Oxygenated volatile organic compounds

At his point, it seems worthwhile to revisit the peculiar intramolecular bond that appears in the most abundant isomer of glycolaldehyde, which shows an OO-s-cis configuration, since it is relevant to SAR predictions. The glycolaldehyde -I-OH rate constant that predicted by SAR is 2.3 x 10 cm /(molecules), while the average obtained from the available experimental data is 9.25 x 10 cm / (molecules). The reaction profiles of the acetaldehyde, ethanol and glycolaldehyde -I- OH reactions have been modeled at the same level of theory. 

FIGURE 12.10 Two typical rearrangements reported for hydroxyacetona + OH reactant complexes. 

TABLE 12.7 Overall rate coefficients (cm /(molecule s)) at room temperature for different MO-VOC + OH reactions 

CCSD(T)/6-311++G(d,p)//BHandHLYP/6-311++G(d,p) [169]. The authors found that he ZPE corrected barriers for H abstractions from the alpha position in ethanol and from the aldehydic site in acetaldehyde are 0.2 kcal/mol lower than those corresponding to the equivalent abstractions in glycolaldehyde. This difference is responsible for the decrease in k. In SAR, the deactivation of the -CH2 site by the G=0 substituent is taken into account by introducing a factor F( C=0) = 0.75. However, no deactivation is considered for the aldehydic abstraction. This deactivation occurs because of the intramolecular hydrogen bond in OO-s-cis glycolaldehyde, which is a very specific characteristic of this molecule. 

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Picquet, B., S. Heroux, A. Chebbi, J.-F. Doussin, R. Durand-Jolibois, A. Monod, H. Loirat, and P. Carlier, Kinetics of the Reactions of OH Radicals with Some Oxygenated Volatile Organic Compounds under Simulated Atmospheric Conditions, Int. J. Chem. Kinel., 30, 839-847 (1998). 

K. Olszyna, T. Kleindienst, W. Lonneman, S. Bertman, P. Shep-son, and T. Starn, Observations of Nonmethane Hydrocarbons and Oxygenated Volatile Organic Compounds at a Rural Site in the Southeastern United States, J. Geophys. Res., 103, 28111-28128 (1998). 

Atmospheric Reactions of Oxygenated Volatile Organic Compounds + OH Radicals ... 

Jenkin ME, Hayman GD (1999) Photochemical ozone creation potentials for oxygenated volatile organic compounds sensitivity to variations in kinetic and mechanistic parameters. 

Many of the volatiles from plants are oxygenated volatile organic compounds (OVOCs). Measurement of OVOCs is difficult (e.g., methanol easily partitions with water) and, in many cases, time-consuming (up to 1 h per sample). This is too slow to measure fast emissions/ changes (e.g., when a plant is wounded), and in this case, PTR-MS can be useful. PTR-MS can measure a wide range of compounds (including OVOCs and sulfur compounds among others) fast and on-line, which makes it a suitable method to study on-line plant emissions and uptake. 

Kesselmeier J (2001) Exchange of short-chain oxygenated volatile organic compounds (VOCs) between plants and the atmosphere a compilation of field and laboratory studies. J Atmos Chem 39 219... 

Removal of oxygenated volatile organic compounds by catalytic oxidation over Zr-Ce-Mn catalysts. /. Hazard. Mater., 188 (1-3), 422-427. 

The oxidation reactions of alkanes, alkenes and aromatic hydrocarbons treated in this section are described in detail in monographs by Calvert et al. (2000, 2002, 2008), and reaction mechanisms for air quality models are summarized by StockweU et al. (2012). Also, Calvert et al. (2011) and Mellouki et al. (2003) reviewed the oxidation reactions of oxygenated volatile organic compounds (OVOCs) which are not treated in this book. Detailed models for the photolysis... 

Wyche, K. P., Blake, R. S., Ellis, A. M. et al. (2007) Technical Note Performance of Chemical Ionization Reaction Time-of-Flight Mass Spectrometry (CIR-TOF-MS) for the measurement of atmospherically significant oxygenated volatile organic compounds. Atmos. Chem. Phys. 7, 609. 

Miyakawa, Y., Kato, S., Kajii, Y. (2005) Calibration of the proton transfer reaction mass spectrometry (PTR-MS) instrument for oxygenated volatile organic compounds (OVOCs) and the measurement of ambient air in Tokyo. Taiki Kankyo Gakkaishi (Journal of Japan Society for Atmospheric Environment) 40,209. 

Graus, M., Schnitzler, J. P., Hansel, A. et al. (2004) Transient release of oxygenated volatile organic compounds during light-dark transitions in grey poplar leaves. Plant... 

Heiden, A. C., Kobel, K., Langebartels, C. et al. (2003) Emissions of oxygenated volatile organic compounds from plants part i emissions from lipoxygenase activity. 

S. Reimann (2007), Oxygenated volatile organic compounds (OVOCs) at an urban background site in Zurich (Europe) Seasonal variation and source allocation, Atmo . Envimn., 41, 8409-8423. 

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