Femtosecond studies of electrons in liquids

Femtosecond time-resolved measurements were performed on the geminate recombination and solvation of electrons in liquids. The electrons were generated by multiphoton ionization in neat water and alkanes and by multiphoton detachment from Cl− and OH− ions in aqueous solution. For the neat liquids, the results are compared with the Onsager model of ion-pair recombination. An isotope effect is observed in the dynamics of both solvation and recombination in neat D2O relative to H2O. Studies with improved time resolution of electron solvation in neat water have measured the formation, decay, and absorption spectrum of the wet electron, i.e., the presolvated electron. By the discovery of an isosbestic wavelength, the formation of the wet electron is shown to involve two states; i.e., the transition is not continuous. The picture of the wet electron as an excited state of the solvated electron is presented. The differences in the solvation dynamics of electrons that are generated from neat water and from OH− and Cl− ions show that short-range molecular effects are important.

[1]  P. Rossky,et al.  The hydrated electron: quantum simulation of structure, spectroscopy, and dynamics , 1988 .

[2]  J. Hynes,et al.  Time-dependent fluorescence solvent shifts, dielectric friction, and nonequilibrium solvation in polar solvents , 1985 .

[3]  B. Berne,et al.  Behavior of the hydrated electron at different temperatures: structure and absorption spectrum , 1988 .

[4]  George E. Kimball,et al.  Diffusion-controlled reaction rates , 1949 .

[5]  Michael J. Blandamer,et al.  Theory and applications of charge-transfer-to-solvent spectra , 1970 .

[6]  F. H. Long,et al.  Femtosecond studies of electron-cation geminate recombination in water , 1989 .

[7]  F. H. Long,et al.  Femtosecond studies of electron-cation dynamics in neat water: The effects of isotope substitution , 1989 .

[8]  Harold L. Friedman,et al.  A Hydrodynamic Effect in the Rates of Diffusion-Controlled Reactions1 , 1966 .

[9]  L. Onsager.  Initial Recombination of Ions , 1938 .

[10]  P. Rossky,et al.  Electron localization in liquid water: A computer simulation study of microscopic trapping sites , 1986 .

[11]  W. Schmidt.  Electron mobility in nonpolar liquids: the effect of molecular structure, temperature, and electric field , 1977 .

[12]  G. Kenney-Wallace,et al.  Picosecond spectroscopy and solvation clusters. The dynamics of localizing electrons in polar fluids , 1982 .

[13]  B. Berne.  A self‐consistent theory of rotational diffusion , 1975 .

[14]  A. Mozumder.  Theory of Neutralization of an Isolated Ion Pair: Application of the Method of Prescribed Diffusion to Random Walk in a Coulomb Field , 1968 .

[15]  P. Rossky,et al.  Excess electron migration in liquid water , 1989 .

[16]  J. Hunt,et al.  Solvation time of the electron in polar liquids. Water and alcohols , 1975 .

[17]  O. Matsuoka,et al.  Relativistic well‐tempered Gaussian basis sets for helium through mercury , 1989 .

[18]  Lu,et al.  Femtosecond studies of the presolvated electron: An excited state of the solvated electron? , 1990, Physical review letters.

[19]  K. Eisenthal,et al.  Femtosecond study of geminate electron–hole recombination in neat alkanes , 1988 .

[20]  Graham R. Fleming,et al.  Theory of the time development of the Stokes shift in polar media , 1984 .

[21]  Alan E. Johnson,et al.  Femtosecond microscopic solvation dynamics of aqueous solutions , 1988 .

[22]  J. Boag,et al.  ABSORPTION SPECTRUM OF THE HYDRATED ELECTRON IN WATER AND IN AQUEOUS SOLUTIONS , 1962 .

[23]  M. Washio,et al.  Picosecond pulse radiolysis studies on geminate ion recombination in saturated hydrocarbon , 1983 .

[24]  C. Braun,et al.  Picosecond measurements of geminate charge pair recombination in photoionized liquids , 1985 .

[25]  Y. Tsvetkov,et al.  The thermalization length of low-energy electrons determined by nanosecond photoemission into aqueous electrolyte solutions , 1985 .

[26]  S. Mukamel,et al.  Molecular theory of solvation and dielectric response in polar fluids , 1987 .

[27]  P. Clifford,et al.  Stochastic models of diffusion-controlled ionic reactions-induced spurs. 2. Low-permittivity solvents , 1989 .

[28]  Schnitker,et al.  A priori calculation of the optical absorption spectrum of the hydrated electron. , 1988, Physical review letters.

