- The Synthesis of 15N- and 18O-Isotopically-Enriched Nitryl Bromide, IR Matrix Spectra, and Force Fields of BrNO2, cis-BrONO, and trans-BrONO
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The gas phase reaction between BrNO and O3 at low pressure (2 in about 60% yield. In this manner 15N- and 18O-labeled BrNO2 are prepared. In addition, it is shown that BrNO2 also forms by the heterogeneous low-temperature reaction between gaseous BrNO and solid sulfuric acid, doped with H2O2. It can be assumed that BrNO2 may be formed in a similar way under stratospheric conditions. The isotope scrambling in the reaction between BrNO and 18O3 as well as in the gas phase equilibrium BrNO + NO2 ? BrNO2 + NO are investigated. For the equilibrium constant a lower limit of K298 ≥ 1 × 10-3 is deduced from infrared measurements. A detailed IR and Raman study on BrNO2 is performed. Photolysis of matrix-isolated BrNO2 at different wavelengths leads to a mixture of cis- and trans-BrONO. The vibrational data of BrNO2 (6 fundamentals, 7 combinations), cis-BrONO (5 fundamentals, 1 overtone), and trans-BrONO (4 fundamentals, 8 combinations) as well as the calculated force fields are in excellent agreement with the ab initio values, predicted by T. J. Lee (J. Phys. Chem. 1996, 100, 19847).
- Scheffler, Dieter,Willner, Helge
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p. 4500 - 4506
(2008/10/08)
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- Reactivity of BrNO2 and ClNO2 with solid alkali salt substrates
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The reactions of BrNO2 and ClNO2 with bromide have been studied in a Knudsen-cell reactor in order to better understand the elementary reactions of these potentially important tropospheric species in the presence of solid sea-salt aerosol. BrNO2 efficiently reacts with bromide to produce molecular bromine (γ > 0.3). To better understand the fate of BrNO2 in the Knudsen-cell reactor, we have developed a BrNO2 source based on the reaction of molecular bromine with solid KNO2. We have determined that the lifetime of BrNO2 under our experimental conditions is on the order of 10 s and is limited by heterogeneous decomposition reactions. The interaction of BrNO2 with KBr, KCl, and KNO2 was studied using the external BrNO2 source. ClNO2 can be converted to BrNO2 in the presence of solid bromide, characterized by an uptake probability of γ = 1.3 × 10-4, in good agreement with results obtained for several substrate presentations such as salt powder, grain, and single crystals. We compared these results with previous work and briefly discuss atmospheric implications.
- Caloz, Franc?ois,Seisel, Sabine,Fenter, Frederick F.,Rossi, Michel J.
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p. 7470 - 7479
(2007/10/03)
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- Synthesis and Identification by Infrared Spectroscopy of Gaseous Nitryl Bromide
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The reactions at 298 K of gaseous N2O5 with NaBr(s) or with BrNO(g) in 1 atm of helium were followed by using Fourier transform infrared spectroscopy.In both cases, the formation of infrared absorption bands at 787, 1292, and approximately 1660 cm-1
- Finlayson-Pitts, Barbara J.,Livingston, Frank E.,Berko, Henry N.
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p. 4397 - 4400
(2007/10/02)
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