Photodissociation dynamics of fluorobenzene

Photodissociation of both fluorobenzene and d(5)-fluorobenzene at 193 nm under collision-free conditions has been studied in separate experiments using multimass ion imaging techniques. HF and DF eliminations were found to be the major dissociation channels. Small amounts of photofragments, C(6)H(4)F and C(6)D(4)F, corresponding to H and D atom eliminations were also observed. Dissociation rate and fragment translational energy distribution suggest that HF (DF) and H (D) atom elimination reactions occur in the ground electronic state. The potential energy surface obtained from ab initio calculations indicates that the four-center reaction in the ground electronic state is the major dissociation mechanism for the HF and DF eliminations. A comparison with photodissociation of benzene has been made.