Structure–activity relationship (SAR) for the prediction of gas-phase ozonolysis rate coefficients: an extension towards heteroatomic unsaturated species

McGillen, Max R.; Archibald, Alexander T.; Carey, Trevor J.; Leather, Kimberley E.; Shallcross, Dudley E.; Wenger, John C.; Percival, Carl J.

doi:10.1039/c0cp01732a

Cited by 37 publications

(67 citation statements)

References 32 publications

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“…Room temperature rate constants have been derived for trichloroethene and tetrachloroethene, which have not been determined previously. Although the A-factors presented for trichloroethene and tetrachloroethene are not as expected, the activation energies and extrapolated room temperature rate constants are concordant with predicted trends [51]. Lack of evidence from secondary chemistry interferences through simple model calculations indicate an alternative mechanism is in operation though simple QRRK calculations suggest an enhanced stability of primary ozonides may be responsible for the observed anomaly.…”

Section: Conclusion and Further Worksupporting

confidence: 72%

Temperature‐dependent kinetics for the ozonolysis of selected chlorinated alkenes in the gas phase

Leather

McGillen

Ghalaieny

et al. 2010

Int J of Chemical Kinetics

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The ozonolysis of olefinic species is an important tropospheric process impacting on climate and human health. However, few studies have investigated these reactions as a function of temperature and even less information is available upon the effects of alkene heteroatomic substitution on the Arrhenius parameters. The electron-withdrawing capacity of substituents about the olefinic bond strongly influences the rate of alkene ozonolysis. To understand better the effect of these substitutions, the temperature-dependence of a series of ozonechloroalkene reactions is investigated. Experiments were conducted in the EXTreme RAnge (EXTRA) chamber, over the range of 292-409 K and 760 Torr. The experimentally determined rate coefficients were fitted using an Arrhenius-type analysis to yield the following activation energies: 30.80 ± 0.79, 23.18 ± 0.59, 65.2 ± 2.8, 116.9 ± 5.6, 29.5 ± 1.8, and 18.67 ± 0.96 kJ mol −1 and preexponential A-factors 1.22

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Section: Conclusion and Further Worksupporting

confidence: 72%

Temperature‐dependent kinetics for the ozonolysis of selected chlorinated alkenes in the gas phase

Leather

McGillen

Ghalaieny

et al. 2010

Int J of Chemical Kinetics

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“…many of the rate constants are inferred from other reactions using structure reactivity relationships (SARs, e.g. Kwok and Atkinson, 1995;McGillen et al, 2011), and only four of the six ISO 2 isomers are included. Furthermore, many of the recent discoveries such as the isomerisation chemistry of ISO 2 and methacrolein are not included.…”

Section: Box Model Experimentsmentioning

confidence: 99%

Influence of isoprene chemical mechanism on modelled changes in tropospheric ozone due to climate and land use over the 21st century

et al. 2015

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Abstract. Isoprene is a precursor to tropospheric ozone, a key pollutant and greenhouse gas. Anthropogenic activity over the coming century is likely to cause large changes in atmospheric CO 2 levels, climate and land use, all of which will alter the global vegetation distribution leading to changes in isoprene emissions. Previous studies have used global chemistry-climate models to assess how possible changes in climate and land use could affect isoprene emissions and hence tropospheric ozone. The chemistry of isoprene oxidation, which can alter the concentration of ozone, is highly complex, therefore it must be parameterised in these models. In this work, we compare the effect of four different reduced isoprene chemical mechanisms, all currently used in Earth system models, on tropospheric ozone. Using a box model we compare ozone in these reduced schemes to that in a more explicit scheme (the Master Chemical Mechanism) over a range of NO x and isoprene emissions, through the use of O 3 isopleths. We find that there is some variability, especially at high isoprene emissions, caused by differences in isoprene-derived NO x reservoir species. A global model is then used to examine how the different reduced schemes respond to potential future changes in climate, isoprene emissions, anthropogenic emissions and land use change. We find that, particularly in isoprene-rich regions, the response of the schemes varies considerably. The wide-ranging response is due to differences in the model descriptions of the peroxy radical chemistry, particularly their relative rates of reaction towards NO, leading to ozone formation, or HO 2 , leading to termination. Also important is the yield of isoprene nitrates and peroxyacyl nitrate precursors from isoprene oxidation. Those schemes that produce less of these NO x reservoir species, tend to produce more ozone locally and less away from the source region. We also note changes in other key oxidants such as NO 3 and OH (due to the inclusion of additional isoprene-derived HO x recycling pathways). These have implications for secondary organic aerosol formation, as does the inclusion of an epoxide formation pathway in one of the mechanisms. By combining the emissions and O 3 data from all of the global model integrations, we are able to construct isopleth plots comparable to those from the box model analysis. We find that the global and box model isopleths show good qualitative agreement, suggesting that comparing chemical mechanisms with a box model in this framework is a useful tool for assessing mechanistic performance in complex global models. We conclude that as the choice of reduced isoprene mechanism may alter both the magnitude and sign of the ozone response, how isoprene chemistry is parameterised in perturbation experiments such as these is a crucially important consideration. More measurements and laboratory studies are needed to validate these reduced mechanisms especially under high-volatile-organiccompound, low-NO x conditions.

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“…Experimental rate constants for ozonolysis of various hydrocarbon alkenes and heteroatom‐substituted alkenes have been obtained by McGillen et al. and have been used to produce a structure–activity relationship (SAR) in conjunction with many existing literature values 36. The reported values of ln( k ) are plotted against Δ H hyd for the hydrocarbon alkenes in Figure 23.…”

Section: Resultsmentioning

confidence: 99%

Electrophilic Addition to Alkenes: The Relation between Reactivity and Enthalpy of Hydrogenation: Regioselectivity is Determined by the Stability of the Two Conceivable Products

Schnatter

Rogers

Zavitsas

2015

Chemistry A European J

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Although electrophilic addition to alkenes has been well studied, some secrets still remain. Halogenations, hydrohalogenations, halohydrin formations, hydrations, epoxidations, other oxidations, carbene additions, and ozonolyses are investigated to elucidate the relation of alkene reactivities with their enthalpies of hydrogenation (ΔHhyd ). For addition of electrophiles to unconjugated hydrocarbon alkenes, ln(k) is a linear function of ΔHhyd , where k is the rate constant. Linear correlation coefficients are about 0.98 or greater. None of the many previously proposed correlations of ln(k) with the properties of alkenes or with linear free-energy relationships match the generality and accuracy of the simple linear relationship found herein. A notable exception is acid-catalyzed hydration in water or in solvents stabilizing relatively stable carbocation intermediates (e.g., tertiary, benzylic, or allylic). (13) C NMR chemical shifts of the two alkene carbons also predict regioselectivity. These effects have not been noted previously and are operative in general, including addition to heteroatom-substituted alkenes.

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Structure–activity relationship (SAR) for the prediction of gas-phase ozonolysis rate coefficients: an extension towards heteroatomic unsaturated species

Cited by 37 publications

References 32 publications

Temperature‐dependent kinetics for the ozonolysis of selected chlorinated alkenes in the gas phase

Temperature‐dependent kinetics for the ozonolysis of selected chlorinated alkenes in the gas phase

Influence of isoprene chemical mechanism on modelled changes in tropospheric ozone due to climate and land use over the 21st century

Electrophilic Addition to Alkenes: The Relation between Reactivity and Enthalpy of Hydrogenation: Regioselectivity is Determined by the Stability of the Two Conceivable Products

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