Fission barriers of doubly charged silver clusters

Abstract

The monomer evaporation energies and fission barriers of doubly charged silver cluster ions in the size range 9 ≤ n ≤ 25 are measured by collision induced dissociation. They are compared to the dissociation energies of singly charged silver clusters. A macroscopic liquid drop model combined with empirical microscopic corrections successfully describes the measured fission barriers.PACS. 36.40.Qv Stability and fragmentation of clusters -36.40.Wa Charged clusters

Doubly Charged Silver Clusters Stabilized by Tryptophan: Ag42+ as an Optical Marker for Monitoring Particle Growth

“…This is not the case for smaller Ag species. As previously observed, Ag 3 bound to tryptophan in TrpAg 3 + is singly charged. [11] The even smaller species Ag 2 2+ is not bound as a consequence of the electrostatic repulsion and the absence of valence electrons.…”

“…) are not stable for n < 7, [3] stabilization can be provided by the environment. Indeed, the attachment of protective ligands such as complex chemical [4] or biomolecular [5,6] templates was used to stabilize multiply charged clusters.…”

“…Small multiply charged systems, in particular silver clusters, have been studied extensively in the gas phase. [2,3] Although isolated metal clusters with double charge (e.g. Ag n…”

Gas-phase dissociation pathways of multiply charged peptide clusters

“…Brechignac et al explained this result by suggesting that instead of continuing to increase with increasing cluster size, the fission barrier height evolves in such a way as to stay competitive with evaporation as the cluster size increases [38]. The interpretation of the LE cluster dissociation results would be greatly facilitated by the measurement of the activation energies of evaporation and fission for these clusters as has been reported for multiply charged silver clusters [62].…”

“…Brechignac et al explained this result by suggesting that instead of continuing to increase with increasing cluster size, the fission barrier height evolves in such a way as to stay competitive with evaporation as the cluster size increases [38]. The interpretation of the LE cluster dissociation results would be greatly facilitated by the measurement of the activation energies of evaporation and fission for these clusters as has been reported for multiply charged silver clusters [62].The liquid-drop model has been used previously to describe the asymmetric dissociation and charge partitioning of tetrameric streptavidin [30]. Homogeneous protein complexes of 2-6 monomer units have been shown to dissociate primarily by the ejection of a single subunit that removes 30 -50% of the total charge of the complex [29][30][31][32][33]35].…”