598-58-3Relevant articles and documents
Pressure dependence and kinetic isotope effects in the absolute rate constant for methoxy radical reacting with NO2
Chai, Jiajue,Dibble, Theodore S.
, p. 501 - 511 (2014)
We have investigated the kinetics for the reaction CH3O ? + NO2 in N2 bath gas. The rate constants are well-fit by the Troe expression over the temperature (250-335 K) and pressure range (30-700 Torr) investigated. The termolecular rate constant is given by k1a0=4.29-0.37 +0.40×10-29T/298-(1.65±1.11) cm6 molecule-2 s-1, and the rate constant at the high-pressure limit is given by k1a∞=(1. 95±0.03)×10-11T/298-(1.13±0.18) cm3 molecule-1 s-1. We also studied the kinetics of the reaction of CD3O? + NO2 as a function of temperature and pressure under similar conditions as those for CH3O? + NO2. The resulting low- and high-pressure limiting rate constants are k2a0=9.97-0.91 +1.00×10-29T/298-(4.79±0.92) cm6 molecule-2 s-1 and k2a ∞=(1.91±0.02)×10-11T/298 -(1.11±0.09) cm3 molecule-1 s -1, respectively. The rate constants for the two isotopologues track each other closely as the high-pressure limit is approached. The present results agree with most previous results at 295 K over a range of pressures, but there is substantial disagreement about the temperature dependence.
Role of methyl nitrate in plasma exhaust treatment
Hoard,Balmer,Wallington,Ball,Hurley,Wodzisz
, p. 3427 - 3431 (1999)
There is growing interest in the use of a nonthermal plasma combined with a catalyst for NOx removal from diesel engine exhaust streams, which contain excess oxygen (6-10%), low concentrations of hydrocarbons (100-1000 ppm), and significant concentrations of water (5-12%). Tests were performed to elucidate the effect of methyl nitrate (CH3ONO2) in the plasma-catalyst system since similar compounds have been proposed as reaction intermediates in NOx removal. NO, CO, CO2, O2, SO2, H2, Ar, C3H6, and C3H8 gases were mixed in N2 carrier. CH3ONO2 was prepared and added to the gas blend on test equipment simulating a diesel exhaust gas. CH3ONO2 was formed in a substantial yield on passing hydrocarbon/NOx/O2/N2 mixtures through a nonthermal plasma. The catalyst (consisted of two 24 mm x 24 mm long honeycombs) was very effective at removing CH3ONO2, which is converted into methanol and NO2. CH3ONO2 was not an important intermediate in the NOx removal reaction of the plasma-catalyst system.
Investigation into the Pressure Dependence between 1 and 10 Torr of the Reactions of NO2 with CH3 and CH3O
Biggs, Peter,Canosa-Mas, Carlos E.,Fracheboud, Jean-Marc,Parr, A. Douglas,Shallcross, Dudley E.,et al.
, p. 4163 - 4170 (1993)
The kinetic and pressure dependence of the reactions of NO2 with CH3 and CH3O have been investigated in the gas phase at 298 K, at pressure from 1 to 10 Torr.A low-pressure discharge-flow laser-induced fluorescence (LIF) technique was used.In a consecutive process, CH3 reacted with NO2 to form CH3O, CH3 + NO2 --> CH3O + NO (1), which further reacted with NO2 to form products, CH3O + NO2 --> products (2).Reaction (1) displayed no discernible pressure dependence over the pressure range 1-7 Torr, and k1 was calculated to be (2.3 +/- 0.3)E-11 cm3 molecule-1 s-1.Reaction (2) displayed a strong pressure dependence and an RRKM analysis yielded the following limiting low- and high-pressure rate constants in He, k0 = 5.9E-29 cm6 molecule-2 s-1 and k = 2.1E-11 cm3 molecule-1 s-1.It is unrealistic to quote errors for this type of analysis.Parametrisation in the standard Troe form with Fc = 0.6 yielded k0 = (5.3 +/-)E-29 cm6 molecule-2 s-1 and k = (1.4 +/- 0.1)E-11 cm3 molecule-1 s-1.Atmospheric implications and possible reaction mechanisms are discussed.
