Dynamics of Inelastic and Reactive Collisions of 16 O( 3 P) with 15 N 18 O.

The dynamics of O( 3 P) + NO collisions were investigated at a collision energy of ⟨ E coll ⟩ = 84.0 kcal mol -1 with the use of a crossed molecular beams apparatus employing a rotatable mass spectrometer detector. This experiment was performed with beams of 16 O atoms and isotopically labeled 15 N 18 O molecules to enable the products of reactive and inelastic scattering to be distinguished. Three scattering pathways were observed: inelastic scattering ( 16 O + 15 N 18 O), O-atom exchange ( 18 O + 15 N 16 O), and O-atom abstraction ( 18 O 16 O + 15 N). All product channels exhibited a preponderance of forward scattering, but scattering over a broad angular range was also observed for all products. For inelastic scattering, an average of 90% of the collision energy is retained in the translation of 16 O and 15 N 18 O. On the other hand, for O-atom exchange (which also leads to O + NO products), the collision energy is partitioned roughly evenly between the translation of 18 O + 15 N 16 O and the internal excitation of 15 N 16 O. The available energy for O-atom abstraction is significantly lower than the collision energy because of the endoergicity of this reaction, but the available energy is again roughly evenly partitioned between the translation of 18 O 16 O + 15 N and the internal excitation of the molecular (O 2 ) product. The relative yields of the three scattering pathways were determined to be 0.751 for inelastic scattering, 0.220 for O-atom exchange, and 0.029 for O-atom abstraction.