[29]  J. Klafter,et al.  Solvation dynamics in polar liquids , 1988 .

[30]  A. O. Allen,et al.  Free‐Ion Yields in Sundry Irradiated Liquids , 1970 .

[31]  P. Wolynes,et al.  Smoluchowski–Vlasov theory of charge solvation dynamics , 1983 .

[32]  D. Kivelson,et al.  Theory of time‐dependent polarization about an ion in an isotropic liquid , 1987 .

[33]  K. Schmidt,et al.  Absorption spectrum of eaq- in the temperature range -4 to 390.deg. , 1971 .

[34]  Martin,et al.  Excess electrons in liquid water: First evidence of a prehydrated state with femtosecond lifetime. , 1987, Physical review letters.

[35]  J. Jortner,et al.  CAGE EFFECTS AND SCAVENGING MECHANISMS IN THE PHOTOCHEMISTRY OF THE IODIDE ION IN AQUEOUS SOLUTIONS , 1962 .

[36]  J. Noolandi,et al.  Solution of the Smoluchowski equation with a Coulomb potential. I. General results , 1978 .

[37]  J. Rabani,et al.  FORMATION OF THE HYDRATED ELECTRON IN THE FLASH PHOTOLYSIS OF AQUEOUS SOLUTIONS1 , 1963 .

[38]  J. Wiesenfeld,et al.  Dynamics of electron solvation in liquid water , 1980 .

[39]  A. K. Pikaev.  The Solvated Electron in Radiation Chemistry , 1971 .

[40]  J. Hynes,et al.  Short range caging effects for reactions in solution. II. Escape probability and time dependent reactivity , 1979 .

[41]  M. Tachiya.  General method for calculating the escape probability in diffusion‐controlled reactions , 1978 .

[42]  U. Landman,et al.  Relaxation dynamics following transition of solvated electrons , 1989 .

[43]  R. Street.  Electronic Processes in Noncrystalline Materials , 1973 .

[44]  T. Goulet,et al.  Thermalization distances and times for subexcitation electrons in solid water , 1988 .

[45]  F. H. Long,et al.  Femtosecond Studies of Electrons in Water , 1990, Ultrafast Phenomena.

[46]  R. Marcus,et al.  Dielectric relaxation and intramolecular electron transfers , 1986 .

[47]  F. W. Lampe,et al.  REACTIONS OF GASEOUS IONS. IV. WATER , 1957 .

[48]  R. Marcus,et al.  Electron transfers in chemistry and biology , 1985 .

[49]  F. H. Long,et al.  Femtosecond studies of electron photodetachment of simple ions in liquid water: Solvation and geminate recombination dynamics , 1989 .

[50]  A. Nichols,et al.  Polar solvent relaxation: The mean spherical approximation approach , 1988 .

[51]  F. Dainton,et al.  Primary processes in the photolysis of the iodide ion in aqueous solution , 1965, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[52]  W. P. Helman.  The quenching of alkane fluorescence by CCl4 measured by nanosecond decay time techniques , 1972 .

[53]  L. Grossweiner,et al.  THE KINETICS OF THE DIHALIDE IONS FROM THE FLASH PHOTOLYSIS OF AQUEOUS ALKALI HALIDE SOLUTIONS , 1957 .

[54]  Farhataziz,et al.  Radiation Chemistry: Principles and Applications , 1987 .

[55]  S. Tagawa,et al.  Study of geminate ion recombination in a solute-solvent system by using picosecond pulse radiolysis , 1987 .

[56]  P. Wolynes.  Linearized microscopic theories of nonequilibrium solvation , 1987 .

[57]  M. Maroncelli,et al.  Picosecond solvation dynamics of coumarin 153: The importance of molecular aspects of solvation , 1987 .

[58]  C. Jonah.  Decay of geminate ions in hexanes , 1983 .

[59]  C. Braun,et al.  Picosecond transient absorption measurements of geminate electron-cation recombination , 1987 .

[60]  G. Freeman,et al.  Electron Mobilities and Ranges in Liquid C1–C3 Hydrocarbons and in Xenon: Effects of Temperature and Field Strength , 1974 .

[61]  A. C. Chernovitz,et al.  Isotopic dependence of recombination kinetics in water , 1988 .

[62]  K. Eisenthal,et al.  Picosecond laser studies of electron solvation in alcohols , 1980 .

[63]  Raymond M. Fuoss,et al.  Theory of dielectrics. , 1949 .