15454-33-8Relevant articles and documents
Rate Coefficient for the Reaction of CH2OH Radicals with Cl2 and Infrared Spectra of Chloromethanol and Dichloromethanol
Tyndall, Geoffrey S.,Wallington, Timothy J.,Hurley, Michael D.,Schneider, William F.
, p. 1576 - 1582 (1993)
Quantitative infrared spectra have been recorded for chloromethanol and dichloromethanol, formed from the reactions of Cl2 with CH2OH and CHClOH, respectively.Chloromethanol decomposes quantitatively to HCHO and HCl, probably via a heterogeneous mechanism.The lower limit for the homogeneous gas-phase lifetime thus measured is 660 s.The rate coefficient for the reaction of CH2OH with Cl2 has been determined by measuring the products formed in experiments where O2 was allowed to complete with Cl2 for the CH2OH radicals.The rate coefficient is (2.7 +/- 0.7) x 10-11 cm3 molecule-1 s-1 at 295 +/- 2 K.The rate coefficient for the reaction of Cl atoms with chloromethanol was estimated to be (4 +/- 2) x 10-12 cm3 molecule-1 s-1 at 295 +/- 2 K.
Photochemical Processes on Chloromethyl Formate and Vinyl Formate in Low-Temperature Matrices: Infrared Spectra and ab Initio Calculations on Chloromethanol and Vinyl Alcohol
Kunttu, Henrik,Dahlqvist, Martti,Murto, Juhani,Raesaenen, Markku
, p. 1495 - 1502 (1988)
The UV photodecomposition of chloromethyl formate and vinyl formate has been studied in low-temperature noble-gas matrices at wavelengths between 200 and 260 nm.Two distinct channels in cage photolysis were observed: (i) ClH2COCHO -> ClH2COH+CO; H2CCHOCHO -> H2CCHOH+CO. (ii) ClH2COCHO -> H2CO+HCl+CO; H2CCHOCHO -> CH3CHO+CO.There is a well-established wavelength dependence influencing the product ratios in these photochemical processes.Decomposition due to irradiation at wavelength near 250 nm prefers channel i, where the formic acid esters decompose to the corresponding alcoholic species, chloromethanol (a new compound), and vinyl alcohol.On the other hand, at shorter wavelengths, channel ii dominates.Neither chloromethanol nor vinyl alcohol were observed to decompose at wavelengths above 200 nm.The photoprocesses of vinyl formate were also studied in NO-doped Ar matrices as well as in solid Xe in order to get information concerning the mechanisms of photochemical decomposition of formic acid esters.The assignment of the vibrational spectra is based on ab initio calculations performed at the Hartree-Fock 6-13G level for chloromethanol and at the MP2/6-13G** level for vinyl alcohol.A detailed vibrational analysis is given for chloromethanol, chloromethanol-O-d, and vinyl alcohol.
Kinetic study of hydrolysis of benzoates. Part XXIII - Influence of the substituent and temperature on the kinetics of the alkaline hydrolysis of alkyl benzoates in aqueous 2.25 M Bu4NBr and 80% DMSO
Nummert, Vilve,Piirsalu, Mare
, p. 353 - 361 (2007/10/03)
The second-order rate constants k2 (M-1 s-1) for the alkaline hydrolysis of substituted alkyl benzoates, C6H5CO(O)R (R = CH3, CH2Cl, CH2CN, CH2C≡CH, CH2C6H5, CH2CH2Cl, CH2CH2OCH3), were measured in aqueous 2.25 M n-Bu4NBr and in 80% (v/v) DMSO solution at several temperatures. The log k values were analyzed using the equation log k = log k0 + ρσ + δEsB. The EsB scale has been proposed for the steric effect of alkyl substituents in the alkyl part of esters: EsB = (log kR - log kCH(3))H+, where k is the rate constant for the acidic hydrolysis of substituted alkyl benzoates or acetates in water. As polar substituent parameters, both Taft σ* and σI constants were used. The dual parameter treatments of the log k values with σ and EsB constants gave excellent correlations (R = 0.997). For 2.25 M n-Bu4NBr, 80% (v/v) DMSO and pure water at 25 °C, calculated susceptibilities to the inductive effect of alkyl substituents ρ* were found to be 2.07, 2.21 and 1.64, respectively. The corresponding ρI values were 4.64, 4.94 and 3.64. The dependence of ρI on solvent and temperature in the alkaline hydrolysis of substituted alkyl benzoates was similar to that observed earlier for meta- and para-substituents in the alkaline hydrolysis of substituted phenyl benzoates and tosylates. The substituent dependence of the activation energy, E, was found to be completely caused by the polar effect. Susceptibility to steric effect in the alkaline hydrolysis of alkyl benzoates (δ ≈ 1) appeared to be independent of the solvent and temperature. Copyright
Kinetics of the cross reactions of CH3O2 and C2H5O2 radicals with selected peroxy radicals
Villenave, Eric,Lesclaux, Robert
, p. 14372 - 14382 (2007/10/03)
The kinetics of the reactions of selected peroxy radicals (RO2) with CH3O2 and with C2H5O2 have been investigated using two techniques: excimer-laser photolysis and conventional flash photolysis, both coupled with UV absorption spectrometry. Radicals were generated either by photolysis of molecular chlorine in the presence of suitable hydrocarbons or by photolysis of the appropriate alkyl chloride. All such cross-reaction kinetics were investigated at 760 Torr total pressure and room temperature except for the reaction of the allylperoxy radical with CH3O2, for which the rate constant was determined between 291 and 423 K, resulting in the following rate expression: k15 = (2.8 ± 0.7) × 10-13 exp[(515 ± 75)/T] cm3 molecule-1 s-1. Values of (2.0 ± 0.5) × 10-13, (1.5 ± 0.5) × 10-12, (9.0 ± 0.15) × 10-14, -12, (2.5 ± 0.5) × 10-12, and (8.2 ± 0.6) × 10-12 (units of cm3 molecule-1 s-1) have been obtained for the reactions of CH3O2 radicals with C2H5O2, neo-C5H11O2, c-C6H11O2, C6H5CH2O2, CH2ClO2, and CH3C(O)O2, respectively, and (1.0 ± 0.3) × 10-12, (5.6 ± 0.8) × 10-13, (4.0 ± 0.2) × 10-14, and (1.0 ± 0.3) × 10-11 (units of cm3 molecule-1 s-1) for the reactions of C2H5O2 with CH2=CHCH2O2, neo-C5H11O2, c-C6H11O2, and CH3C(O)O2 radicals, respectively. These rate constants were obtained by numerical simulations of the complete reaction mechanisms, which were deduced from the known mechanisms of the corresponding peroxy radical self-reactions. A systematic analysis of propagation of errors was carried out for each reaction to quantify the sensitivity of the cross-reaction rate constant to the parameters used in kinetic simulations. The rate constant for a given cross reaction is generally found to be between the rate constants for the self-reactions of RO2 and CH3O2 (or C2H5O2). However, when the RO2 self-reaction is fast, the cross reaction with CH3O2 (or C2H5O2) is also fast, with similar rate constants for both reactions, suggesting that these particular peroxy radical cross reactions can play a significant role in the chemistry of hydrocarbon oxidation processes in the troposphere and in low-temperature combustion. Relationships between cross-reaction and self-reaction rate constants are suggested.
