Abstract

We present what is to our knowledge the first femtosecond pump-probe studies on the solvated electron in liquid ammonia. Ultrafast near-infrared excitation of the electrons can be understood quantitatively in terms of a simple temperature jump which shifts within our time-resolution the electronic resonance by (5300 ± 500) cm⁻¹ into the mid-infrared spectral region. A subsequent blue-shift of the time-dependent absorption spectrum indicates the dynamics of electron cooling and occurs on a time scale of (200 ± 50) fs. Both pump pulse-induced temperature jump and cooling occur under shape stability of the electron resonance.

© 2002 Optical Society of America