Gas phase kinetics for the ozonolysis of n-butyl methacrylate, ethyl crotonate and vinyl propionate under atmospheric conditions (original) (raw)
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The kinetics and products of the gas-phase reactions of ozone with methyl methacrylate, methyl acrylate, and ethyl acrylate have been investigated at 760 Torr total pressure of air and 294 (2 K. The rate coefficients obtained (in cm 3 molecule-1 s-1 units) were as follows: k(methyl methacrylate)) (6.7 (0.9) × 10-18 , k(methyl acrylate)) (0.95 (0.07) × 10-18 , and k(ethyl acrylate)) (1.3 (0.1) × 10-18. In addition to formaldehyde being observed as a product of the three reactions, the other major reaction products were methyl pyruvate from reaction of ozone with methyl methacrylate, methyl glyoxylate from reaction of ozone with methyl acrylate, and ethyl glyoxylate from reaction of ozone with ethyl acrylate. Possible reaction mechanisms leading to the observed products are presented and discussed.
International Journal of Chemical Kinetics, 1998
Rate constants for the reaction of ozone with methylvinyl ketone (H 2 C " CHC(O)CH 3 ), methacrolein (H 2 C" C(CH 3 )CHO), methacrylic acid (H 2 C "C(CH 3 )C(O)OH), and acrylic acid (H 2 C " CHC(O)OH) were measured at room temperature in the pres-(296 Ϯ 2 K) ence of a sufficient amount of cyclohexane to scavenge OH-radicals. Results from pseudofirst-order experiments in the presence of excess ozone were found not to be consistent with relative rate measurements. It appeared that the formation of the so-called Criegee-intermediates leads to an enhanced decrease in the concentration of the two organic acids investigated. It is shown that the presence of formic acid, which is known to react efficiently with Criegee-intermediates, diminishes the observed removal rate of the organic acids. The rate constant for the reaction of ozone with the unsaturated carbonyl compounds methylvinyl ketone and methacrolein was found not to be influenced by the addition of formic acid. Rate constants for the reaction of ozone determined in the presence of excess formic acid are in ): methylvinyl ketone methacrolein 3 Ϫ1 Ϫ1 Ϫ18 cm molecule s (5.4 Ϯ 0.6) ϫ 10 ; (1.3 Ϯ 0.14) ϫ methacrylic acid and acrylic acid Results are Ϫ18 Ϫ18 Ϫ18
Journal of Physical Chemistry A, 1997
A detailed kinetic analysis of the complex reaction systems arising from the ozonolysis of C 2 H 4 and (CH 3 ) 2 CdC(CH 3 ) 2 (TME), respectively, is carried out, using master equations and statistical rate theory. The thermochemical as well as the molecular data required are obtained from CCSD(T)/TZ2P and B3LYP/ DZP calculations. It is shown that the primary ozonides are not collisionally stabilized under atmospheric conditions. In the reaction sequence for O 3 + TME, the same is true for CH 2 dC(CH 3 )OOH formed from (CH 3 ) 2 COO, which completely dissociates to give OH radicals. However, in this system, a pressure dependence is predicted for the relative branching fractions of the reactions of the Criegee intermediate. Under atmospheric conditions, for both examples, the product yields obtained are in reasonable agreement with experimental results.
Simulation chamber investigation of the reactions of ozone with short-chained alkenes
Journal of Geophysical Research, 2007
Reaction rate coefficients and product yields in the gas phase reaction of O3 with the short-chained alkenes ethene, propene, 1-butene, isobutene, (E)-butene, and (Z)-butene were determined by Simulation of Atmospheric Photochemistry in a Large Reaction Chamber (SAPHIR). In a first set of experiments, reaction rate coefficients were acquired in an absolute reaction rate study from the measured concentration time profiles of ozone and the alkenes with side reactions being suppressed by adding a radical scavenger. The rate coefficients obtained agree well with literature data; for all but one alkene, the deviation was less than 10%. In a second set of experiments, OH yields were derived from the additional alkene turnover in the absence of a radical scavenger. In contrast to other studies, the OH yields determined in the dry chamber (propene, 0.10 ± 0.07; 1-butene, 0.00 ± 0.08, isobutene, 0.30 ± 0.14; (Z)-butene, 0.18 ± 0.09; and (E)-butene, 0.70 ± 0.12) differed from the yields obtained under humid conditions (propene, 0.30 ± 0.08; 1-butene, 0.30 ± 0.09; isobutene, 0.80 ± 0.10; (Z)-butene, 0.40 ± 0.05; and (E)-butene, 0.60 ± 0.12). The only exception was ethene ozonolysis, where no OH production was observed. HO2 yields (propene, 1.50 ± 0.75; 1-butene, 1.60 ± 0.80; and isobutene, 2.00 ± 1.00) estimated from the additional ozone turnover compared to the experiments where radicals were not scavenged are reported here for the first time. Furthermore, the yields of the stable ozonolysis products CO, acetaldehyde, and formaldehyde were acquired by monitoring the concentration time profile of the respective compound.
