The technique of velocity map imaging has been used to determine the dissociation energy for the process p-difluorobenzene-Ar-2 --> 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-Ar-2 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 similar to2% or less. (C) 2002 Elsevier Science B.V. All rights reserved.