1558-67-4Relevant articles and documents
Mechanism of the Ozone-Ethene Reaction in Dilute N2/O2 Mixtures Near 1-atm Pressure
Kan, Charles S.,Su, Fu,Calvert, Jack G.,Shaw, John H.
, p. 2359 - 2363 (1981)
Kinetic studies of the O3-C2H4 reaction (ppm reactant level in 700 torr of O3/N2) were made at several temperatures (9-30 deg C) by using Fourier transform-infrared methods to follow reactants and products in situ.The rate data gave the second-order rate constant for the elementary reaction O3 + C2H4 ---> ---> CH2OO* + CH2O (1); k1 (cm3molecule-1s-1)=10-13.59+/-0.27exp.The fraction of the CH2OO* species formed in eq 1 which does not fragment, but lives to react with CH2O, was found to be 0.37+/-0.02, independent of temperature (9-30 deg C).The addition of CH2O2 to CH2O leads to the transient product X, thought to be HOCH2OCHO, and this produces formic anhydride by some ill-defined path (e.g., HOCH2OCHO ---> (HCO)2O + H2 (7); or HOCH2OCHO + O2 ---> (HCO)2O + H2O2 (7a)).The first-order rate constant k7 showed an unexpected, low activation energy and preexponential factor and a sensitivity to wall conditioning and O2 pressure which suggested that reaction 7, 7a, or some similar reaction forming (HCO)2O occurs heterogeneously.
Temperature dependence of the alpha-ester rearrangement reaction
Tyndall, Geoffrey S.,Pimentel, Andre S.,Orlando
, p. 6850 - 6856 (2004)
Measurements have been made of the oxidation products of methyl formate and methyl acetate as a function of temperature (253-324 K). Both processes show the occurrence of the α-ester rearrangement channel RC(O)OCH 2O→ RC(O)OH + HCO, which has an activation energy of ～10 kcal mol-1. Reaction of hydroxyl radicals with methyl formate occurs with roughly equal efficiency at both of the carbon atoms, while OH-reaction with methyl acetate leads to 30-40% attack at the acetate group.
Kinetic and Product Study of the Atmospheric Photooxidation of 1,4-Dioxane and Its Main Reaction Product Ethylene Glycol Diformate
Maurer, Tobias,Hass, Heinz,Barnes, Lan,Becker, Karl H.
, p. 5032 - 5039 (1999)
A FTIR kinetic and product study of the OH-radical initiated oxidation of 1,4-dioxane (DOX) has been performed in a quartz-glass photoreactor in the laboratory under different conditions and also in the outdoor EUPHORE simulation chamber in Valencia, Spain. Using the relative kinetic technique, a rate coefficient of k = (1.24 ± 0.04) × 10-11 cm3 molecule-1 s-1 was determined for the reaction at 298 K in 1000 mbar of synthetic air, which is in good agreement with other published values. The major reaction product both in the presence and absence of NO was ethylene glycol diformate (EDF). This compound has been synthesized, and authentic samples have been used for calibration. Integrated band intensities have been calculated for the three strongest bands of EDF: (4.99 ± 0.06) × 10-17 cm molecule-1 for 1100-1225 cm-1, (3.90 ± 0.05) × 10-17 cm molecule-1 for 1670-1820 cm-1, (9.34 ± 0.11) × 10-18 cm molecule-1 for 2775-3075 cm-1. In the laboratory reactor, yields for EDF of 87 ± 9 and 95 ± 10 mol % were obtained using the photolysis of MeONO/NO/air and H2O2/NO/air as the OH radical sources, respectively. Using only the photolysis of H2O2/ air as the OH source resulted in a molar yield of 55 ± 6 mol % for EDF. In the outdoor EUPHORE simulation chamber a yield of 95 ± 10 mol % was obtained from irradiation of a DOX/NOx/air mixture. The OH-radical- and Cl-atom-initiated oxidation of EDF has also been investigated. Rate coefficients of kOH = (4.72 ± 0.31) × 10-13 cm3 molecule-1 s-1 and kcl = (3.52 ± 0.09) × 1012 cm3 molecule-1 s-1 have been determined for the reaction of EDF with OH radicals and Cl atoms, respectively, at 298 K and 1000 mbar total pressure. The products determined in the Cl-initiated oxidation in the presence of NOx were formic acid anhydride (FAA), formic acid (FA), and carbon monoxide (CO) with yields of 173 ± 34 mol %, 45 ± 9 mol %, and 41 ± 8 mol %, respectively. Formation of a peroxy formyl nitrate was also observed. In the absence of NOx the yields of FAA, FA and CO were 144 ± 29 mol %, 39 ± 8 mol %, and 22 ± 4 mol %, respectively.
