Publications [#260689] of Volker Blum

Journal Articles

1. Heine, N; Fagiani, MR; Rossi, M; Wende, T; Berden, G; Blum, V; Asmis, KR, Isomer-Selective Detection of Hydrogen-Bond Vibrations in the Protonated Water Hexamer, Journal of the American Chemical Society, vol. 135 no. 22 (2013), pp. 8266-8273, American Chemical Society [doi]
   (last updated on 2023/06/01)

   Abstract:
   The properties of hydrogen ions in aqueous solution are governed by the ability of water to incorporate ions in a dynamical hydrogen bond network, characterized by a structural variability that has complicated the development of a consistent molecular level description of H(+)(aq). Isolated protonated water clusters, H(+)(H2O)n, serve as finite model systems for H(+)(aq), which are amenable to highly sensitive and selective gas phase spectroscopic techniques. Here, we isolate and assign the infrared (IR) signatures of the Zundel-type and Eigen-type isomers of H(+)(H2O)6, the smallest protonated water cluster for which both of these characteristic binding motifs coexist, down into the terahertz spectral region. We use isomer-selective double-resonance population labeling spectroscopy on messenger-tagged H(+)(H2O)6·H2 complexes from 260 to 3900 cm(-1). Ab initio molecular dynamics calculations qualitatively recover the IR spectra of the two isomers and allow attributing the increased width of IR bands associated with H-bonded moieties to anharmonicities rather than excited state lifetime broadening. Characteristic hydrogen-bond stretching bands are observed below 400 cm(-1).