Catalysis by hydrogen halides in the gas phase. XXIV. 2,2-Dimethoxypropane and hydrogen chloride

1972 ◽  
Vol 25 (4) ◽  
pp. 793 ◽  
Author(s):  
VR Stimson ◽  
JW Tilley
Keyword(s):  
Gas Phase ◽  
Hydrogen Chloride ◽  
Radical Chain ◽  
Hydrogen Halides ◽  
First Order

The decomposition of 2,2-dimethoxypropane to methyl isopropenyl ether and methanol in the gas phase is catalysed by hydrogen chloride in c. 1% proportion at 226-364�C. The reaction is first order in each reactant and rates are given by the equation kz = 2.3 x 1013 exp(-22200/RT) (s-1 ml mol-1) The possibility of the reaction being a radical chain or surface one is discussed. However, it is believed to be homogeneous and molecular.

Catalysis by hydrogen halides in the gas phase. XVIII. Methyl formate and hydrogen bromide

1968 ◽  
Vol 21 (7) ◽  
pp. 1711
Author(s):  
DA Kairaitis ◽  
VR Stimson
Keyword(s):  
Carbon Monoxide ◽  
Gas Phase ◽  
Decomposition Product ◽  
Methyl Formate ◽  
Arrhenius Equation ◽  
Hydrogen Bromide ◽  
Radical Chain ◽  
Hydrogen Halides ◽  
Chain Decomposition ◽  
First Order

Hydrogen bromide catalyses the decomposition of methyl formate into carbon monoxide and methanol at 390-460�. The radical chain decomposition product, methane, is formed in only a small amount that is further reduced by the addition of inhibitor. The reaction is homogeneous and molecular, is first order in each reactant, and follows the Arrhenius equation: k2 = 1012.50exp(-32200/RT)sec-1 ml mole-1 It is not reversed by added methanol.

Catalysis by hydrogen halides in the gas phase. XI. Tertiary butyl ethyl ether and hydrogen chloride

1966 ◽  
Vol 19 (3) ◽  
pp. 401 ◽  
Author(s):  
VR Stimson ◽  
EJ Watson
Keyword(s):  
Gas Phase ◽  
Hydrogen Chloride ◽  
Ethyl Ether ◽  
Arrhenius Equation ◽  
Hydrogen Halide ◽  
Hydrogen Halides ◽  
Tertiary Butyl ◽  
First Order ◽  
Mechanism Of The Reaction ◽  
Kinetic Form

Hydrogen chloride catalyses the decomposition of t-butyl ethyl ether at 320-428�. Isobutene is quantitatively the product and the kinetic form is first order in the ether and in hydrogen chloride. The Arrhenius equation:��������� k, = 1012'16exp( -30,60O/RT) (sec-l ml mole-=) is followed. The mechanism of the reaction seems similar to those of other hydrogen halide catalysed decompositions of ethers and alcohols.

Catalysis by hydrogen halides in the gas phase. IX. Tertiary butyl ether and hydrogen bromide

1966 ◽  
Vol 19 (1) ◽  
pp. 75 ◽  
Author(s):  
VR Stimson ◽  
EJ Watson
Keyword(s):  
Gas Phase ◽  
Hydrogen Bromide ◽  
Zero Order ◽  
Chain Reaction ◽  
Butyl Ether ◽  
Radical Chain ◽  
Hydrogen Halides ◽  
Tertiary Butyl ◽  
First Order ◽  
Radical Chain Reaction

The hydrogen bromide catalysed decomposition of t-butyl ethyl ether takes place at 263-337�. Two major reactions occur, one producing isobutene by kinetics first order in each reactant, and the other isobutane by kinetics first order in the ether and zero order in hydrogen bromide. The latter is extensively inhibited by cyclohexene and is a radical chain reaction; the former is not inhibited and is presumably molecular, and on this basis its properties form a smooth sequence with those of other similar hydrogen halide catalysed decompositions.

Catalysis by hydrogen halides in the gas phase. X. Tertiary butyl methyl ether and hydrogen chloride

1966 ◽  
Vol 19 (3) ◽  
pp. 393 ◽  
Author(s):  
VR Stimson ◽  
EJ Watson
Keyword(s):  
Gas Phase ◽  
Surface Area ◽  
Hydrogen Chloride ◽  
Methyl Ether ◽  
Rate Equation ◽  
Hydrogen Halides ◽  
Tertiary Butyl ◽  
First Order ◽  
Tertiary Butyl Methyl Ether ◽  
Butyl Methyl Ether

The decomposition of t-butyl methyl ether catalysed by hydrogen chloride takes place at 337-428�. It is first order in each reactant and the rate is not affected by increase in surface area or inhibitor. The rate equation is: K2 = 1012.46exp(-32100/RT) (sec-l ml mole-l) The reaction is believed to be molecular and its properties are in accord with those of other such catalysed decompositions.

