Subject saddle region

The dynamics near the TS have been the subject of many theoretical [52-66] and experimental [24,25] investigations. The experiments of Lovejoy and co-workers [24,25] see the TS via the photofragment excitation spectra for unimolecular dissociation of excited ketene. They have shown that, in the vicinity of the barrier, the reaction rate is controlled by the flux through quantized thresholds. The observability of quantized thresholds in the TS was first discussed by Chatfield et al. [23]. Marcus pointed out that this indicates that the transverse vibrational quantum numbers might indeed be approximate constants of the motion in the saddle region [60]. 

---