PHOTODISSOCIATION OF CFCL3 AT 193 NM INVESTIGATED BY PHOTOFRAGMENT TRANSLATIONAL SPECTROSCOPY

The collisionless photodissociation of CFCl3 at 193 nm has been studie d with the method of crossed laser and molecular beams. The primary di ssociation is shown to produce exclusively the fragment pairs CFCl2 Cl with a non-thermal translational energy distribution. The average k inetic energy of 32 kcal/mol corresponds to 42% of the available energ y and implies an average internal energy of CFCl2 of 43 kcal/mol. From the recoil anisotropy parameter beta = +0.74 +/- 0.15 the photoexcita tion is inferred to proceed via an E <-- A1 transition polarized perpe ndicular to the C-F bond. At higher laser fluence a fraction of the na scent CFCl2 radicals absorbs a further photon and dissociates into CFC l + Cl; the cross section for this secondary process is estimated to b e approximately twice as large as that of the primary photodissociatio n.