V-V energy transfer from highly vibrationally excited molecules through transition dipole coupling: A quantitative test on energy transfer from SO2 (v >> 0) to SF6(3(1))

Time-resolved Fourier transform IR emission spectroscopy has been used to m onitor the population distribution of both the energy giving molecules and the energy receiving molecules during collisional quenching of highly vibra tionally excited SO2 by bath-gas SF6. The change in population of the SF6 n u (3) = 1 level measured as a function of rime is compared with that calcul ated based on the transition dipole coupling model with the transition dipo le of highly excited SO2 extracted from its IR emission spectra. The excell ent agreement indicates that long-range interaction through transition dipo le coupling is responsible for the vibration to vibration energy transfer f rom the highly excited molecules.