- Reaction of the Nitrate Radical with Some Potential Automotive Fuel Additives. A Kinetic and Mechanistic Study
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Rate coefficients for the reaction of NO3 with ethyl tert-butyl ether (ETBE), diisopropyl ether (DIPE), and tert-amyl methyl ether (TAME) have been determined.Absolute rates were measured at temperatures between 257 and 367 K using the fast flow-discharge (FFD) technique.Relative rate experiments were also performed at 295 K in a reactor equipped with White optics and using FTIR spectroscopy to follow the reactions.Rate data from FFD experiments can be presented as follows: kETBE=(2.48 +/-0.78)E-12exp, kDIPE=(2.02 +/-0.35)E-12exp, and kTAME=(1.21 +/-0.22)E-12exp (in units of cm3 molecule-1 s-1).The rate coefficients at room temperature from the FFD experiments are in goog agreement with the corresponding rate coefficients from the relative experiments.Products from simulated atmospheric oxidation of the investigated ethers, initiated by the reaction with nitrate radical, were identified using FTIR spectroscopy.The degradation of ETBE results in tert-butyl formate, tert-butyl acetate, formaldehyde, and methyl nitrate, that of DIPE in acetone, isopropyl nitrate, isopropyl acetate, and formaldehyde, and that of TAME in tert-amyl formate, formaldehyde, and tert-amyl nitrate.
- Langer, Sarka,Ljundstroem, Evert
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p. 5906 - 5912
(2007/10/02)
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- Thermal Decomposition of Nitrate Esters
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Rates of thermal decomposition and solvent rate effects have been measured for a series of nitrate esters.The alkoxy radicals formed by homolysis together with some of their further degradation products have been stabilized by hydrogen donation.Internal and external return of nitrogen dioxide have been demonstrated by solvent cage effects and isotope exchange.Radical-stabilizing substituents favor β-scission.Dinitrates in a 1,5 relationship behave as isolated mononitrates.Dinitrates in a 1,3 or 1,4 relationship exhibit intramolecular reactions.Tertiary nitrate esters in diethyl ether undergo elimination rather than homolysis.
- Hiskey , Michael A.,Brower, Kay R.,Oxley, Jimmie C.
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p. 3955 - 3960
(2007/10/02)
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