La chimie ultra-rapide capturée en temps réel

This paper presents two results that illustrate the remarkable ability of ultrafast transient absorption and Raman scattering spectroscopic techniquesto provide detailed information on the mechanism of photoinduced reactions. In a first example, the analysis of the protonation by H2O of a strongly basic anion radical produced via photoreduction shows that this reactionis governed by the solvation dynamics of the OH- ion that is released in the proton transfer and provides information on the hydration structure of this ion. The second example is related to the characterization of the ultrafast kinetics of photocommutation in bistable photochromic compounds, which is a determinant parameter for applications in photonics.