Fourier Transform Infrared Spectroscopic Study of the Thermal Stability of Peroxyacetyl Nitrate
Senum, G. I.,Fajer, R.,Gaffney, J. S.
, p. 152 - 156 (1986)
The unimolecular decomposition of peroxyacetyl nitrate (PAN) to form methyl nitrate and carbon dioxide has been studied over the temperature range 298-338 K by Fourier transform infrared spectroscopy (FTIR).Pure PAN samples (>98percent; 2-30 torr) were found to decompose thermally, nearly quantitatively, to these products, with the only other observed product being nitromethane (12)exp(-24.800+/-1800 cal/(K mol/RT)) s-1.Perdeuterio-PAN was synthesized and observed to decompose to perdeuteriomethyl nitrate and carbon dioxide with no apparent isotope effect.Experiments adding nitric oxide to the PAN are described which confirm the existence of two unimolecular pathways for the decomposition of peroxyacyl nitrates.One pathway is a concerted reaction most likely proceeding via a cyclic intermediate, and the other the previously identified equilibrium between PAN and the peroxyacetyl radical and nitrogen dioxide was determined to be 2.2*10-4 s-1 at 298 K.This rate is somewhat slower than previously reported for this pathway.The results are discussed with respect to the atmospheric liftime of PAN and the potential atmospheric production of methyl nitrate.
Reaction of CH2OH with O2, NO, and NO2 at Room Temperature
Pagsberg, Palle,Munk, Jette,Anastasi, Christopher,Simpson, Victoria J.
, p. 5162 - 5165 (1989)
The reaction of CH2OH with O2, NO, and NO2 has been studied using pulse radiolysis to generate the radicals and ultraviolet absorption to observe the kinetics.Rate constant values of (0.88 +/- 0.02) x 10-11, (2.5 +/- 0.02) x 10-11, and (2.3 +/- 0.4) x 10-11 cm3 molecule-1 s-1 have been measured at room temperature and 1 atm pressure for the O2, NO, and NO2 reactions, respectively.Absorptions due to long-lived or stable products were observed in the same spectral region.A simple analysis of these observations suggests that formation of an adduct may dominate in the reaction of CH2OH with NO and NO2 but that this process accounts for only a minor route in the O2 reaction.
Solid-State and Gas-Phase Structures and Energetic Properties of the Dangerous Methyl and Fluoromethyl Nitrates
Reichel, Marco,Krumm, Burkhard,Vishnevskiy, Yury V.,Blomeyer, Sebastian,Schwabedissen, Jan,Stammler, Hans-Georg,Karaghiosoff, Konstantin,Mitzel, Norbert W.
supporting information, p. 18557 - 18561 (2019/11/19)
An improved synthesis of the simplest nitric acid ester, methyl nitrate, and a new synthesis of fluoromethyl nitrate use the metathesis of the corresponding iodomethanes with silver nitrate. Both compounds were identified by spectroscopy and the structures determined for in situ grown crystals by X-ray diffraction as well as in the gas phase by electron diffraction. Fluorination leads to structures with shorter C?O and N?O bonds, has an energetically destabilizing effect and increases friction sensitivity, but decreases detonation performance.
Cold-surface photochemistry of selected organic nitrates
O'Sullivan, Daniel,McLaughlin, Ryan P.,Clemitshaw, Kevin C.,Sodeau, John R.
