REACTIVE SCATTERING OF ATOMS AND RADICALS

Dynamical studies of elementary gas-phase bimolecular reactions have p rogressed significantly during the last few years owing to advancement s in molecular beam and laser techniques as well as in theoretical met hodologies. In this article we give a brief overview of the recent pro gress in the field of reaction dynamics and then survey recent work fr om our laboratory on reactions of atoms and radicals with simple molec ules by the crossed molecular beam scattering method using mass-spectr ometric detection. Emphasis is on three-atom (A + BC) and four-atom (A B + CD) reactions for which the interplay between experiment and theor y is the strongest and the most detailed. Reactive differential cross- sections for the three-atom Cl + H-2 and four-atom OH + H-2 and OH + C O reactions are presented and compared with the results of quasiclassi cal and quantum-mechanical scattering calculations on ab initio potent ial-energy surfaces in an effort to assess the status of theory versus experiment. The reaction dynamics of electronically excited atoms are discussed too; the effect of electronic excitation on the reaction dy namics of atomic oxygen is examined using the reaction O(P-3,D-1) + H2 S as an example.