isotope labelled experiments.