Delocalizing electrons in water with light

Experimental information on the spatial extent of the putative p and conduction band states of the hydrated electron (e(eq)) has been obtained by monitoring and controlling the electron/hole spatial separation of a photogenerated eq/hole pair using a femtosecond laser pulse sequence. Optical excitation of e(eq) with two photons is observed to dramatically alter its spatial distribution and geminate recombination yield with the hole. One-photon excitation, in contrast, has no effect on the spatial distribution. The results strongly confirm theoretical predictions on the size and location of excited states of e(eq).