Isoprene nitrates: preparation, separation, identification, yields, and atmospheric chemistry
Open Access
- 8 July 2010
- journal article
- research article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 10 (13) , 6169-6178
Abstract
Isoprene is an important atmospheric volatile organic compound involved in ozone production and NOx (NO+NO2) sequestration and transport. Isoprene reaction with OH in the presence of NO can form either isoprene hydroxy nitrates ("isoprene nitrates") or convert NO to NO2 which can photolyze to form ozone. While it has been shown that isoprene nitrate production can represent an important sink for NOx in forest impacted environments, there is little experimental knowledge of the relative importance of the individual isoprene nitrate isomers, each of which has a different fate and reactivity. In this work, we have identified the 8 individual isomers and determined their total and individual production yields. The overall yield of isoprene nitrates at atmospheric pressure and 295 K was found to be 0.070(+0.025/−0.015). Three isomers, representing nitrates resulting from OH addition to a terminal carbon, represent 90% of the total IN yield. We also determined the ozone rate constants for three of the isomers, and have calculated their atmospheric lifetimes, which range from ~1–2 h, making their oxidation products likely more important as atmospheric organic nitrates and sinks for nitrogen.Keywords
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This publication has 36 references indexed in Scilit:
- Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic speciesAtmospheric Chemistry and Physics, 2006
- A study of the NOx dependence of isoprene oxidationJournal of Geophysical Research: Atmospheres, 2004
- Alkyl Nitrate, Hydroxyalkyl Nitrate, and Hydroxycarbonyl Formation from the NOx−Air Photooxidations of C5−C8 n-AlkanesThe Journal of Physical Chemistry A, 2001
- A study of relationships between isoprene, its oxidation products, and ozone, in the Lower Fraser Valley, BCAtmospheric Environment, 1997
- Hydroxyl radical production from the gas-phase reactions of ozone with a series of alkenes under atmospheric conditionsEnvironmental Science & Technology, 1993
- Density-functional thermochemistry. III. The role of exact exchangeThe Journal of Chemical Physics, 1993
- Photoenhancement of the nitrous acid formation in the surface reaction of nitrogen dioxide and water vapor: Extra radical source in smog chamber experimentsInternational Journal of Chemical Kinetics, 1987
- Kinetics and mechanisms of the gas-phase reactions of the hydroxyl radical with organic compounds under atmospheric conditionsChemical Reviews, 1986
- Alkyl nitrate formation from the nitrogen oxide (NOx)-air photooxidations of C2-C8 n-alkanesThe Journal of Physical Chemistry, 1982
- Kinetics of the gas‐phase reactions of OH radicals with alkyl nitrates at 299 ± 2 KInternational Journal of Chemical Kinetics, 1982