Femtosecond solvation dynamics of solvated electrons in neat water

• Published in: Chemical physics letters Vol. 317; no. 1; pp. 13 - 22
• Main Authors: Assel, M, Laenen, R, Laubereau, A
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2000
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/S0009-2614(99)01369-X

We report on transient pump–probe spectroscopy of equilibrated solvated electrons in neat water in the visible/near-infrared using femtosecond pulses and polarization resolution. By excitation in the blue wing of the absorption band the e − are promoted from the 1s ground state to the highest of the 2p sub-states. First rapid solvent relaxation and/or population redistribution among the excited 2p sub-states is followed by the population of a modified excited state p′ with a lifetime of τ 2=190±40 fs. The second intermediate is assigned to a modified ground state s′′ while subsequent ground state recovery proceeds within τ 3=0.9±0.15 ps. The negligible net anisotropy <0.01 of the probe absorption indicates that the observed distribution of solvent cavities of hydrated electrons is close to spherical symmetry.