Jump in depletion rates of highly excited O2: reaction or enhanced vibrational relaxation?

A simple model is used to calculate vibrational self-relaxation rates of highly excited oxygen. In contrast to previous theoretical treatments, the model reproduces the experimental observation of a sharp increase in depletion rates above a critical value of v. It is proposed that the observed jump in O‡2(v) depletion rates is partially due to inelastic collisions, rather than to ozone formation. It is also shown that the presence of the reactive transition state region in the potential energy surface is the key for the enhancement of the relaxation rates.