title: Formation of dianions in helium nanodroplets.
abstract: The formation of dianions in helium nanodroplets is reported for the first time. The fullerene cluster dianions (C60)n(2-) and (C70)n(2-) were observed by mass spectrometry for n≥5 when helium droplets containing the appropriate fullerene were subjected to electron impact at approximately 22 eV. A new mechanism for dianion formation is described, which involves a two-electron transfer from the metastable He(-) ion. As well as the prospect of studying other dianions at low temperature using helium nanodroplets, this work opens up the possibility of a wider investigation of the chemistry of He(-), a new electron-donating reagent.
authors.affiliation: Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, 6020 Innsbruck (Austria).
authors.forename: Andreas
authors.initials: A
authors.lastname: Mauracher
authors.forename: Matthias
authors.initials: M
authors.lastname: Daxner
authors.forename: Stefan E
authors.initials: SE
authors.lastname: Huber
authors.forename: Johannes
authors.initials: J
authors.lastname: Postler
authors.forename: Michael
authors.initials: M
authors.lastname: Renzler
authors.forename: Stephan
authors.initials: S
authors.lastname: Denifl
authors.forename: Paul
authors.initials: P
authors.lastname: Scheier
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Ellis
keywords: density functional calculations; doubly charged anions; electron transfer; fullerenes; helium nanodroplets