Kinetics of heterogeneous ozone reactions
Chemosphere, 2000
Earlier results on ozone destruction on solid surfaces gave apparent ®rst order kinetics. Estimating the reaction kinetics from our data on ozone destruction on various powders (silica-gel, alumina, wood ash, coal ash, Saharan sand, calcite), we found that only calcite and wood ash exhibited such a behaviour. Removal of ozone by other powders used showed two straight lines in ln c±t plot with two dierent half-lives, t H 1a2`t HH 1a2 . Comparing the kinetic constants for ozone removal on silica-gel and that of ozone reactions with polynuclear aromatic hydrocarbons (PAHs) adsorbed in submonolayer coverage on the same powder, the ®rst reaction seems to be more likely in the case of pyrene and particularly¯uoranthene. Enhanced ozone destruction on airborne aerosols could be an additional reason for¯uoranthene stability in the real atmosphere. Ó
Absolute rate constants for the gas-phase ozonolysis of isoprene and methylbutenol
International Journal of Chemical Kinetics, 2004
The reactions of the biogenic organic compounds isoprene and 2-methyl-3buten-2-ol (MBO) with ozone have been investigated under controlled conditions for pressure (atmospheric pressure) and temperature (293 ± 2 K), using FTIR spectrometry. CO was added to scavenge hydroxyl radical formation during the ozonolysis experiments. Reaction rate constants were determined by absolute rate technique, by measuring both ozone and the organic compound concentrations. The measured values were k 1 = (1.19 ± 0.09) × 10 −17 cm 3 molecule −1 s −1 for the reaction between ozone and isoprene and k 2 = (8.3 ± 1.0) × 10 −18 cm 3 molecule −1 s −1 for the reaction between ozone and MBO. C 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: [152][153][154][155][156] 2004
Zeitschrift für Physikalische Chemie, 2010
The gas-phase ozonolysis of the biogenic unsaturated compounds 1-penten-3-ol, (Z)-2-penten-1-ol and 1-penten-3-one has been investigated in two atmospheric simulation chambers. The following rate coefficients (in units of 10 K17 cm 3 molecule K1 s K1 ) were determined at atmospheric pressure and 293±2 K using an absolute rate method: 1-penten-3-ol, (1.64±0.15); (Z)-2penten-1-ol, (11.5±0.66); 1-penten-3-one, (1.17±0.15). Reaction products were identified by in situ FTIR spectroscopy and gas chromatographymass spectrometry (GC-MS). The major products and their average molar yields in the presence of a radical scavenger at relative humidity < 1% were: formaldehyde (0.49±0.02), 2-hydroxybutanal (0.46±0.03) and propanal (0.15±0.02) from 1-penten-3-ol; propanal (0.39±0.03) and glycolaldehyde (0.43±0.04) from (Z)-2-penten-1-ol; formaldehyde (0.37±0.02) and 2-oxobutanal (0.49±0.03) from 1-penten-3one. The formation of secondary organic aerosol was also observed with yields ranging from 0.13-0.17 for the unsaturated alcohols. Significantly lower yields of around 0.03 were measured for 1-penten-3-one. The results of this work are used to determine atmospheric lifetimes and reaction mechanisms for the gas-phase ozonolysis of 1-penten-3-ol, (Z)-2-penten-1-ol and 1penten-3-one. The broader atmospheric implications of this work are also discussed.
