Instantaneous Product Anisotropies in the fs-Photolysis of Triiodide

Abstract

Multiple-pulse fs-polarization experiments are presented in order to explore exit channel dynamics in the femtosecond photodissociation of triiodide ions in ethanol solution. The recoil dynamics can be modeled quite accurately with a simple classical description of motion along the reaction coordinate. The corresponding instantaneous anisotropies induced in the system exhibit coherent contributions that arise from degeneracies in the electronic structure at very early stages of the bond breakage. The coherence decay reflects dephasing and lifting of the degeneracy as the fragments separate.