Site-specific vibrational spectral signatures of water molecules in the magic H 3 O + (H 2 O) 20 and Cs + (H 2 O) 20 clusters
- Sterling Chemistry Laboratory, Department of Chemistry, Yale University, New Haven, CT 06520,
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, D-14195 Berlin, Germany, and
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, D-04103 Leipzig, Germany
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, D-14195 Berlin, Germany, and, Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, D-04103 Leipzig, Germany
Here, theoretical models of proton hydration with tens of water molecules indicate that the excess proton is embedded on the surface of clathrate-like cage structures with one or two water molecules in the interior. The evidence for these structures has been indirect, however, because the experimental spectra in the critical H-bonding region of the OH stretching vibrations have been too diffuse to provide band patterns that distinguish between candidate structures predicted theoretically. Here we exploit the slow cooling afforded by cryogenic ion trapping, along with isotopic substitution, to quench water clusters attached to the H3O+ and Cs+ ions into structures that yield well-resolved vibrational bands over the entire 215- to 3,800-cm-1 range. The magic H3O+(H2O)20 cluster yields particularly clear spectral signatures that can, with the aid of ab initio predictions, be traced to specific classes of network sites in the predicted pentagonal dodecahedron H-bonded cage with the hydronium ion residing on the surface.
- Research Organization:
- Yale Univ., New Haven, CT (United States)
- Sponsoring Organization:
- USDOE; National Science Foundation (NSF); US Air Force; US Department of Defense (DOD)
- Grant/Contract Number:
- FG02-06ER15800; CHE-1213634; FA9550-13-1-0007; CNS 08-21132
- OSTI ID:
- 1235099
- Alternate ID(s):
- OSTI ID: 1348391
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Vol. 111 Journal Issue: 51; ISSN 0027-8424
- Publisher:
- Proceedings of the National Academy of SciencesCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Size-Dependent Onset of Nitric Acid Dissociation in Cs+·(HNO3)(H2O)n=0–11 Clusters at 20 K
Characterization of the primary hydration shell of the hydroxide ion with H2 tagging vibrational spectroscopy of the OH- ∙ (H2O)n=2,3 and OD- ∙ (D2O)n=2,3 clusters