The gas-phase reaction of methyl acetate and hydrogen bromide

1971 ◽  
Vol 24 (9) ◽  
pp. 1823
Author(s):  
NJ Daly ◽  
MF Gilligan
Keyword(s):  
Acetic Acid ◽  
Gas Phase ◽  
Kinetic Data ◽  
Methyl Acetate ◽  
Hydrogen Bromide ◽  
Mesityl Oxide ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
First Order ◽  
Order Form

In the gas phase methyl acetate reacts with hydrogen bromide over the range 419-497� to give methyl bromide, carbon monoxide, and methanol. Rate constants first order in both ester and hydrogen bromide are calculated from initial slopes, and are described by the equation �������������������� k2 = 1012.29exp(-32312/RT) ml mol-1 s-1 Kinetic data depart from this second-order form at early stages of the reaction. The addition of methanol can reduce the value of k2 to zero. A mechanism involving the reversible step : ������������������������ CH3COOCH3+HBr ↔ CH3OH+A* is proposed. The intermediate reacts with isobutene to form mesityl oxide, and is considered identical with that formed in the reaction of acetic acid with hydrogen bromide.

The gas-phase reaction of acetic acid with hydrogen bromide

1969 ◽  
Vol 22 (4) ◽  
pp. 713 ◽  
Author(s):  
NJ Daly ◽  
MF Gilligan
Keyword(s):  
Carbon Monoxide ◽  
Acetic Acid ◽  
Gas Phase ◽  
Rate Constant ◽  
Methyl Bromide ◽  
Hydrogen Bromide ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
First Order ◽  
The Family

In the gas phase, acetic acid reacts with hydrogen bromide in the temperature range 412-492� to give methyl bromide, carbon monoxide, and water. The reaction is first order in each reagent, and the variation of rate constant with temperature is described by the equation �� ����������������� k2 = 1011.67exp(-30400/RT) ml mole-1 sec-1 Possible transition states for the reaction are examined. A mechanism involving an intermediate of the type CH3CO+Br- is possible if the reaction is of the family represented by the hydrogen bromide catalysed decompositions of trimethylacetic, isobutyric, and propionic acids.

The gas-phase reaction of acetic acid with hydrogen bromide. The effect of isobutene

1971 ◽  
Vol 24 (4) ◽  
pp. 765 ◽  
Author(s):  
NJ Daly ◽  
MF Gilligan
Keyword(s):  
Acetic Acid ◽  
Gas Phase ◽  
Initial Rate ◽  
Hydrogen Bromide ◽  
Pressure Change ◽  
Mesityl Oxide ◽  
Phase Reaction ◽  
Thermal Reactions ◽  
Pressure Time ◽  
Molecular Reaction

Addition of isobutene to reaction mixtures of acetic acid and hydrogen bromide brings about a lowering in the initial rate of pressure change. The lowering is proportional to the pressure of isobutene and is explained in terms of a molecular reaction producing mesityl oxide. Mesityl oxide is formed steadily throughout the course of the reaction in quantities proportional to the pressure of isobutene. The quantities of mesityl oxide detected are less than those required to account quantitatively for the lowering of dp/dt, but the presence of the products of the thermal reactions of mesityl oxide, and the minima observed in the pressure-time curves at 407� show that the discrepancies can be accounted for in terms of the polymerization undergone by mesityl oxide in the presence of hydrogen bromide. The reaction appears analogous to the formation of mesityl oxide by the acetylation of isobutene in solution.

scholarly journals Rate coefficients for the gas-phase reaction of OH with <i>Z</i>-3-hexen-1-ol, 1-penten-3-ol, <i>E</i>-2-penten-1-ol, and <i>E</i>-2-hexen-1-ol between 243 and 404 K

2011 ◽  
Vol 11 (1) ◽  
pp. 2377-2405 ◽  
Author(s):  
M. E. Davis ◽  
J. B. Burkholder
Keyword(s):  
Gas Phase ◽  
Negative Temperature ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Oh Radical ◽  
Gas Phase Reaction ◽  
First Order ◽  
Unsaturated Alcohols ◽  
Temperature Dependences

Abstract. Rate coefficients, k, for the gas-phase reaction of the OH radical with (Z)-3-hexen-1-ol ((Z)-CH3CH2CH=CHCH2CH2OH). (k1), 1-penten-3-ol (CH3CH2CH(OH)CH=CH2) (k2), (E)-2-penten-1-ol ((E)-CH3CH2CH=CHCH2OH) (k3), and (E)-2-hexen-1-ol ((E)-CH3CH2CH2CH=CHCH2OH) (k4), unsaturated alcohols that are emitted into the atmosphere following vegetation wounding, are reported. Rate coefficients were measured under pseudo-first-order conditions in OH over the temperature range 243–404 K at pressures between 20 and 100 Torr (He) using pulsed laser photolysis (PLP) to produce OH radicals and laser induced fluorescence (LIF) to monitor the OH temporal profile. The obtained rate coefficients were independent of pressure with negative temperature dependences that are well described by the Arrhenius expressions k1(T) = (1.3 ± 0.1) × 10−11 exp[(580 ± 10)/T]; k1(297K) = (1.06 ± 0.12) × 10−10 k2(T) = (6.8 ± 0.7) × 10−12 exp[(690 ± 20)/T]; k2(297K) = (7.12 ± 0.73) × 10−11 k3(T) = (6.8 ± 0.8) × 10−12 exp[(680 ± 20)/T]; k3(297K) = (6.76 ± 0.70) × 10−11 k4(T) = (5.4 ± 0.6) × 10−12 exp[(690 ± 20)/T]; k4(297K) = (6.15 ± 0.75) × 10−11 (in units of cm3 molecule−1 s−1). The quoted uncertainties are at the 2σ (95% confidence) level and include estimated systematic errors. The rate coefficients obtained in this study are compared with literature values where possible.

