10027-72-2Relevant academic research and scientific papers
Mechanism of the Ozonolysis of Ethylene-Acetaldehyde Mixtures
Choe, Jong-In,Painter, M. Kimberly,Kuczkowski, Robert L.
, p. 2891 - 2895 (1984)
Ethylene-1,1-d2 was ozonized in the presence of acetaldehyde.The yields of ethylene ozonide-d0, -d2, and -d4 and propylene ozonide-d0, and -d2 were determined by proton NMR, microwave spectroscopy, and manometric measurements.The ratio of propylene ozonide-d0/propylene ozonide-d2 decreased as the concentration of acetaldehyde increased.This indicates that an inverse kinetic secondary isotope effect is associated with the recombination reactions of the carbonyl oxide (Criegee intermediate).A kinetic model was employed to describe the Criegee reaction mechanism and to estimate the final product ratios.This model resulted in quantitative estimates of the KSIE for the carbonyl oxide, the relative dipolarophilicity of formaldehyde and acetaldehyde, and the cage effect upon primary ozonide decomposition.The inverse KSIE for the carbonyl oxide and formaldehyde in their recombination reaction is consistent with a concerted process.
Gas-phase ozonolysis of ethene in the presence of hydroxylic compounds
Neeb,Horie,Moortgat
, p. 721 - 730 (1996)
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.
Kinetic and Mechanistic Study of the Self Reaction of CH3OCH2O2 Radicals at Room Temperature
Jenkin, Michael E.,Hayman, Garry D.,Wallington, Timothy J.,Hurley, Michael D.,Ball, James C.,et al.
, p. 11712 - 11723 (1993)
The UV absorption spectrum and kinetics of the self reaction of CH3OCH2O2 at 298 K have been studied using both the modulated photolysis of Cl2/CH3OCH3/O2/N2 mixtures and the pulse radiolysis of SF6/CH3OCH3/O2 mixtures.The spectrum, characterized in the range 200-290 nm, is in good agreement with the single published determination.The observed second-order removal kinetics of CH3OCH2O2, k5obs, were found to be sensitive to both the variation of total pressure (17-760 Torr) and the composition of the reaction mixtures: 2CH3OCH2O2 -> 2CH3OCH2O + O2 (5a); -> CH3OCHO + CH3OCH2OH + O2 (5b).The kinetic studies and a detailed product investigation using long path length FTIR spectroscopy (T = 295 K; Cl2/CH3OCH3/O2/N2 system) provide evidence to support a mechanism involving the rapid thermal decomposition of CH3OCH2O by H atom ejection occurring in competition with the reaction with O2: CH3OCH2O (+M) -> CH3OCHO + H (+M) (6); CH3OCH2O + O2 -> CH3OCHO + HO2 (4).The complications in the measured values of k5obs in the present studies, and those reported previously, are believed to occur as a direct result of formation of H atoms from reaction 6.Accordingly, a pressure-independent value of k5 = (2.1 +/- 0.3)E-12 cm3 molecule-1 s-1 is derived for the elementary rate coefficient at 298 K, with identical values of the branching ratio α = k5a/k5 = 0.7 +/- 0.1 determined independently from the FTIR product studies and the modulated photolysis experiments.As part of this work, the rate coefficient for the reaction of Cl atoms with CH3OCH2Cl was found to be (2.9 +/- 0.2)E-11 cm3 molecule-1 s-1.
Oligomerization reaction of the Criegee intermediate leads to secondary organic aerosol formation in ethylene ozonolysis
Sakamoto, Yosuke,Inomata, Satoshi,Hirokawa, Jun
, p. 12912 - 12921 (2013)
Ethylene ozonolysis was investigated in laboratory experiments using a Teflon bag reactor. A negative ion chemical ionization mass spectrometer (NI-CIMS) using SO2Cl- and Cl- as reagent ions was used for product analysis. In addition to the expected gas-phase products, such as formic acid and hydroperoxymethyl formate, oligomeric hydroperoxides composed of the Criegee intermediate (CH2OO) as a chain unit were observed. Furthermore, we observed secondary organic aerosol (SOA) formation from the ethylene ozonolysis, and the particle-phase products were also analyzed by NI-CIMS. The CH2OO oligomers were also observed as particle-phase components, suggesting that the oligomeric hydroperoxides formed in the gas phase partition into the particle phase. By adding methanol as a stabilized Criegee intermediate scavenger, both the gas-phase oligomer formation and SOA formation were strongly suppressed. This indicates that CH2OO plays a critical role in the formation of oligomeric hydroperoxides followed by SOA formation in ethylene ozonolysis. A new formation mechanism for the oligomeric hydroperoxides, which includes sequential addition of CH2OO to hydroperoxides, is proposed.
Dimethyl Ether Oxidation: Kinetics and Mechanism of the CH3OCH2 + O2 Reaction at 296 K and 0.38-940 Torr Total Pressure
Sehested, J.,Moegelberg, T.,Wallington, T. J.,Kaiser, E. W.,Nielsen, O. J.
