FY 2010 Laboratory studies of products of N2O5 uptake on Cl– containing substrates Roberts, J.M., H.D. Osthoff, S.S. Brown, A.R. Ravishankara, D. Coffman, P.K. Quinn, and T.S. Bates Geophys. Res. Lett., 36, L20808, doi: 10.1029/2009GL040448 (2009) The reaction of dinitrogen pentoxide with chloride-containing substrates over a concentration range relevant to the atmosphere was examined using cavity ring-down spectroscopy (CaRDS) and chemical ionization mass spectrometry (CIMS). The main product, nitryl chloride (ClNO2), was formed in efficiencies in the range 0.2 to 0.8 for chloride concentrations of 0.02 to 0.5M. These values are somewhat lower than those from previous, less detailed, measurements carried out mainly at much larger chloride concentrations in NaCl-water mixtures. Substrates having pH<2 also evolved molecular chlorine (Cl2), with ClNO2 as an intermediate. The ClNO2 yields are compared to recent field measurements of N2O5 and ClNO2 as a function of aerosol chloride concentration and shown to quantitatively explain the observations. Feature Publications | Outstanding Scientific Publications Contact Sandra Bigley | Help