, p. 9890 - 9900 (2015/02/19)
Reflection-absorption infrared (RAIR) spectroscopy has been used to explore the low temperature condensed-phase photochemistry of atmospherically relevant organic nitrates for the first time. Three alkyl nitrates, methyl, isopropyl, and isobutyl nitrate together with a peroxyacyl nitrate, peroxyacetyl nitrate (PAN), were examined. For the alkyl nitrates, similar photolysis products were observed whether they were deposited neat to the gold substrate or codeposited with water. In addition to peaks associated with the formation of an aldehyde/ketone and NO, a peak near 2230 cm-1 was found to emerge in the RAIR spectra upon UV photolysis of the thin films. Together with evidence obtained by thermal programmed desorption (TPD), the peak is attributed to the formation of nitrous oxide, N2O, generated as a product during the photolysis. On the basis of the known gas-phase photochemistry for the alkyl nitrates, an intermediate pathway involving the formation of nitroxyl (HNO) is proposed to lead to the observed N2O photoproduct. For peroxyacetyl nitrate, CO2 was observed as a predominant product upon photolytic decomposition. In addition, RAIR absorptions attributable to the formation of methyl nitrate were also found to appear upon photolysis. By analogy to the known gas-phase and matrix-isolated-phase photochemistry of PAN, the formation of methyl nitrate is shown to likely result from the combination of alkoxy radicals and nitrogen dioxide generated inside the thin films during photolysis.
S-alkylation of thiacalixarenes: A long-neglected possibility in the calixarene family
Kundrat, Ondrej,Eigner, Vaclav,Dvorakova, Hana,Lhotak, Pavel
supporting information; scheme or table, p. 4032 - 4035 (2011/09/20)
Despite the high nucleophilicity of sulfur atoms, thiacalixarenes have been alkylated only on oxygen atoms thus far. Using strong alkylating agents (triflates, trialkyloxonium salts), the substitution of the sulfur bridges has been successfully accomplished. The corresponding sulfonium salts of thiacalix[4]arene are formed regio- and stereoselectively as a completely new type of substitution pattern in thiacalixarene chemistry. These compounds possess interesting conformational behavior and could be used as unusual alkylating agents with uncommon selectivity.
Vapor generation of inorganic anionic species after aqueous phase alkylation with trialkyloxonium tetrafluoroborates
D'Ulivo, Alessandro,Pagliano, Enea,Onor, Massimo,Pitzalis, Emanuela,Zamboni, Roberto
experimental part, p. 6399 - 6406 (2010/04/06)
Aqueous phase reaction of trialkyloxonium tetrafluoroborates, R 3O+BF4- (R=Me, Et) has been tested in the alkylation of simple inorganic anionic substrates such as halogen ions, cyanide, thiocyanate, sulphide an
The atmospheric oxidation of diethyl ether: Chemistry of the C 2H5-O-CH(O?)CH3 radical between 218 and 335 K
Orlando, John J.
, p. 4189 - 4199 (2008/09/19)
The products of the Cl atom initiated oxidation of diethyl ether (DEE) were investigated at atmospheric pressure over a range of temperatures (218-335 K) and O2 partial pressures (50-700 Torr), both in the presence and absence of NOx. The major products observed at 298 K and below were ethyl formate and ethyl acetate, which accounted for ≈60-80% of the reacted diethyl ether. In general, the yield of ethyl formate increased with increasing temperature, with decreasing O2 partial pressure, and upon addition of NO to the reaction mixtures. The product yield data show that thermal decomposition reaction (3), CH3CH2-O-CH(O ?)CH3 → CH3CH2-O-CH=O + CH3, and reaction (6) with O2, CH3CH 2-O-CH(O?)CH3 + O2 → CH3CH2-O-C(=O)CH3 + HO2 are competing fates of the CH3CH2-O-CH(O?) CH3 radical, with a best estimate of k3/k6 ≈ 6.9 × 1024 exp(-3130/T). Thermal decomposition via C-H or C-O bond cleavage are at most minor contributors to the CH3CH 2-O-CH(O?)CH3 chemistry. The data also show that the CH3CH2-O-CH(O?)CH 3 radical is subject to a chemical activation effect. When produced from the exothermic reaction of the CH3CH2-O-CH(OO ?)CH3 radical with NO, prompt decomposition via both CH3- and probably H-elimination occur, with yields of about 40% and ≤15%, respectively. Finally, at temperatures slightly above ambient, evidence for a change in mechanism in the absence of NOx, possibly due to chemistry involving the peroxy radical CH3CH2-O-CH(OO ?)CH3, is presented. the Owner Societies.
