This paper reviews the time-resolved infrared fluorescence technique and its application to studies of the deactivation of highly vibrationally excited benzene-d0, benzene-d6, toluene-d0, and toluene-d8. The energy transfer parameters obtained are summarized in terms of both «ΔE» and <ΔE>d, the average total energy transferred per collision and the average energy transferred in deactivating collisions, respectively. The mechanisms of energy transfer have also been investigated to determine the roles of vibration-to-translation/rotation and vibration-to-vibration energy transfer and the possible influence of quantum effects. The review concludes with a brief summary of a current view of large molecule energy transfer and suggestions for future work.