Effect of Supercollisions on Energy Transfer in Mixtures of Bath Gases and Laser Excited Complex Molecules

Intensities and decay rates of delayed luminescence (DL) initiated by a pulse of N₂ laser were employed to probe collisional relaxation of complex molecules (benzophenone, acetophenone) diluted with bath gases Ar, Kr, Xe, C₂H₄, SF₆, C₅H₁₂. It was shown that vibrational relaxation can be interpreted in terms of two consecutive processes: vibration-vibration (V-V) and vibration-translation (V-T). The results clearly demonstrated that fast component of DL can be used to study V-V energy transfer. It was found that at relatively small internal energy the collisional efficiences of V-V process had the values typical for molecular processes in which supercollisions contribute. The average energies transferred per collision, (ΔE), well correlated with predictions of the simple ergodic collision theory of intermolecular energy transfer.