Abstract

In liquid solution the dynamics of vibrational relaxation of diiodide generated through dissociative bond breakage of triiodide [1] and diiodide itself [2] has recently been studied in detail. In particular, the application of femtosecond optical pulses has proven to yield valuable information about time scales for thermalization and mean vibrational energies of the products directly after dissociation through the preparation and detection of vibrational superposition states [1]. We describe femtosecond pump-probe experiments on the dissociation reaction of triiodide in ethanol using 30 fs, 400 nm optical excitation pulses which are tuned to the red edge of the low energy absorption band of triiodide. Optical 50 fs pulses tunable from 450 to 950 nm cover the entire visible absorption spectrum of the diiodide product and are used for probing. The experimental data have been translated into vibrational product state distributions, thus giving additional unique information about the mechanism for photodissociation.

© 1996 Optical Society of America