High‐resolution mass spectra of helium nanodroplets doped with hydrogen or deuterium reveal that copious amounts of helium can be bound to H+, H2+, H3+, and larger hydrogen‐cluster ions. All conceivable HenHx+ stoichiometries are identified if their mass is below the limit of ≈120 u set by the resolution of the spectrometer. Anomalies in the ion yields of HenHx+ for x=1, 2, or 3, and n≤30 reveal particularly stable cluster ions. Our results for HenH1+ are consistent with conclusions drawn from previous experimental and theoretical studies which were limited to smaller cluster ions. The HenH3+ series exhibits a pronounced anomaly at n=12 which was outside the reliable range of earlier experiments. Contrary to findings reported for other diatomic dopant molecules, the monomer ion (i.e. H2+) retains helium with much greater efficiency than hydrogen‐cluster ions.
Digital Object Identifier (DOI)
P. Bartl, C. Leidlmair, S. Denifl, P. Scheier, and O. Echt, Cationic Complexes of Hydrogen with Helium, ChemPhysChem 14 (2013) 227-232, DOI: 10.1002/cphc.201200664, Jan 2013