Kinetic energy release measurements have been performed following the metastable and infrared photoinduced decay of SF 6 . (C 6 H 6 ) n + cluster ions. Using a model due to Klots [J. Chem. Phys. 58 (1973) 5364], photofragment kinetic energy releases have been predicted on the assumption that energy from the photon (~950 cm - 1 deposited into the ν 3 of the SF 6 moiety) is partitioned statistically throughout the cluster ion. However, a comparison between experimental and calculated results suggests that incomplete energy randomisation may be taking place, and a better description of the photofragmentation process is provided on the assumption that the excited vibrational mode undergoes partial relaxation to either the ν 2 or ν 4 modes. The energy difference (~300 cm - 1 ) is then randomised and is reflected in the magnitudes of the measured kinetic energy releases.