Ultrafast transient-absorption spectroscopy of the aqueous solvated electron

Abstract

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.