The kinetics of NaO + O 2 + M and NaO + CO 2 + M and their role in atmospheric sodium chemistry

We have discovered a new type of reaction for atmospheric Na species and propose that this type of reaction will dominate its chemistry. The third order rate constants for NaO + O 2 + M and NaO + CO 2 + M were measured at 297 K in a flow tube study. The rate constants for NaO + O 2 with He, N 2 , and N 2 O as third bodies are (1.3±0.8), (3.5±0.7), and (11±4)×10 −30 cm 6 molecule −2 s −1 . The rate constants for NaO + CO 2 with N 2 and N 2 O as third bodies are (8.7±2.6) and (12±5)×10 −28 cm 6 molecule −2 s −1 . We show that these association reactions, and others like them, will produce Na compounds that are likely to render Na species inactive in stratospheric ozone chemistry. The reactivities of NaO, NaO 2 , NaO 3 , and NaCO 3 with O atoms were also tested.