Journal of Atmospheric Chemistry, 2006
This article presents a complete study of the diurnal chemical reactivity of the biogenic volatile organic compound (BVOC), 2-methyl-3-buten-2-ol (MBO) in the troposphere. Reactions of MBO with OH and with ozone were studied to analyse the respective parts of both processes in the global budget of MBO atmospheric reactivity. They were investigated under controlled conditions for pressure (atmospheric pressure) and temperature (298 ± 2 K) using three complementary European simulation chambers. Reaction with OH radicals was studied in the presence of and in the absence of NO x . The kinetic study was carried out by relative rate study using isoprene as a reference. The rate constant found for this reaction was k MBOþOH ¼ 5:6 AE 0:6 ð ÞÂ10 À11 molecule −1 cm 3 s −1 . FTIR spectroscopy, DNPH-and PFBHA-derivatisation analyses were performed for reactions with both OH radicals and ozone. In both reactions, the hydroxycarbonyl compound, 2-hydroxy-2-methylpropanal (HMPr) was positively identified and quantified, with a yield of R HM Pr ¼ 0:31 AE 0:11 in the reaction with OH, and a yield of R HM Pr ¼ 0:43 AE 0:12 and 0.84±0.08 in the reaction with ozone under dry (HR<1%) and humid conditions (HR=20%-30%). A primary production of two other carbonyl compounds, acetone R acetone ¼ 0:39 AE 0:22, and formaldehyde R HCHO ¼ 0:44 AE 0:05 was found in the case of the dry ozonolysis experiments. Under humid conditions, only formaldehyde was co-produced with HMPr as a primary carbonyl compound, with a yield of R HCHO ¼ 0:55 AE 0:03. For the reaction with OH, three other carbonyl compounds were detected, acetone R acetone ¼ 0:67 AE 0:05, formaldehyde R HCHO ¼ 0:33 AE 0:08 and glycolaldehyde R glycolaldehyde ¼ 0:78 AE 0:20. In addition some realistic photo-oxidation experiments were performed to understand in an overall way the transformations of MBO in the atmosphere. The realistic photo-oxidation experiments were conducted in the EUPHORE J Atmos Chem outdoor simulation chamber. It was found that this compound is a weak secondary aerosol producer (less than 1% of the carbon balance). But it was confirmed that it is a potentially significant source of acetone, Δ[Acetone]/Δ[MBO]=0.45. With our experimental conditions ([MBO] 0 =200 ppb, [NO]o=50 ppb), an ozone yield of Δ[O 3 ]/Δ[MBO]=1.05 was found.
Journal of The American Chemical Society, 1981
The stable products of the low-pressure (4-8 torr (1 torr = 133.33 Pa)) gas-phase reactions of ozone with ethene, propene, 2-methylpropene, cis-2-butene, trans-2-butene, trans-2-pentene, 2,3-dimethyl-2-butene, and 2-ethyl-1 -butene have been identified by using a photoionization mass spectrometer coupled to a stirred-flow reactor. The products observed are characteristic of (i) a primary Criegee split to an oxoalkane (aldehyde or ketone) and a Criegee intermediate,
Chemical Physics Letters, 2015
Relative rate coefficients of the reactions of O 3 with (Z)-3-hexen-1-ol, (E)-3-hexen-1-ol and (E)-2hexen-1-ol have been determined in an environmental chamber with in situ FTIR detection of the reactants at 298 K and 760 Torr. The following rate coefficients (in units of 10 −17 cm 3 molecule −1 s −1 ) have been determined: (6.04 ± 0.95) for (Z)-CH 2 (OH)CH 2 CH CHCH 2 CH 3 ; (5.83 ± 0.86) for (E)-CH 2 (OH)CH 2 CH CHCH 2 CH 3 ; (5.98 ± 0.73) for (E)-CH 2 (OH)CH CH(CH 2 ) 2 CH 3 . This is the first kinetic study for the reactions of O 3 with (E)-2-hexen-1-ol and (E)-3-hexen-1-ol. Reactivity trends are developed and the atmospheric persistence of these compounds is calculated based on the rate coefficients. .ar (M.A. Teruel).