ULTRAFAST TRANSIENT-ABSORPTION SPECTROSCOPY OF THE AQUEOUS SOLVATED ELECTRON

We have performed the first direct pump-probe transient-absorption measurements on the near-infrared (IR) band of the equilibrated aqueous solvated electron. The pump pulse was centered at 780 nm. The absorption spectrum of the excited state is observed to be red-shifted relative to the ground-state absorption. The radiationless transition from the excited state to the ground state occurs with an average time constant of 550 +/- 170 fs. In observing a subpicosecond lifetime and red-shifted absorption for the excited p-states, these experiments are in accord with a growing body of experimental and theoretical work, serving to provide a consistent picture of the photophysics of the solvated electron.