Dynamics of Br(²P_j) formation in the photodissociation of bromobenzene

The photodissociation dynamics of bromobenzene near 234 nm has been investigated using a two-dimensional photofragment ion-imaging technique coupled with a state-selective [2+1] resonance-enhanced multiphoton ionization (REMPI) scheme. The nascent Br atoms are produced by the primary C-Br bond dissociation, which leads to the formation of C₆H₅ (X̃) and Br(₂P_j, j = 1/2, 3/2). The observed translational energy distributions have been fitted by a single Boltzmann function and two Gaussian functions. Trimodal translational energy distributions of Br(²P _j) have been assigned to the direct/indirect dissociation mechanisms originating from the initially excited³(π,π^*) state. The assignments have been confirmed by the recoil anisotropy and distribution width corresponding to the individual components.