Kinetic studies of reactions of the nitrate radical (NO3) with peroxy radicals (RO2): an indirect source of OH at night?

Research output: Contribution to journalArticle


  • S. Vaughan
  • C.E. Canosa-Mas
  • D.E. Shallcross
  • L. Watson
  • R.P. Wayne

Colleges, School and Institutes


A discharge–flow system, coupled to cavity-enhanced absorption spectroscopy (CEAS) detection systems for NO3 at λ = 662 nm and NO2 at λ = 404 nm, was used to investigate the kinetics of the reactions of NO3 with eight peroxy radicals at P ∼ 5 Torr and T ∼ 295 K. Values of the rate constants obtained were (k/10−12 cm3 molecule−1 s−1): CH3O2 (1.1 ± 0.5), C2H5O2 (2.3 ± 0.7), CH2FO2 (1.4 ± 0.9), CH2ClO2 (3.8+1.4−2.6), c-C5H9O2 (1.2+1.1−0.5), c-C6H11O2 (1.9 ± 0.7), CF3O2 (0.62 ± 0.17) and CF3CFO2CF3 (0.24 ± 0.13). We explore possible relationships between k and the orbital energies of the reactants. We also provide a brief discussion of the potential impact of the reactions of NO3 with RO2 on the chemistry of the night-time atmosphere.


Original languageEnglish
Pages (from-to)3749-3760
Number of pages12
JournalPhysical Chemistry Chemical Physics
Issue number32
Publication statusPublished - 12 Jul 2006