INFRARED MULTIPHOTON EXCITATION DYNAMICS OF CF3I .2. COLLISIONAL EFFECTS ON VIBRATIONAL AND ROTATIONAL STATE POPULATIONS

Time-resolved resonantly enhanced multiphoton ionization spectroscopy of I(2P3/2) and I(2P1/2) dissociation products of CF3I can be used to characterize populations of highly-excited CF3I*. This technique has been applied to monitor infrared multiphoton excitation dynamics of CF3I in the presence of collisions. Compared to collision-free situations, collisions tend to destroy bimodal vibrational energy distributions and to enhance the overall pumping rate. Collisional energy transfer could be monitored for molecules above the dissociation threshold. Collisional relaxation of highly-excited molecules has been followed and analyzed with respect to average energies transferred per collision.