Objectif Atomic ions in liquids are of vital importance in almost all biological and chemical processes. In addition, they can serve as simple model systems for understanding the details of hydration and solvation dynamics in liquids. Solvation dynamics involves changes of the solvent shell structure around a solute upon electronic changes of the solute.It is therefore at the core of condensed phase chemistry and biology. Femtosecond optical pump-probe spectroscopy has been a revolutionary tool for observing real time motion of simple molecular systems, with its inherent ability to temporally resolve phenomena at the fundamental timescales of nuclear and electronic motion.However, for a more complete description of the dynamics of even more complex systems, which would also include structural determination, we propose a novel approach, which combines ultrafast optical and X-ray spectroscopies in a pump-probe scheme. Such a technique will allow a direct visualization of the structural changes of the solvent shell around atomic ions in real time.In this pump-probe scheme an ultrafast laser pulse excites the solute, while another optical or X-ray pulse takes snapshots of the changes resulting from the excitation as a function of time after excitation. In this technique, the picosecond X-ray pulses are produced in a synchrotron and the detected signal is the X-ray absorption of the solute.The detected signal carries information about the electronic structure changes of the solute (via X-ray Absorption Near-Edge Structure), as well as the geometric changes of the solvent shell (via Extended Xray Absorption Fine Structure).Using time-resolved X-ray absorption spectroscopy in this configuration we propose to study the solvation process around halogen anions and metallic cat ions. With this approach we hope to capture, for the first time, the structural details of the solvation process, and to gain insight into the hydration process and liquid state. Champ scientifique natural sciencesphysical sciencesopticsspectroscopyabsorption spectroscopynatural sciencesphysical sciencesopticslaser physicsultrafast lasersnatural scienceschemical sciencesinorganic chemistryhalogensnatural scienceschemical sciencesorganic chemistryalcohols Mots‑clés Solvation dynamics X-ray absorption alcohols atomic ions picosecond pump-probe spectroscopy structure ultrashort lasers water Programme(s) FP6-MOBILITY - Human resources and Mobility in the specific programme for research, technological development and demonstration "Structuring the European Research Area" under the Sixth Framework Programme 2002-2006 Thème(s) MOBILITY-4.2 - Marie Curie International Reintegration Grants (IRG) Appel à propositions FP6-2002-MOBILITY-12 Voir d’autres projets de cet appel Régime de financement IRG - Marie Curie actions-International re-integration grants Coordinateur ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE Contribution de l’UE Aucune donnée Adresse LAUSANNE Suisse Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée
