Abstract
Rate constants for the reaction of OH radicals with some branched alkyl nitrates have been measured applying a competitive technique. Methyl nitrite photolysis in synthetic air was used as OH radical source at 295±2 K and 1000 mbar total pressure. Using a rate constant of 2.53×10-12 cm3 s-1 for the reaction of OH radicals with n-butane as reference, the following rate constants were obtained (units: 10-12 cm3 s-1): isopropyl nitrate, 0.59±0.22; isobutyl nitrate, 1.63±0.20; 3-methyl-2-butyl nitrate, 1.95±0.15; 2-methyl-1-butyl nitrate, 2.50±0.15; 3-methyl-1-butyl nitrate, 2.55±0.35. These values have been combined with the literature data to recalculate the substituent factors F(X) for the different nitrate groups which can be used to predict OH rate constants for organic nitrates for which experimental data are not available.
Preliminary measurements of the photolysis frequency of isopropyl nitrate have shown that for this nitrate as a model substance, OH reactions and direct photolysis are of equal importance under tropospheric conditions.
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Atkinson, R., Aschmann, S. M., Carter, W. P. L., Winer, A. M., and Pitts, J. N.Jr., 1982a, Alkyl nitrate formation from the NO x -air photooxidations of C2−C8 alkanes, J. Chem. Phys. 86, 4563–4569.
Atkinson, R., Aschmann, S. M., Carter, W. P. L., and Winer, A. M., 1982b, Kinetics of the gasphase reactions of OH radicals with alkyl nitrates at 299±2 K, Int. J. Chem. Kinet. 14, 919–926.
Atkinson, R., Aschmann, S. M., Carter, W. P. L., Winer, A. M., and Pitts, J. N.Jr., 1982c, Kinetics of the reaction of OH radicals with n-alkanes at 299±2 K, Int. J. Chem. Kinet. 14, 781–788.
Atkinson, R., Carter, W. P. L., and Winer, A. M., 1983, Effects of temperature and pressure of alkyl nitrate yields in the photooxidations of n-pentane and n-heptane, J. Phys. Chem. 87, 2012–2018.
Atkinson, R. and Lloyd, A. C., 1984, Evaluation of kinetic and mechanistic data for modelling of photochemical smog, J. Phys. Chem. Ref. Data 13, 315–444.
Atkinson, R., Aschmann, A. M., Carter, W. P. L., Winer, A. M., and Pitts, J. N.Jr., 1984, Formation of alkyl nitrates from the reaction of branched and cyclic peroxy radicals with NO, Int. J. Chem. Kinet. 16, 1085–1101.
Atkinson, R., 1986, Kinetics and mechanisms of the gas-phase reactions of the OH radical with organic compounds under atmospheric conditions, Chem. Rev. 86, 69–201.
Atkinson, R., Winer, A. M., and Pitts, J. N.Jr., 1986, Estimations of night-time N2O5 concentrations from ambient NO2 and NO3 radical concentrations and the role of N2O5 in night-time chemistry, Atmos. Environ. 20, 331–339.
Atkinson, R., 1987, A structure-activity relationship for the estimation of rate constants for the gas-phase reactions of OH radicals with organic compounds, Int. J. Chem. Kinet. 19, 799–828.
Atkinson, R., Aschmann, S. M., and Winer, A. M., 1987, Alkyl nitrate formation from the reaction of branched RO2 radicals with NO as a function of temperature and pressure, J. Atmos. Chem. 5, 91–102.
Atlas, E., 1988, Evidence for ≥C3 alkyl nitrates in rural and remote atmospheres, Nature 331, 426–428.
Becker, K. H., Biehl, H. M., Bruckmann, P., Fink, E. H., Führ, F., Klöpffer, W., Zellner, R., and Zetzsch, C., 1984, Methods of the ecotoxicological evaluation of chemicals, Photochemical degradation in the gas phase, Spezielle Berichte der Kernforschungsanlage Jülich No. 279.
Barnes, I., Becker, K. H., Fink, E. H., Reimer, A., Zabel, F., and Niki, H., 1983, Rate constant and products of the reaction of CS2+OH in the presence of O2, Int. J. Chem. Kinet. 15, 631–645.
Calvert, J. G. and Pitts, J. N.Jr., 1966, Photochemistry, Wiley, New York, p. 454.
Calvert, J. G. and Madronich, S., 1987, Theoretical study of the initial products of the atmospheric oxidation of hydrocarbons, J. Geophys. Res. 92, 2221–2222.
Carter, W. P. L. and Atkinson, R., 1985, Atmospheric chemistry of alkanes, J. Atmos. Chem. 3, 377–405.
Chatfield, R. B., Gardner, E. P., and Calvert, J. G., 1987, Sources and sinks of acetone in the troposphere: behavior of reactive hydrocarbons and a stable product, J. Geophys. Res. 92, 4208–4216.
