Photochemistry of hydrated electron clusters (H2O)−<i>n</i> (15≤<i>n</i>≤40) at 1064 nm: Size dependent competition between photofragmentation and photodetachment

Abstract

Photofragmentation is found to be surprisingly efficient when hydrated electron clusters (H2O)−n, 15≤n≤40, are excited at 1064 nm (1.165 eV). The decay probability into ionic channels rises sharply from zero in the size range 15≤n≤20 before leveling off at a value of 0.56±0.10. The propensity of smaller clusters to detach an electron rather than fragment is correlated with the peculiar shape of the cluster ion distribution obtained by dissociative attachment of low energy electrons onto neutral water clusters, where the ionic clusters are only observed in abundance for n≥11.