The binding energy of Ar to p-difluorobenzene–Ar. How large are three-body effects in p-difluorobenzene–Ar2?

The technique of velocity map imaging has been used to determine the dissociation energy for the process p-difluorobenzene–Ar2→p-difluorobenzene–Ar+Ar. The aim of the experiment was to obtain a value for comparison with the dissociation energy for the process p-difluorobenzene–Ar→p-difluorobenzene+Ar in order to ascertain the extent of three-body effects. We find that the dissociation energy for the loss of an Ar atom from p-difluorobenzene–Ar2 is 339±3 cm−1, which is the same within experimental uncertainty as that for the loss of Ar from p-difluorobenzene–Ar (337±4 cm−1). We conclude that the presence of the first Ar affects the binding energy of the second by ∼2% or less.