Please use this identifier to cite or link to this item:
Title: Electron impact ionization of water-doped superfluid helium nanodroplets: observation of He (H2O)+n clusters
Authors: Yang, Shengfu
Brereton, Scott M.
Nandhra, Satvinder
Ellis, Andrew M.
Shang, Bo
Yuan, Lan-Feng
Yang, Jinlong
First Published: 2-Oct-2007
Publisher: American Institute of Physics (AIP)
Citation: Journal of Chemical Physics, 2007, 127(13), 4303.
Abstract: Electron impact mass spectra have been recorded for helium nanodroplets containing water clusters. In addition to identification of both H+(H2O)n and (H2O)n+ ions in the gas phase, additional peaks are observed which are assigned to He(H2O)n+ clusters for up to n = 27. No clusters are detected with more than one helium atom attached. The interpretation of these findings is that quenching of (H2O)n+ by the surrounding helium can cool the cluster to the point where not only is fragmentation to H+(H2O)m (where m ⩽ n−1) avoided, but also, in some cases, a helium atom can remain attached to the cluster ion as it escapes into the gas phase. Ab initio calculations suggest that the first step after ionization is the rapid formation of distinct H3O+ and OH units within the (H2O)n+ cluster. To explain the formation and survival of He(H2O)n+ clusters through to detection, the H3O+ is assumed to be located at the surface of the cluster with a dangling O–H bond to which a single helium atom can attach via a charge-induced dipole interaction. This study suggests that, like H+(H2O)n ions, the preferential location for the positive charge in large (H2O)n+ clusters is on the surface rather than as a solvated ion in the interior of the cluster.
DOI Link: 10.1063/1.2772624
ISSN: 0021-9606
eISSN: 1089-7690
Version: Publisher version
Status: Peer reviewed
Type: Article
Rights: Copyright 2007 American Institute of Physics. Deposited with reference to the publisher's archiving policy available on the SHERPA/RoMEO website. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Chemical Physics, 2007, 127(13), 4303 and may be found at
Appears in Collections:Published Articles, Dept. of Chemistry

Files in This Item:
File Description SizeFormat 
JChemPhys_127_134303.pdf176.92 kBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.