Time-resolved excited state energetics of the solvated electron in sodium-doped water clusters.

The energetics and dynamics of the first electronically excited state of solvated electron in sodium-doped water clusters has been studied, by means of time-resolved electron spectra created in a pump-probe fs-laser experiment. The Na ··· (H2O)n clusters were excited by pulses at a wavelength of 795 nm, while ionization was achieved at a wavelength of 398 nm, and the overall cross-correlation fwhm was about 50 fs. Mass-resolved electron spectra were taken using photoelectron-photoion coincidence (PEPICO) spectroscopy for cluster sizes ranging from n = 1 up to 22. The electron spectra give new insights into the dynamics of the excited state of solvated electrons in Na ··· (H2O)n clusters. These dynamics are compared to known results for water cluster anions. In both cases, the observed dynamics are a combination of solvent rearrangement and internal energy conversion.