Photoionization and photofragmentation of SF in helium nanodroplets

The photoionization of He droplets doped with SF was investigated using tunable vacuum ultraviolet (VUV) synchrotron radiation from the Advanced Light Source (ALS). The resulting ionization and photofragmentation dynamics were characterized using time-of-flight mass spectrometry combined with photofragment and photoelectron imaging. Results are compared to those of gas-phase SF molecules. We find dissociative photoionization to SF to be the dominant channel, in agreement with previous results. Key new findings are that (a) the photoelectron spectrum of the SF in the droplet is similar but not identical to that of the gas-phase species, (b) the SF photofragment velocity distribution is considerably slower upon droplet photoionization, and (c) fragmentation to SF and SF is much less than in the photoionization of bare SF. From these measurements we obtain new insights into the mechanism of SF photoionization within the droplet and the cooling of the hot photofragment ions produced by dissociative photoionization. © 2006 American Chemical Society.