Photodissociation of o-bromotoluene at 266 nm

The photodissociation of o-bromotoluene at 266 nm has been investigated usi ng the universal crossed laser-molecular beam technique. The angle-resolved time-of-flight (TOF) spectra corresponding to Br photofragment are measure d at different lab angles. The observed translational energy distribution a nd anisotropy parameters of the Br photofragment indicate that o-bromotolue ne dissociates via two channels. In the first channel, the anisotropy param eter beta is determined to be 0.5 +/- 0.2 and the average translational ene rgy is only 9% of the available energy. In the other photofragmentation cha nnel, beta is determined to be - 0.4 +/- 0.2 and 44% of the available energ y is assigned to translational energy. Possible mechanisms are discussed. ( C) 1999 Elsevier Science B.V. All rights reserved.