title: Ultracold water cluster anions.
abstract: Attachment of free electrons to water clusters embedded in helium droplets leads to water-cluster anions (H2O)n(-) and (D2O)n(-) of size n > or = 2. Small water-cluster anions bind to up to 10 helium atoms, providing compelling evidence for the low temperature of these complexes, but the most abundant species are bare cluster anions. In contrast to previous experiments on bare water clusters, which showed very pronounced magic and anti-magic anion sizes below n = 12, the presently observed size distributions vary much more smoothly, and all sizes are easily observed. Noticeable differences are also observed in the stoichiometry of fragment anions formed upon dissociative electron attachment and the energy dependence of their yield. Spectroscopic characterization of these ultracold water-cluster anions promises to unravel the relevance of metastable configurations in experiments and the nature of the still controversial bonding sites for the excess electron in small water-cluster anions.
authors: Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität, Technikerstrasse 25, A-6020 Innsbruck, Austria.
authors: Fabio
authors: F
authors: Zappa
authors: Stephan
authors: S
authors: Denifl
authors: Ingo
authors: I
authors: Mähr
authors: Arntraud
authors: A
authors: Bacher
authors: Olof
authors: O
authors: Echt
authors: Tilmann D
authors: TD
authors: Märk
authors: Paul
authors: P
authors: Scheier
mesh_terms: D000838:Anions / Q000737:chemistry*; D003198:Computer Simulation; D003903:Deuterium / Q000737:chemistry; D006371:Helium / Q000737:chemistry*; D006860:Hydrogen Bonding; D013058:Mass Spectrometry; D008968:Molecular Conformation; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D000838:Anions; D012997:Solvents; D014867:Water; D006371:Helium; D003903:Deuterium