Catalysis by hydrogen halides in the gas phase. XIX. 2,3-Dimethylbutan-2-ol and hydrogen bromide

1968 ◽  
Vol 21 (10) ◽  
pp. 2385 ◽  
Author(s):  
RL Johnson ◽  
VR Stimson
Keyword(s):  
Gas Phase ◽  
Arrhenius Equation ◽  
Hydrogen Bromide ◽  
Phase Decomposition ◽  
Hydrogen Halides ◽  
First Order

The gas-phase decomposition of 2,3-dimethylbutan-2-ol into 2,3-dimethylbut-1-ene, 2,3-dimethylbut-2-ene, and water, catalysed by hydrogen bromide at 303-400�, is described. The rate is first-order in each reactant and the Arrhenius equation k2 = 1011.88 exp(-26490/RT) sec-l ml mole-1 is followed. The olefins appear to be in their equilibrium proportions. The effects of substitutions in the alcohol at Cα and Cβ on the rate are discussed.

Catalysis by hydrogen halides in the gas phase. XIV. Methyl trimethylacetate and hydrogen bromide and the effects of added alcohols

1968 ◽  
Vol 21 (3) ◽  
pp. 687 ◽  
Author(s):  
JTD Cross ◽  
VR Stimson
Keyword(s):  
Carbon Monoxide ◽  
Methyl Ester ◽  
Gas Phase ◽  
Hydrogen Chloride ◽  
Hydrogen Bromide ◽  
Hydrogen Halides ◽  
Kinetic Form

Hydrogen bromide and hydrogen chloride catalyse the decomposition of methyl trimethylacetate into isobutene, carbon monoxide, and methanol at 370-442� and 450-48O�, respectively. The kinetic form, which is basically 1 : 1, is severely modified by the effect of methanol either produced in the reaction or added initially. Water or alcohols react with an intermediate in the catalysed decomposition of trimethylacetic acid or its methyl ester in esterification-like reactions; some of the resultant esters subsequently decompose to olefin and acid.

Catalysis by hydrogen halides in the gas phase. XXIII. 1,1-Dimethoxyethane and hydrogen bromide

1971 ◽  
Vol 24 (5) ◽  
pp. 961 ◽  
Author(s):  
VR Stimson
Keyword(s):  
Gas Phase ◽  
Vinyl Ether ◽  
Arrhenius Equation ◽  
Hydrogen Bromide ◽  
Phase Decomposition ◽  
Hydrogen Halides ◽  
Methyl Vinyl ◽  
First Order ◽  
Methyl Vinyl Ether

Hydrogen bromide catalyses the gas-phase decomposition of 1,1- dimethoxy-ethane at 233-322� into methyl vinyl ether and methanol. The reaction, first-order in each reactant, is believed to be homogeneous and molecular. ��� The Arrhenius equation ������ �����������k2 = 1.3x1013exp(-22160/RT) s-1 cm3 mol-1 is followed. This decomposition is much faster than the analogous reactions of alcohols and ethers. The catalyst is effective when present in only 1% proportion.

The thermal decompositions of 2-methyl-2-phenoxypropane

1981 ◽  
Vol 34 (2) ◽  
pp. 343 ◽  
Author(s):  
NJ Daly ◽  
SA Robertson ◽  
LP Steele
Keyword(s):  
Gas Phase ◽  
Reaction Mechanisms ◽  
Arrhenius Equation ◽  
Chain Process ◽  
Quadrupole Mass ◽  
Radical Chain ◽  
Thermal Reactions ◽  
First Order ◽  
Radical Chain Process ◽  
Good Agreement

The thermal reactions of 2-methyl-2-phenoxypropane have been studied in gas phase over the range 600-670 K by quadrupole mass spectrometry and pressure studies. The reaction is shown to be a homogeneous first-order elimination of phenol and 2-methylpropene which is described by the Arrhenius equation k = 1014.10�0.12exp[(-210.46�1.36)/RT] s-1 Possible reaction mechanisms are considered and the reaction is found to be a unimolecular elimination rather than a radical chain process initiated by homolysis to phenoxy and 1,1-dimethylethyl radicals. Evidence for the rearrangement to 4-t-butylphenol previously proposed has been carefully sought and it is concluded that the process does not occur in the gas phase. The A-factor observed for the reaction is in good agreement with that calculated for the four-centred transition state proposed for elimination of 2-methylpropene from alkoxypropanes.

The kinetics of the pyrolysis of Cyclohexyl chloride.

1958 ◽  
Vol 11 (3) ◽  
pp. 314 ◽  
Author(s):  
ES Swinbourne
Keyword(s):  
Gas Phase ◽  
Hydrogen Chloride ◽  
Rate Coefficient ◽  
Initial Pressure ◽  
Order Reaction ◽  
Rate Coefficients ◽  
Homogeneous Reaction ◽  
First Order ◽  
Induction Periods ◽  
Kinetics Of

cycloHexy1 chloride has been shown to decompose in the gas phase at 318-385 �C almost exclusively to cyclohexene and hydrogen chloride. With clean glass-walled reactors the reaction was largely heterogeneous, but after the walls were coated with a carbonaceous film a homogeneous first-order reaction was found to predominate. For initial pressures within the range 4-40 cm mercury the rate coefficients for the homogeneous reaction were expressible as������� k = 5.88 x 1013exp(-50,000 cal/RT) sec-1. There was some evidence for the rate coefficient becoming pressure-dependent below 5-10 mm initial pressure of reactant. The reaction exhibited no induction periods and the velocity was virtually unaffected by the addition of large amounts of propene or cyclohexene and traces of chlorine or bromine. The results were consistent with a unimolecular elimination of hydrogen chloride.

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