Csizmadia, V. M., Houlden, S. A., Koves, G. J., Boggs, J. M., and Csizmadia, I. G., 1973, The stereochemistry and ultraviolet spectra of simple nitrate esters, J. Org. Chem. 38, 2281–2287.
Darnall, K. R., Carter, W. P. L., Winer, A. M., Lloyd, A. C., and Pitts, J. N.Jr., 1976, Importance of RO2+NO in alkyl nitrate formation from C4−C6 alkane photooxidation under simulated atmospheric conditions, J. Phys. Chem. 80, 1948–1950.
Demerjian, K. L., Schere, K. L. and Peterson, J. T., 1980, Theoretical estimates of actinic (spherically integrated) flux and photolytic rate constants of atmospheric species in the lower troposphere, Adv. Environ. Sci. Technol. 10, 369.
Finlayson-Pitts, B. J. and Pitts, J. N.Jr., 1986, Atmospheric chemistry: Fundamentals and experimental techniques, Wiley, New York, p. 110.
Gaffney, J. S. and Levine, S. Z., 1979, Predicting gas-phase organic molecule reaction rates using linear free energy correlations I. O(3P) and OH addition and abstraction reactions, Int. J. Chem. Kinet. 11, 1197–1209.
Gaffney, J. S., Fajer, R., Senum, G. I., and Lee, J. H., 1986, Measurement of the reactivity of OH with methyl nitrate: implications for prediction of alkyl-nitrate-OH reaction rates, Int. J. Chem. Kinet. 18, 399–407.
Gardner, E. P., Wijayaratne, R. D., and Calvert, J. G., 1984, Primary quantum yields of photodecomposition of acetone in air under tropospheric conditions, J. Phys. Chem. 88, 5069–5076.
Gray, J. A. and Style, D. W. G., 1953, The photolysis of ethyl nitrate, Trans. Faraday Soc. 49, 52–57.
Jet Propulsion Laboratory (JPL), 1987, Chemical kinetics and photochemical data for use in stratospheric modeling, evaluation number 8, JPL Publ., 87-41, 1–196.
Kerr, J. A. and Stocker, D. W., 1986, Kinetics of the reaction of hydroxyl radicals with alkyl nitrates and some oxygen containing organic compounds studied under simulated atmospheric conditions, J. Atmos. Chem. 4, 253–262.
Kornblum, N. and Teitelbaum, C., 1952, The basis for the report that rearrangements occur when cyclopentyl iodide and cyclohexyl iodide react with silver nitrate, J. Am. Chem. Soc. 74, 3076–3078.
Lee, Y. N., Senum, G. I., and Gaffney, J. S., 1983, Peroxyacetyl nitrate (PAN) stability, solubility, and reactivity implications for tropospheric nitrogen cycles and precipitation chemistry, Fifth Int. Conf. of the Comm. on Atmos. Chem. and Global Poll., Symposium on Tropospheric Chemistry, Oxford, England, August/September 1983, p. 38.
Logan, J. L., Prather, M. J., Wofsy, S. C., and McElroy, M. B., 1981, Tropospheric chemistry: A global perspective, J. Geophys. Res. 86, 7210–7254.
Luke, W. T. and Dickerson, R. R., 1988, Direct measurements of the photolysis rate coefficient of ethyl nitrate, Geophys. Res. Lett. 15, 1181–1184.
Peterson, J. T., 1976, Calculated actinic fluxes (290–700 nm) for air pollution photochemistry applications, U.S. Environmental Protection Agency Report No. EPA-600/4-76-025.
Perner, D., Platt, U., Trainer, M., Hübler, G., Drummond, J., Junkermann, W., Rudolph, J., Schubert, B., Volz, A., and Ehhalt, D. H., 1987, Measurements of tropospheric OH concentrations: a comparison of field data with model predictions, J. Atmos. Chem. 5, 185–216.
Platt, U. F., Perner, D., Schröder, J., Kessler, C., and Toennissen, A., 1981, The diurnal variation of NO3, J. Geophys. Res. 86, 11,965–11,970.
Platt, U. F., Winer, A. M., Biermann, H. W., Atkinson, R., and Pitts, J. N.Jr., 1984, Measurement of nitrate radical concentrations in continental air, Environ. Sci. Technol. 18, 365–369.
Salter, L. F. and Thrush, A., 1977, Reaction of oxygen atoms with methyl and ethyl nitrate, J. Chem. Soc. Faraday Trans. 1, 73, 1098–1103.
Taylor, W. D., Allston, T. D., Moscato, M. J., Fazekus, G. B., Kozlowski, R., and Takacs, G. A., 1980, Atmospheric photodissociation lifetimes for nitro methane, methyl nitrite and methyl nitrate, Int. J. Chem. Kinet. 12, 231–240.
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Becker, K.H., Wirtz, K. Gas phase reactions of alkyl nitrates with hydroxyl radicals under tropospheric conditions in comparison with photolysis. J Atmos Chem 9, 419–433 (1989). https://doi.org/10.1007/BF00114754
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DOI: https://doi.org/10.1007/BF00114754