Dynamics of solvation-induced structural transitions in mesoscopic binary clusters

Ion solvation dynamics following collision of K+ with mesoscopic water-ammonia aggregates is investigated. Two processes determine the postcollision state of the clusters: First, a morphological transformation from a structure characterized by a solid water core and a liquid-phase ammonia sheath into a dumbbell-shaped cluster composed of a liquid water droplet attached to an ammonia subcluster containing the solvated ion. Second, evaporation cools the cluster during and after the morphological change and this evaporative cooling is quantitatively characterized by determining the size-dependent rate constants for these complex clusters.