title: Thermochemistry of the Reaction of SF6 with Gas-Phase Hydrated Electrons: A Benchmark for Nanocalorimetry.
abstract: The reaction of sulfur hexafluoride with gas-phase hydrated electrons (H2O)n(-), n ≈ 60-130, is investigated at temperatures T = 140-300 K by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. SF6 reacts with a temperature-independent rate of 3.0 ± 1.0 × 10(-10) cm(3) s(-1) via exclusive formation of the hydrated F(-) anion and the SF5(•) radical, which evaporates from the cluster. Nanocalorimetry yields a reaction enthalpy of ΔHR,298K = 234 ± 24 kJ mol(-1). Combined with literature thermochemical data from bulk aqueous solution, these result in an F5S-F bond dissociation enthalpy of ΔH298K = 455 ± 24 kJ mol(-1), in excellent agreement with all high-level quantum chemical calculations in the literature. A combination with gas-phase literature thermochemistry also yields an experimental value for the electron affinity of SF5(•), EA(SF5(•)) = 4.27 ± 0.25 eV.
authors.affiliation: Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel , Olshausenstrasse 40, 24098 Kiel, Germany.|Institut für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck , Technikerstrasse 25, 6020 Innsbruck, Austria.
authors.forename: Amou
authors.initials: A
authors.lastname: Akhgarnusch
authors.affiliation: Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel , Olshausenstrasse 40, 24098 Kiel, Germany.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Höckendorf
authors.affiliation: Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel , Olshausenstrasse 40, 24098 Kiel, Germany.|Institut für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck , Technikerstrasse 25, 6020 Innsbruck, Austria.
authors.forename: Martin K
authors.initials: MK
authors.lastname: Beyer