Ultracold water cluster anions

Abstract

Attachment of free electrons to water clusters embedded in helium droplets leads to watercluster anions (H2O)(n)(-) and (D2O)(n)(-) of size n >= 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.

Department

Physics

Publication Date

3-29-2008

Journal Title

Journal of the American Chemical Society

Publisher

AMER CHEMICAL SOC

Digital Object Identifier (DOI)

10.1021/ja075421w

Document Type

Article

Rights

© 2008 American Chemical Society

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