title: Infrared spectroscopy of hydrated sulfate dianions.
abstract: We report the first infrared spectra of multiply-charged anions in the gas phase. The spectra of SO(4) (2-)(H(2)O)(n), with n=3-24, show four main bands assigned to two vibrations of the dianionic core, the water bending mode, and solvent libration. The triply degenerate SO(4) (2-) antisymmetric stretch vibration probes the local solvent symmetry, while the solvent librational band is sensitive to the hydrogen bonding network. The spectra and accompanying electronic structure calculations indicate a highly symmetric structure for the n=6 cluster and closure of the first solvation shell at n=12.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhou
authors.forename: Gabriele
authors.initials: G
authors.lastname: Santambrogio
authors.forename: Mathias
authors.initials: M
authors.lastname: Brümmer
authors.forename: David T
authors.initials: DT
authors.lastname: Moore
authors.forename: Ludger
authors.initials: L
authors.lastname: Wöste
authors.forename: Gerard
authors.initials: G
authors.lastname: Meijer
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Neumark
authors.forename: Knut R
authors.initials: KR
authors.lastname: Asmis