Final Report Summary - CAPRI (Chemical and photochemical dynamics of reactions in solution) Many chemical processes of importance to industry, the environment or living organisms occur in solution in a liquid. Visualizing the motions of the reacting molecules during these chemical processes, and the steps by which the molecules convert from reactants to products, is challenging because they and the surrounding molecules of the solvent are in constant motion. Collisions between the solute and solvent molecules occur at intervals of less than a trillionth of a second, and these interactions blur out measurements of the molecular motions. Using laser pulses shorter in time than the intervals between collisions, this project has been able to observe chemical reactions in liquids in unprecedented detail. Some reactions liberate energy, and the way in which this energy flows from the reacting molecules into the surrounding liquid has also been observed. The very early steps in chemical reactions have been recorded, and new chemical pathways have been identified through which molecules lose excess energy and avoid damage, for example when exposed to ultraviolet radiation.
