Atomic Gold Ions Clustered with Noble Gases: Helium, Neon, Argon, Krypton, and Xenon
Abstract
High-resolution mass spectra of helium droplets doped with gold and ionized by electrons reveal HenAu+ cluster ions. Additional doping with heavy noble gases results in NenAu+, ArnAu+, KrnAu+, and XenAu+ cluster ions. The high stability predicted for covalently bonded Ar2Au+, Kr2Au+, and Xe2Au+ is reflected in their relatively high abundance. Surprisingly, the abundance of Ne2Au+, which is predicted to have zero covalent bonding character and no enhanced stability, features a local maximum, too. The predicted size and structure of complete solvation shells surrounding ions with essentially nondirectional bonding depends primarily on the ratio σ* of the ion–ligand versus the ligand–ligand distance. For Au+ solvated in helium and neon, the ratio σ* is slightly below 1, favoring icosahedral packing in agreement with a maximum observed in the corresponding abundance distributions at n = 12. HenAu+ appears to adopt two additional solvation shells of Ih symmetry, containing 20 and 12 atoms, respectively. For ArnAu+, with σ* ≈ 0.67, one would expect a solvation shell of octahedral symmetry, in agreement with an enhanced ion abundance at n = 6. Another anomaly in the ion abundance at Ar9Au+ matches a local maximum in its computed dissociation energy.
Department
Physics
Publication Date
10-17-2019
Journal Title
The Journal of Physical Chemistry A
Publisher
ACS Publications
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
P. Martini, L. Kranabetter, M. Goulart, B. Rasul, M. Gatchell, P. Scheier, O. Echt, Atomic Gold Ions Clustered with Noble Gases: Helium, Neon, Argon, Krypton, and Xenon, J. Phys. Chem. A 123 (2019) 9505-9513, DOI 10.1021/acs.jpca.9b06715, Oct 2019.