765-57-1Relevant articles and documents
Observation of secondary 2-butene ozonide in the ozonation of trans-2-butene in the gas phase
Fajgar, Radek,Vitek, Josef,Haas, Yehuda,Pola, Josef
, p. 3391 - 3394 (1996)
GC/MS detection of secondary 2-butene ozonide in the gas-phase ozonation of trans-2-butene provides the first conclusive evidence on the feasibility of the combination of Criegee intermediate with parent carbonyl compound, which is not facilitated by solvent.
Infrared matrix isolation and theoretical study of the initial intermediates in the reaction of ozone with cis-2-Butene
Clay, Mary,Ault, Bruce S.
experimental part, p. 2799 - 2805 (2010/10/01)
Matrix isolation studies combined with infrared spectroscopy of the twin jet codeposition of ozone and cis-2-butene into argon matrices have led to the first observation of several early intermediates in this ozonolysis reaction. Specifically, evidence is presented for the formation and identification of the long sought-after Criegee intermediate, as well as confirming evidence for earlier reports of the primary and secondary ozonides. These species were observed after initial twin jet deposition, and grew upon annealing to 35 K. Extensive isotopic labeling (18O and 16,48O mixtures) experiments provided important supporting data. Detailed theoretical calculations at the B3LYP/6-311++G(d,2p) level were carried out as well to augment the experimental work, Merged jet (flow reactor) experiments followed by cryogenic trapping in solid argon led to the formation of "late", stable oxidation products. Photochemical, reactions of ozone with cis-2-butene was studied as well, as was the photochemical behavior of the primary and secondary ozonides.
Formation of secondary ozonides in the gas phase low-temperature ozonation of primary and secondary alkenes
Fajgar, Radek,Vitek, Josef,Haas, Yehuda,Pola, Josef
, p. 239 - 248 (2007/10/03)
The gas-phase ozonation of a series of alkenes RCH=CH2 (R = Et, Hex), trans-RHC=CHR (R = Me, Et, Pri) and Me2C=CMe2 at -40 to 20°C, and that of ethene H2C=CH2 at -120 to 0°C at 10-4 v/v concentrations in N2 at atmospheric pressure have been studied. Using complementary product analysis by means of GC-FTIR and GC-MS techniques, we present conclusive evidence for the formation of secondary alkene ozonides as high-yield products in all instances except Me2C=CMe2. It is shown that the stereoselectivity for the conversion of trans-RHC=CHR (R = Me, Et, Pri) to trans-secondary ozonides in the gas phase is similar to that observed earlier in solution, and that the yields of secondary ozonides from RHC=CH2, but not those from RHC=CHR, significantly decrease with increasing temperature.
Stereochemical Effects in the Ozonolysis of (E)- and (Z)-1-Ethoxypropene
Wojciechowski, Brenda J.,Pearson, William H.,Kuczkowski, Robert L.
, p. 115 - 121 (2007/10/02)
The ozonolysis of (E)-1-ethoxypropene (or (Z)-1-ethoxypropene) gave cis and trans pairs of 1,2-dioxolanes, 1,2,4-trioxolanes (ozonides), and 1,2,4,5-tetroxanes.Ozonolysis of mixtures of the E and Z alkenes led to variation in the dioxolane stereoisomer ratios but not in the trioxolane ratios.Ozonolysis in the presence of added alcohol or aldehydes produced hydroperoxides or ozonides, respectively, from the methyl-substituted carbonyl oxide.The results are consistent with a Criegee ozonolysis mechanism if the two alkenes produce different relative amounts of the syn and anti carbonyl oxide (CH3HCOO), which recombine at different rates with dipolarophiles.
High-Field Rapid Injection NMR: Observation of Unstable Primary Ozonide Intermediates
McGarrity, John F.,Prodolliet, Jacques
, p. 4465 - 4470 (2007/10/02)
A "rapid injection" NMR system is described for use on a 360-MHz superconducting spectrometer.The major advantages of the high-field sytem over our original system are increased sensitivity, resolution, and rapidity.The technique was used to study the ozonolysis of tetramethylethylene and (briefly) cis-but-2-ene, particularly the decomposition of the corresponding primary ozonides 2 and 4, with half-lives of 0.74 and 0.06 s, respectively, at -92 deg C.It was found that the decomposition of 2 in CD2Cl2 (a) had Δ H(excit) = 39 kJ/mol and Δ S(excit) = 28 J/(molK), (b) was unaffected by the presence of TCNE, but (c) was acid-catalyzed.The effects of substituents, solvent, and acid catalysts on the decomposition of primary ozonides are discussed.
MECHANISM OF THE OZONOLYSIS OF PROPENE IN THE LIQUID PHASE.
Choe,Srinivasan,Kuczkowski
, p. 4703 - 4704 (2007/10/02)
Propylene was ozonized in isobutane, hlorodifluoromethane, and methyl chloride solvents. Propylene ozonide, ethylene ozonide, and 2-butene ozonide (cis and trans isomers) were obtained in ratios of about 82:16:2. The amount of butene ozonide increased while that of ethylene ozonide usually decreased for reactions in the presence of added acetaldehyde. The cis-trans stereochemistry of the butene cross ozonide from propylene was studied at various conditions. Usually the cis isomer was preferentially formed, but addition of acetaldehyde could alter this. The cis-(trans-butene ozonide ratio was 67/33 when formed from cis- or trans-2-butene in CHClF//2 and 50/50 as a cross ozonide from trans-2-pentene. The kinetic secondary isotope effects upon ozonolysis of propene-2-d//1 (k//H/k//D equals 0. 88 (6) and propene-1-d//1 (0. 88 (8) were evaluated. These results are discussed with reference to the Criege mechanism of ozonolysis. 37 refs.
The Mechanism of Ozone-Alkene Reactions in the Gas Phase. A Mass Spectrometric Study of the Reactions of Eight Linear and Branched-Chain Alkenes
Martinez, Richard I.,Herron, John T.,Huie, Robert E.
, p. 3807 - 3820 (2007/10/02)
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, (ii) reactions of the Criegee intermediates such as unimolecular decomposition, secondary ozonide formation, etc., and (iii) secondary alkene chemistry involving OH and other free-radical products formed by the unimolecular decomposition of the Criegee intermediates.The secondary OH - alkene - O2 reactions account for a significant fraction of the alkene (CnH2n) consumed and lead to characteristic products such as Cn dioxoalkanes nH2n + 30)>, Cn acyloins nH2n + 32)>, and Cn alkanediols nH2n + 34)>.Cn oxoalkanes and Cn epoxyalkanes observed at m/e (CnH2n + 16) are probably formed primarily via epoxidation of the alkene by O3.A general mechanism has been proposed to account for the observations.
