title: Hydrogen bond breaking dynamics of the water trimer in the translational and librational band region of liquid water.
abstract: The effect of exciting each of the three classes of intermolecular vibrations on the hydrogen bond lifetime (tau(H)) of the isolated water trimer is investigated by far-infrared laser spectroscopy. Single excitation of a librational vibration decreases tau(H) by 3 orders of magnitude to tau(H) = 1-6 ps, comparable to the time scale of a number of important bulk water dynamical relaxation processes. In contrast, excitation of translational or torsional vibrations has no significant effect (tau(H) = 1-2 ns). Although such a dependence of tau(H) on intermolecular motions has also been proposed for liquid water via computer simulations, these are the first experiments that provide a detailed molecular picture of the respective motions without extensive interpretation.
authors: Department of Chemistry, University of California, Berkeley, CA 94720, USA.
authors: F N
authors: FN
authors: Keutsch
authors: R S
authors: RS
authors: Fellers
authors: M G
authors: MG
authors: Brown
authors: M R
authors: MR
authors: Viant
authors: P B
authors: PB
authors: Petersen
authors: R J
authors: RJ
authors: Saykally
mesh_terms: D006860:Hydrogen Bonding; D007834:Lasers; D008958:Models, Molecular; D008968:Molecular Conformation; D013055:Spectrophotometry, Infrared; D014732:Vibration; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water