Structural characterization and gas-phase studies of the [Ag₁₀H₈(L)₆]²⁺ nanocluster dication

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.

Using electrospray ionization‐tandem mass spectrometry to explore formation and gas‐phase chemistry of silver nanoclusters generated from the reaction of silver salts with NaBH4 in the presence of bis(diphenylarsino)methane

“…Further, the amine equivalent dppa is also able to produce the decanuclear Ag 10 species, which we were recently able to isolate and structurally characterize via X-ray crystallography and other methods. 23 These observations suggest that both the steric bulk provided by the phenyl groups and the binding strength of the ligand play a role in the stabilization of larger clusters and more importantly the nature of the types of nanoclusters formed. Finally, the BH 4 − containing clusters as mentioned above are entirely unique to the arsine ligand (dpam).…”

“…18,21 The other BH 4 − containing ions however were not previously observed where L = dppm, dppa, or dmpm and represent new cluster species for which their unimolecular gas-phase chemistry was investigated and is described below. [23][24][25] neither the arsenic equivalent (dpam) nor the less sterically bulky equivalent (dmpm) 26 are able to produce the larger homometallic silver hydride nanocluster. Further, the amine equivalent dppa is also able to produce the decanuclear Ag 10 species, which we were recently able to isolate and structurally characterize via X-ray crystallography and other methods.…”

“…[3][4][5][6] Electrospray ionization-mass spectrometry (ESI-MS) has proven to be a sensitive tool to study the growth of gold nanoclusters, [7][8][9][10][11][12][13][14][15] and we have used it to direct synthesis of a range of Ag and Cu nanoclusters (Scheme 1). [16][17][18][19][20][21][22][23] The nature of the metal, ligand, and reducing agent stoichiometries, solvent, and reaction temperature all play crucial roles in the types of clusters that are formed. While the structural motif "M 3 (μ 3 -H)" is common in the trinuclear complexes [M 3 (μ 3 -H)(μ 3 -BH 4 )(L) 3 ](BF 4 ) (where M = Ag or Cu, L = bis(diphenylphosphino)methane (Ph 2 P) 2 CH 2 = dppm or bis(diphenylphosphino)amine = (Ph 2 P) 2 NH = dppa), 18,19,21 [Ag 3 (μ 3 -H)(dppm) 3 ] (BF 4 ) 2 and [Ag 3 (μ 3 -H)(μ 3 -Cl)(dppm) 3 ](BF 4 ), 16,17 larger clusters are also observed.…”

“…Further, use of the ligand dppe (bis(diphenylphosphino)ethane = (Ph 2 P) 2 CH 2 CH 2 ) gave rise to a [Cu 18 (H) 16 (dppe) 6 ] + dication under similar synthetic conditions to that used to prepare [Cu 16 (H) 14 (dppa) 6 ] 2+ 22 . In contrast, when silver salts are used, the dications [Ag 10 (H) 8 (L) 6 ] 2+ (L = dppm or dppa) are formed, and in the case of [Ag 10 (H) 8 (dppa) 6 ](BF 4 ) 2 and [Ag 10 (H) 8 (dppa) 6 ](NO 3 ) 2 , these were structurally characterized via X‐ray crystallography 23–25 . Both dications have nearly identical structural features consisting of a Ag 10 scaffold with the atoms lying on vertices of a bicapped square antiprism 23 .…”

“…In contrast, when silver salts are used, the dications [Ag 10 (H) 8 (L) 6 ] 2+ (L = dppm or dppa) are formed, and in the case of [Ag 10 (H) 8 (dppa) 6 ](BF 4 ) 2 and [Ag 10 (H) 8 (dppa) 6 ](NO 3 ) 2 , these were structurally characterized via X‐ray crystallography 23–25 . Both dications have nearly identical structural features consisting of a Ag 10 scaffold with the atoms lying on vertices of a bicapped square antiprism 23 . Not all clusters are stable over various timeframes.…”