FEMTOSECOND ABSORPTION ANISOTROPY OF THE AQUEOUS SOLVATED ELECTRON

Femtosecond near-infrared pump/visible probe absorption dichroism studies on the aqueous solvated electron are reported. Experiments performed with 300 fs time resolution demonstrate that the anisotropy of the transient absorption observed at 740, 800 and 860 nm is established concomitant with excitation and decays in approximate to 3 ps. This observation is consistent with recent theoretical predictions (B.J. Schwartz and P.J. Rossky, Phys. Rev, Letters (1994), submitted) and demonstrates that anisotropic solvent fluctuations relax on the picosecond timescale. However, the magnitude and spectral manifestations of the absorption anisotropy are not consistent with theory.