Infrared Spectra and Photochemistry of the Primary and Secondary Ozonides of Propene, trans-2-Butene, and Methylpropene in Solid Argon
Andrews, Lester,Kohlmiller, Christopher K.
, p. 4548 - 4557 (1982)
Reactions of propene, trans-2-butene, and methylpropene with 16O3, 16,18O3,and 18O3 have been studied in solid xenon at 80 - 100 K and CF3Cl solution at 130 - 150 K.The major reaction product in solution was identified as the secondary ozonide (SOZ) from the matrix infrared spectrum.Reaction products in solid xenon for propene and trans-2-butene were SOZ, primary ozonide (POZ), and aldehyde, and for methyl propene the products were POZ, oxide, and acetone.The POZ's were characterized by an intense antisymmetric O-O-O stretching mode at 640 - 700 cm-1.Photolysis of the propene and 2-butene SOZ's gave formic acetic anhydride, hydroxy ester, and acid-aldehyde dimer decomposition products.
Atmospheric degradation of glycidaldehyde: Photolysis and reaction with OH radicals
Ma,Barnes,Becker
, p. 3515 - 3521 (1998)
Epoxide aldehydes have recently been detected among the oxidation products of aromatic hydrocarbons. Many epoxides are toxic and very little is known about their atmospheric fate. The products and kinetics of the atmospheric oxidation, OH radical reaction, and photolysis of glycidaldehyde have been investigated in a large volume reactor at 298 K using in situ long- path FT-IR spectroscopy for the analysis. A rate coefficient of k = (1.69 ± 0.04) x 10-11 cm3 molecule-1 s-1 has been determined for the reaction of glycidaldehyde with the OH radical using the relative kinetic technique. The UV absorption spectrum of glycidaldehyde was measured in the range 220380 nm from which upper limits of its photolysis frequencies in the troposphere have been deduced, e.g., J (hv) ~ 1.0 x 10-4 s-1 (for July 1, noon, and 50°N). The OH radical initiated photooxidation of glycidaldehyde yields CO, CO2, formic acid, formic acid anhydride, formaldehyde, and hydroperoxymethyl formate as major products. A reaction mechanism is postulated to account for the product formation. Epoxide aldehydes have recently been detected among the oxidation products of aromatic hydrocarbons. Many epoxides are toxic and very little is known about their atmospheric fate. The products and kinetics of the atmospheric oxidation, OH radical reaction, and photolysis of glycidaldehyde have been investigated in a large volume reactor at 298 K using in situ long-path FT-IR spectroscopy for the analysis. A rate coefficient of k = (1.69 ± 0.04) × 10-11 cm3 molecule-1 s-1 has been determined for the reaction of glycidaldehyde with the OH radical using the relative kinetic technique. The UV absorption spectrum of glycidaldehyde was measured in the range 220-380 nm from which upper limits of its photolysis frequencies in the troposphere have been deduced, e.g., J(hv) approx. 1.0 × 10-4 s-1 (for July 1, noon, and 50° N). The OH radical initiated photooxidation of glycidaldehyde yields CO, CO2, formic acid, formic acid anhydride, formaldehyde, and hydroperoxymethyl formate as major products. A reaction mechanism is postulated to account for the product formation.
FT IR Spectroscopic Study of the Ozone-Ethene Reaction Mechanism in O2-Rich Mixtures
Su, Fu,Calvert, Jack G.,Shaw, John H.
