IR-induced population transfer

To date, only IR photon energies in the H-stretching range have been used in IR-induced population transfer experiments, which for most systems results in excitation far above the isomerization barrier, impeding an experimental determination of the isomerization barriers directly. Zwier and coworkers presented an elegant alternative, where stimulated emission pumping (SEP) is combined with HF or PTS methods, see Fig. 2d. This combination allows one to probe the barrier to conformational isomerization [56]. The method consists of two steps a pump-dump SEP followed by a probe laser interrogation to determine the new cmifomiational distribution. In the early part of the molecular beam expansimi, SEP prepares the... 

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