The dynamics of the light atom transfer reaction O(P-3(J))+HBr -> OH(v ', j ')+Br(P-2(J '))

The dynamics of the title light-atom transfer reaction have been investigat ed using laser pump and probe techniques at a mean collision energy close t o 0.3 eV. The experiments employed 308 nm photodissociation of NO2 to gener ate translationally excited O(P-3) atoms, and were conducted at room temper ature. OH quantum state populations were found to be in excellent accord wi th those determined by McKendrick et al. [Faraday Discuss. Chem. Soc., 1987 , 84, 39]. OH Doppler resolved laser induced fluorescence was used to deter mine the angular distribution of the scattered OH products. For OH((2)Pi (3 /2), A') born in (v' = 1, N' = 5) the angular distribution was found to be broad, but peaked towards the forward direction, consistent with expectatio n based on kinematic considerations. More interestingly, a consistent fit t o the experimental data could only be achieved by assuming that 10% of the OH(v' = 1, N' = 5) products are partnered by spin-orbit excited state Br(P- 2(1/2)) atoms. The data suggest that at comparable energies above their res pective energetic thresholds, the reaction cross-sections for production of OH((2)Pi (3/2), A', v' = 1, N' = 5) in conjunction with Br and Br* are sim ilar.