Energetics and dynamics in the dissociative photoionization of PF3 at 21.2 eV

The first five electronically excited states of PF+3 generated by He i photoionization are found to dissociate exclusively to PF+2 with dynamically distinct mechanisms. A pronounced correlation is observed between the direction of ejection of the photoelectron and the photofragment ion which issue from individual photoionization events, from which it is inferred that both the photoelectron emission and the subsequent unimolecular ion dissociation are highly anisotropic processes. Measurement of the kinetic energy which accompanies PF+2 formation at its experimental onset is used to identify the preferred thermochemical threshold value for this ion.