title: Structure dynamics of the proton in liquid water probed with terahertz time-domain spectroscopy.
abstract: We study the hydration of protons in liquid water using terahertz time-domain spectroscopy and polarization-resolved femtosecond midinfrared pump-probe spectroscopy. We observe that the addition of protons leads to a very strong decrease of the dielectric response of liquid water that corresponds to 19+/-2 water molecules per dissolved proton. This depolarization results from water molecules ( approximately 4) that are irrotationally bound to the proton and from the motion of water (corresponding to the response of approximately 15 water molecules) involved in the transfer of the proton charge.
authors.affiliation: FOM Institute for Atomic and Molecular Physics [AMOLF], Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
authors.forename: K J
authors.initials: KJ
authors.lastname: Tielrooij
authors.forename: R L A
authors.initials: RL
authors.lastname: Timmer
authors.forename: H J
authors.initials: HJ
authors.lastname: Bakker
authors.forename: M
authors.initials: M
authors.lastname: Bonn
mesh_terms: D006860:Hydrogen Bonding; D008956:Models, Chemical; D013055:Spectrophotometry, Infrared / Q000379:methods*; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water