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MO: Fachverband Molekülphysik
MO 1: Cluster
MO 1.6: Talk
Monday, March 18, 2013, 12:15–12:30, F 102
Infrared photo dissociation spectroscopy of perhalogenated closo-dodecaborate clusters [B12X12]2− (X=Br, I) — Matias R. Fagiani1, •Tim Esser1, Jonas Warneke2, Nadja Heine1, and Knut R. Asmis1 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany — 2Institute for Applied and Physical Chemistry, University of Bremen, Leobener Strasse, NW2, 28359 Bremen, Germany
Closo-dodecaborates are important materials and subject to recent research on ionic liquids, lithium ion batteries and stabilization of reactive cations. Recent collision-induced dissociation studies by Warneke et al. showed complex fragmentation patters for the perhalogenated dianions [B12X12]2− (X=F, Cl, Br, I). The brominated cluster [B12Br12]2− showed a higher tendency to fragment under loss of an X− anion then the iodinated cluster [B12I12]2− wich is more likely to loose a X• radical. In order to characterize the structure of these ions we performed infared photodissociation (IRPD) experiments. To this end, dianions are produced by ion spray, mass-selected by a quadrupole mass filter and accumulated in a cryogenically cooled ion trap which is filled with a buffer gas. The ion trap serves for accumulation, thermalization and messenger tagging of the ions. After extraction from the ion trap the ion/messenger clusters are exposed to IR radiation. IRPD spectra of [B12Br12]2− and [B12I12]2−, measured in the range from 700 to 1500 cm−1, are presented and assigned on the basis of electronic structure calculations.