title: Spectroscopic snapshots of the proton-transfer mechanism in water.
abstract: The Grotthuss mechanism explains the anomalously high proton mobility in water as a sequence of proton transfers along a hydrogen-bonded (H-bonded) network. However, the vibrational spectroscopic signatures of this process are masked by the diffuse nature of the key bands in bulk water. Here we report how the much simpler vibrational spectra of cold, composition-selected heavy water clusters, D+(D2O)n, can be exploited to capture clear markers that encode the collective reaction coordinate along the proton-transfer event. By complexing the solvated hydronium "Eigen" cluster [D3O+(D2O)3] with increasingly strong H-bond acceptor molecules (D2, N2, CO, and D2O), we are able to track the frequency of every O-D stretch vibration in the complex as the transferring hydron is incrementally pulled from the central hydronium to a neighboring water molecule.
authors.affiliation: Department of Chemistry, Yale University, New Haven, CT 06520, USA.
authors.forename: Conrad T
authors.initials: CT
authors.lastname: Wolke
authors.affiliation: Department of Chemistry, Yale University, New Haven, CT 06520, USA.|James Frank Institute and Department of Chemistry, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Fournier
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Dzugan
authors.affiliation: Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, 04103 Leipzig, Germany.|Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany.
authors.forename: Matias R
authors.initials: MR
authors.lastname: Fagiani
authors.affiliation: Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15620, USA.
authors.forename: Tuguldur T
authors.initials: TT
authors.lastname: Odbadrakh
authors.affiliation: Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, 04103 Leipzig, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Knorke
authors.affiliation: Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15620, USA. jordan@pitt.edu abmccoy@uw.edu knut.asmis@uni-leipzig.de mark.johnson@yale.edu.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Jordan
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA. jordan@pitt.edu abmccoy@uw.edu knut.asmis@uni-leipzig.de mark.johnson@yale.edu.|Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
authors.forename: Anne B
authors.initials: AB
authors.lastname: McCoy
authors.affiliation: Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, 04103 Leipzig, Germany. jordan@pitt.edu abmccoy@uw.edu knut.asmis@uni-leipzig.de mark.johnson@yale.edu.
authors.forename: Knut R
authors.initials: KR
authors.lastname: Asmis
authors.affiliation: Department of Chemistry, Yale University, New Haven, CT 06520, USA. jordan@pitt.edu abmccoy@uw.edu knut.asmis@uni-leipzig.de mark.johnson@yale.edu.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Johnson