Dynamics of solvation of an excess electron

We have utilized the techniques of picosecond spectroscopy to study the localization of an excess electron in water. Quasifree electrons were generated by the photoionization of the ferrocyanide anion in aqueous solutions at 2650 A. Time resolved absorption of the localized electron was monitored continuously from 1.06 ju to 5300 A, while time and energy resolved absorption was monitored in the range 3100-9000 A by a broad continuum of picosecond duration. Optical absorption of the initially localized electron in the infrared (1.06 /x) is observed within 2 psec after the generation of the quasifree electron. The optical absorption band evolves in time, shifting from lower to higher energies, and the "normal" absorption of the hydrated electron is developed in ~4 psec.