FEMTOSECOND ABSORPTION ANISOTROPY OF THE AQUEOUS SOLVATED ELECTRON

Femtosecond near-infrared pump/visible probe absorption dichroism stud ies on the aqueous solvated electron are reported. Experiments perform ed with 300 fs time resolution demonstrate that the anisotropy of the transient absorption observed at 740, 800 and 860 nm is established co ncomitant with excitation and decays in approximate to 3 ps. This obse rvation is consistent with recent theoretical predictions (B.J. Schwar tz and P.J. Rossky, Phys. Rev, Letters (1994), submitted) and demonstr ates that anisotropic solvent fluctuations relax on the picosecond tim escale. However, the magnitude and spectral manifestations of the abso rption anisotropy are not consistent with theory.