Time-resolved observation of the Eigen cation in liquid water.
Experimental observation and time relaxation measurement of the hydrated proton Eigen form [H(3)O(+)(H(2)O)(3)] are presented here. Vibrational time-resolved spectroscopy is used with an original method of investigating the proton excess in water. The anharmonicity of the time-resolved spectra is characteristic of the Eigen-type proton geometry. Proton relaxation occurs in less than 200 fs. A calculation of the potential energy confirms the experimental result and the Eigen cation lifetime is in good agreement with previous molecular dynamics simulations.
Amir
Wafa
W
Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, 91128 Palaiseau, France.
Gallot
Guilhem
G
Hache
François
F
Bratos
S
S
Leicknam
J-C
JC
Vuilleumier
R
R
D002412:Cations; D002627:Chemistry, Physical / Q000379:methods*; D015233:Models, Statistical; D008968:Molecular Conformation; D016011:Normal Distribution; D010100:Oxygen / Q000737:chemistry; D011522:Protons; D012997:Solvents; D013055:Spectrophotometry, Infrared; D013057:Spectrum Analysis / Q000379:methods*; D013997:Time Factors; D014867:Water / Q000737:chemistry
D002412:Cations; D011522:Protons; D012997:Solvents; D014867:Water; D010100:Oxygen