, p. 239 - 246 (1980)
Fourier transform infrared spectroscopy has been employed to study the kinetics and products of the reaction between ozone and ethene (C2H2, cis-CDHCDH, trans-CDHCDH, and C2D2) in the ppm range in gaseous O2-N2 mixtures (18-26 deg C, 700 torr).In addition
The atmospheric oxidation of ethyl formate and ethyl acetate over a range of temperatures and oxygen partial pressures
Orlando, John J.,Tyndall, Geoffrey S.
experimental part, p. 397 - 413 (2011/08/09)
The Cl-atom-initiated oxidation of two esters, ethyl formate [HC(O)OCH 2CH3] and ethyl acetate [CH3C(O)OCH 2CH3], has been studied at pressures close to 1 atm as a function of temperature (249-325 K) and O2 partial pressure (50-700 Torr), using an environmental chamber technique. In both cases, Cl-atom attack at the CH2 group is most important, leading in part to the formation of radicals of the type RC(O)OCH(O?)CH3 [R = H, CH3]. The atmospheric fate of these radicals involves competition between reaction with O2 to produce an anhydride compound, RC(O)OC(O)CH3, and the so-called α-ester rearrangement that produces an organic acid, RC(O)OH, and an acetyl radical, CH3C(O). For both species studied, the α-ester rearrangement is found to dominate in air at 1 atm and 298 K. Barriers to the rearrangement of 7.7 ± 1.5 and 8.4 ± 1.5 kcal/mole are estimated for CH3C(O)OCH(O?)CH3 and HC(O)OCH(O?)CH3, respectively, leading to increased occurrence of the O2 reaction at reduced temperature. The data are combined with those obtained from similar studies of other simple esters to provide a correlation between the rate of occurrence of the α-ester rearrangement and the structure of the reacting radical.
An Experimental and Computational Study of the Kinetics and Mechanism of the Reaction of Methyl Formate with Cl Atoms
Good, David A.,Hansen, Jaron,Kamoboures, Mike,Santiono, Randy,Francisco, Joseph S.
, p. 1505 - 1511 (2007/10/03)
Ab initio molecular orbital theory has been used to examine the kinetics and mechanism for the reaction of chlorine atoms with methyl formate. From the ab initio parameters, the room-temperature rate constant is calculated and found to be in reasonable agreement with the experimental determination. It is found that 90% of the reaction proceeds via abstraction of the carbonyl hydrogen from methyl formate by chlorine atoms, resulting in the formation of CH3OCO radical.
Gas-phase ozonolysis of ethene in the presence of hydroxylic compounds
Neeb,Horie,Moortgat
, p. 721 - 730 (2007/10/03)
Ozonolysis of C2H4 was carried out at 295 K in 730 torr synthetic air, both in the absence and presence of the added HCOOH, CH3COOH, and CH3OH. Results of this study together with the formation of HC-CH2OOH, with added water vapor were explained by the reaction of the Criegee biradical CH2OO with the added hydroxy compounds ROH. Formation of the products with the general formula R-O-CH2 indicates that the RO-H bond fission has taken place.
FTIR Spectroscopic Study of the Cl-Atom-Initiated Reactions of Ethylene Oxide in O2/N2 Diluent
Chen, J.,Young V.,Hooshiyar, P. A.,Niki, H.,Hurley, M. D.
, p. 4071 - 4077 (2007/10/02)
A long-path FTIR spectroscopic study of the Cl-atom-initiated reactions of ethylene oxide was carried out at 297+/-2 K in the photolysis (300 mn) of mixtures containing and Cl2 in both the torr millitorr ranges in 700 Torr of N2 or O2/N2 diluent.In 700 Torr of N2, the only primary product detected was , formed via (1) Cl+ -> + HCl followed by (2) + Cl2 -> + Cl.Thus, the cyclic oxiranyl radical formed in reaction 1 was sufficiently long-lived to react with Cl2.An upper limit value of k34 s-1 has been esmimated for the rate constant of the possible oxiranyl-to-vinoxy isomerization: (3) -> CH2CHO.The yield decreased with increase in added O2 due to the occurrence of reaction 4: (4) + O2 (+M) -> (+M).A value of k2/k4=2.0+/-0.4 was derived from the O2 dependence of the yield.In 700 Torr of air, the observed products included C-O-C bonded compounds HC(O)OCHO and CH2(OH)OCHO, and one-carbon species CO, CO2, HCHO, and HC(O)OH, but not C-C bonded products.The preferential formation of C-O-C rather than C-C bonded products suggests the predominant cleavage of the C-C bond rather than the C-O bond in a three membered ring precursor radical.The most likely candidate is the cyclic radical formed via self-reaction, i.e. -> + O2.A detailed mechanism is proposed for the oxidation of the radical leading to the formation of the observed products.
