Temperature-dependent studies of solvated electrons in liquid water with two and three femtosecond pulse sequences
Two and three pulse sequences with an experimental time resolution of about 100 fs have been used to unravel the dynamics of solvated electrons in water at different temperatures. Both, geminate recombination and relaxation of the absorption spectrum can be distinguished using these pulse sequences. The relaxation process has been analysed applying shape stability of the absorption spectrum on an ultrafast time scale. A rigorous analysis of our data leads to strong evidence that solvated electrons in pure water are formed, after a delay, within the first few hundred fs after 9.32 eV photon absorption. Transferring optical sum rules (moment analysis of the absorption spectrum) to the ultrafast dynamics of solvated electrons we conclude that electronic ground state dynamics dominate the relaxation of solvated electrons.