The effect of inhibitors on the hydrogen-deuterium exchange reaction

1955 ◽  
Vol 232 (1189) ◽  
pp. 271-277 ◽  
Keyword(s):  
Nitric Oxide ◽  
Gas Phase ◽  
Exchange Reaction ◽  
Phase Reaction ◽  
Hydrogen Deuterium Exchange ◽  
Chain Reactions ◽  
Gas Phase Reaction ◽  
First Order ◽  
Hydrogen Deuterium ◽  
Hydrocarbon Pyrolysis

The exchange reaction between hydrogen and deuterium in silica vessels at temperatures in the region of 560° C has been studied, the rate of formation of HD being determined by massspectrometer analysis. Nitric oxide and propylene are effective inhibitors of the reaction: both reduce the rate to the same limit. The fully inhibited reaction is approximately of the first order, its activation energy is about 19000 kcal/g. mol. and in packed vessels the rate is roughly proportional to the ratio of surface to volume. This residual reaction, unlike that in hydrocarbon pyrolysis, seems therefore to be almost entirely heterogeneous, all gas-phase reaction having been suppressed. These results and their bearing on the use of nitric oxide and olefines for the inhibition of chain reactions are discussed.

Theoretical study of the gas phase reaction of methyl acetate with the hydroxyl radical: Structures, mechanisms, rates and temperature dependencies

2010 ◽  
Vol 490 (4-6) ◽  
pp. 116-122 ◽  
Author(s):  
Solvejg Jørgensen ◽  
Vibeke F. Andersen ◽  
Elna J.K. Nilsson ◽  
Ole John Nielsen ◽  
Matthew S. Johnson
Keyword(s):  
Hydroxyl Radical ◽  
Gas Phase ◽  
Methyl Acetate ◽  
Theoretical Study ◽  
Phase Reaction ◽  
Gas Phase Reaction

scholarly journals Rate coefficients for the gas-phase reaction of OH with (<i>Z</i>)-3-hexen-1-ol, 1-penten-3-ol, (<i>E</i>)-2-penten-1-ol, and (<i>E</i>)-2-hexen-1-ol between 243 and 404 K

2011 ◽  
Vol 11 (7) ◽  
pp. 3347-3358 ◽  
Author(s):  
M. E. Davis ◽  
J. B. Burkholder
Keyword(s):  
Gas Phase ◽  
Negative Temperature ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Oh Radical ◽  
Gas Phase Reaction ◽  
First Order ◽  
Unsaturated Alcohols ◽  
Temperature Dependences

Abstract. Rate coefficients, k, for the gas-phase reaction of the OH radical with (Z)-3-hexen-1-ol (Z)-CH3CH2CH = CHCH2CH2OH) (k1), 1-penten-3-ol (CH3CH2CH(OH)CH = CH2) (k2), (E)-2-penten-1-ol ((E)-CH3CH2CH = CHCH2OH) (k3), and (E)-2-hexen-1-ol ((E)-CH3CH2CH2CH = CHCH2OH) (k4), unsaturated alcohols that are emitted into the atmosphere following vegetation wounding, are reported. Rate coefficients were measured under pseudo-first-order conditions in OH over the temperature range 243–404 K at pressures between 20 and 100 Torr (He) using pulsed laser photolysis (PLP) to produce OH radicals and laser induced fluorescence (LIF) to monitor the OH temporal profile. The obtained rate coefficients were independent of pressure with negative temperature dependences that are well described by the Arrhenius expressions k1(T) = (1.3 ± 0.1) × 10−11 exp[(580 ± 10)/T]; k1(297 K) = (1.06 ± 0.12) × 10−10 k2(T) = (6.8 ± 0.7) × 10−12 exp[(690 ± 20)/T]; k2(297 K) = (7.12 ± 0.73) × 10−11 k3(T) = (6.8 ± 0.8) × 10−12 exp[(680 ± 20)/T]; k3(297 K) = (6.76 ± 0.70) × 10−11 k4(T) = (5.4 − 0.6) × 10−12 exp[(690 ± 20)/T]; k4(297 K) = (6.15 ± 0.75) × 10−11 (in units of cm3 molecule−1 s−1). The quoted uncertainties are at the 2σ (95% confidence) level and include estimated systematic errors. The rate coefficients obtained in this study are compared with literature values where possible.

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