Abstract

In this lecture we wish to report a study of triiodide ion photodissociation in ethanol solution using femtosecond time resolved absorption spectroscopy. Our results indicate that direct photocleavage of $I_{3^{-}}$ using 60 femtosecond UV pulses leads to a coherently vibrating ensemble of $I_{2^{-}}$ fragments within 300 fsec. The impulsive nature of the excitation also imposes vibrational coherence in the triiodide ions remaining in the ground state following absorption. The relaxation both of phase coherence and population is followed directly.

© 1992 The Author(s)