, p. 17218 - 17225 (1996)
The title reaction was studied at 296 K and 0.38-940 Torr total pressure using a FTIR smog chamber technique.The overall rate constant for reaction of CH3OCH2 radicals with O2 may be written, k1 = kRO2 + kprod, where kRO2 is the rate constant for peroxy radical production and kprod is the rate constant for the production of other species from reaction 1. k1 was measured relative to the pressure independent reaction of CH3OCHJ2 radicals with Cl2 (k4).There was no discernible effect of pressure on k1 in the range 200 - 940 Torr.Between 200 and 2 Torr total pressure k1 decreased by approximately a factor of 2.For pressures below 2 Torr k1 was again independent of pressure.The reaction proceeds via the formation of an activated complex, CH3OCH2O2(excit.), that is either collisionally stabilized to form the peroxy radical, CH3OCH2O2, or undergoes intramolecular H-atom abstraction followed by decomposition to give two formaldehyde molecules and an OH radical: CH3OCH2 + O2 ->/ CH3OCH2O2 + M, CH3OCH2O2(excit.) -> CH2OCH2O2H(excit.) -> 2HCHO + OH.The products from this reaction were studied as a function of total pressure.The molar yield of formaldehyde increased from RO2,0/k4 = (1.97 +/- 0.28)E-19 cm3 molecule-1, kRO2,infinite/k4 = 0.108 +/- 0.004, and kprod.0/k4 = (6.3 +/- 0.5)E-2 where kRO2.0 and kRO2.infinite are the overall termolecular and bimolecular rate constants for formation of the CH3OCH2O2 radical and kprod.0 represents the bimolecular rate constant for the reaction of CH3OCH2 radicals with O2 to yield formaldehyde in the limit of low pressure.These data and absolute rate data from the literature were used to derive a rate constant for the reaction of CH3OCH2 radicals with Cl2 of (1.00 +/- 0.16)E-10 cm3 molecule-1 s-1.The results are discussed in the context of the use of dimethyl ether as an alternative diesel fuel.
Ozonolyses of Selected Vinyl Ethers
Griesbaum, Karl,Kim, Woo-Sun
, p. 5574 - 5577 (2007/10/02)
Ozonolyses of the 1-substituted methyl vinyl ethers 5, 8, and 16, bearing bulky substituents, and of the 2-substituted and 2,2-disubstituted methyl vinyl ethers 25 and 30, respectively, afforded the corresponding ozonides which have been isolated and characterized.In most cases, dry ozonolysis on polyethylene was advantageous over ozonolysis in solution.Ozonolysis of the 1,2,2-trisubstituted vinyl ether 34 gave no ozonide under either conditions.
Synthesis of 1,2-Dioxolanes by Ozonolysis of 1,1-Disubstituted Nonactivated Olefins
Reiser, Ralf,Seeboth, Rolf-Guenter,Sueling, Carsten,Wagner, Gabriele,Wang, Jinkai,Schroeder, Gerhard
, p. 191 - 195 (2007/10/02)
Ozonolyses of the cyclopropyl-substituted olefins 2a, 2b, and 2c do not produce the carbonyl oxides 1a, 1b, and 1c but formaldehyde oxide (1d); 1d can be trapped by the starting olefin and provides the 1,2-dioxolanes 6a, 6b, and 6c, respectively, in ca. 10percent yield.Other dioxolanes and normal ozonides may be obtained by the addition of olefins or aldehydes to solutions of the primary ozonides of 2a and 2b.Key-Words: Ozonolysis / Alkylidenecycloalkanes / Carbonyl oxides / 1,2-Dioxolanes / 1,2,4-Trioxolanes
Ozonolyses of α-Oxo-alkenes: On the Existence of α-Oxo-ozonides
Griesbaum, Karl,Greunig, Hans-Joachim,Volpp, Willi,Jung, In-Chan
, p. 947 - 956 (2007/10/02)
Ozonolyses of nine acyclic (1a-i) and two cyclic (14, 29) α-oxo-alkenes on polyethylene or in pentane afforded in eight cases (1d-i, 14, 29) isolable α-oxo-ozonides. α-Diozonides (9) are obtained from five of the acyclic α-oxo-alkenes (1a, b, d, g, h).All isolated ozonides are labile; the 2,4-dinitrophenylhydrazones of the α-oxo-ozonides, however, are very stable.Decomposition of the α-oxo-ozonides affords not only the hitherto known fragments, but non-peroxidic isomers (8) of the ozonides, too.
Synthesis of 1,2,4-Dioxazolidines by the Ozonolysis of Vinyl Ethers in the Presence of Imines. The First Cycloaddition of Carbonyl Oxide to the Carbon-Nitrogen
Mori, Mitsuyuki,Nojima, Masatomo,Kusabayashi, Shigekazu,McCullough, Kevin J.
, p. 1550 - 1552 (2007/10/02)
Carbonyl oxides, derived from the ozonolysis of vinyl ethers, readily undergo cycloaddition reactions with imines affording 1,2,4-dioxazolidines in good yield.
About the Ozone Cleavage of Chloroprene and of 2-Chloro-3-methyl-1,3-butadiene in Methanol
Griesbaum, Karl,Meister, Martin
, p. 1573 - 1580 (2007/10/02)
Monoozonolyses of chloroprene (1a) and of 2-chloro-3-methyl-1,3-butadiene (1b) in methanol occur with more than 90percent at the non-chlorinated double bonds to afford the corresponding α,β-unsaturated oxo compounds 2 with selectivities of 96 and 80percent respectively.The latter subsequently react with methanol, and 2a also with the complementary fragment methoxymethyl hydroperoxide (5).The α,β-unsaturated methoxy hydroperoxides 3 which have also been obtained, are less stable than similarly structured, non-α-chlorinated methoxy hydroperoxides.Diozonolyses of 1a and 1b in methanol afforded in 50-60percent the corresponding α-oxocarboxylates (21) and/or the corresponding ketals.In addition, anomalous products were obtained viz. ca. 15percent of methyl hydroxyacetate (12d) from 1a and 1b, as well as ca. 30percent of dimethyl oxalate (27b) from 1a and ca. 35percent of methyl acetate (13) from 1b.The modes of formation of these products have been postulated according to model reactions.
