THE PHOTOLYSIS OF ACETONE IN THE PRESENCE OF HYDROGEN BROMIDE

1955 ◽  
Vol 33 (2) ◽  
pp. 383-390 ◽  
Author(s):  
M. J. Ridge ◽  
E. W. R. Steacie
Keyword(s):  
Carbon Monoxide ◽  
Hydrogen Bromide ◽  
Methyl Radicals ◽  
Methyl Radical

The presence of hydrogen bromide during the photolysis of acetone sharply inhibits the yields of carbon monoxide, ethane, and volatile methyl radical derivatives as measured by the function (CH4 + 2C2H6). The observed effects can be explained on the assumption that both acetyl and methyl radicals react rapidly with HBr.

THE PHOTOLYSIS OF DEUTERATED ACETONE AND OF DEUTERATED ACETONE–HYDROGEN MIXTURES

1960 ◽  
Vol 38 (11) ◽  
pp. 2161-2170 ◽  
Author(s):  
J. F. Henderson ◽  
E. W. R. Steacie
Keyword(s):  
Carbon Monoxide ◽  
Excited Molecule ◽  
Methyl Radicals ◽  
Hydrogen Mixtures

The photolyses of acetone, acetone-d6, and acetone-d6 – hydrogen mixtures were investigated at 471 °K. The rates of formation of methane, ethane, and carbon monoxide and the ratio [Formula: see text] were independent of the fractional amount of acetone which photolyzed, as measured by 100[CO]/[A]0, which was varied from <1% to 18%. When the acetone-d6–hydrogen mixtures were photolyzed, [Formula: see text] and [Formula: see text] were observed to be functions of [A]0 and [H2]0. It is postulated that some of the CD4 and CD3H was formed by a reaction between methyl radicals and an excited molecule which contained both C—D and C—H bonds.

Addition of methyl radicals to carbon monoxide: Chemically and thermally activated decomposition of acetyl radicals

1974 ◽  
Vol 6 (6) ◽  
pp. 855-873 ◽  
Author(s):  
K. W. Watkins ◽  
William W. Word
Keyword(s):  
Carbon Monoxide ◽  
Methyl Radicals ◽  
Thermally Activated

Reactions of free radicals with aromatic compounds in the gaseous phase. I. Kinetics of the reaction of methyl radicals with toluene

1964 ◽  
Vol 17 (12) ◽  
pp. 1329 ◽  
Author(s):  
MFR Mulcahy ◽  
DJ Williams ◽  
JR Wilmshurst
Keyword(s):  
Flow System ◽  
Methyl Radicals ◽  
Methyl Radical ◽  
Hydrogen Atoms ◽  
Methyl Group ◽  
Benzyl Radical ◽  
Toluene Molecule ◽  
Benzyl Radicals ◽  
Butyl Peroxide ◽  
Kinetics Of

The kinetics of abstraction of hydrogen atoms from the methyl group of the toluene molecule by methyl radicals at 430-540�K have been determined. The methyl radicals were produced by pyrolysis of di-t-butyl peroxide in a stirred-flow system. The kinetics ,agree substantially with those obtained by previous authors using photolytic methods for generating the methyl radicals. At toluene and methyl-radical concentrations of about 5 x 10-7 and 10-11 mole cm-3 respectively the benzyl radicals resulting from the abstraction disappear almost entirely by combination with methyl radicals at the methylenic position. In this respect the benzyl radical behaves differently from the iso-electronic phenoxy radical, which previous work has shown to combine with a methyl radical mainly at ring positions. The investigation illustrates the application of stirred-flow technique to the study of the kinetics of free-radical reactions.

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.

The reaction of hydrogen atoms with ethylene

1970 ◽  
Vol 316 (1527) ◽  
pp. 575-591 ◽  
Keyword(s):  
Hydrogen Atom ◽  
Rate Constant ◽  
Recombination Reaction ◽  
Methyl Radicals ◽  
Methyl Radical ◽  
Hydrogen Atoms ◽  
Ethyl Radical ◽  
Cracking Reaction ◽  
Computer Calculations ◽  
First Time

A detailed study has been made of the products from the reaction between hydrogen atoms and ethylene in a discharge-flow system at 290 ± 3 K. Total pressures in the range 8 to 16 Torr (1100 to 2200 Nm -2 ) of argon were used and the hydrogen atom and ethylene flow rates were in the ranges 5 to 10 and 0 to 20 μ mol s -1 , respectively. In agreement with previous work, the main products are methane and ethane ( ~ 95%) together with small amounts of propane and n -butane, measurements of which are reported for the first time. A detailed mechanism leading to formation of all the products is proposed. It is shown that the predominant source of ethane is the recombination of two methyl radicals, the rate of recombination of a hydrogen atom with an ethyl radical being negligible in comparison with the alternative, cracking reaction which produces two methyl radicals. A set of rate constants for the elementary steps in this mechanism has been derived with the aid of computer calculations, which gives an excellent fit with the experimental results. In this set, the values of the rate constant for the addition of a hydrogen atom to ethylene are at the low end of the range of previously measured values but are shown to lead to a more reasonable value for the rate constant of the cracking reaction of a hydrogen atom with an ethyl radical. It is shown that the recombination reaction of a hydrogen atom with a methyl radical, the source of methane, is close to its third-order region.

Theoretical Study of the Kinetics and Mechanism of the Thermal Decomposition of 3-Oxetanone in the Gas Phase

2017 ◽  
Vol 42 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Mohammad Khavani ◽  
Javad Karimi
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Ethylene Oxide ◽  
Gas Phase ◽  
Transition States ◽  
Decomposition Reaction ◽  
Kinetics And Mechanism ◽  
Methyl Radical ◽  
Decomposition Products ◽  
Concerted Mechanism

The kinetics and mechanism of the thermal decomposition reaction of 3-oxetanone in the gas phase were studied using quantum chemical calculations. The major products of this reaction are formaldehyde, ketene, carbon monoxide, ethylene oxide, ethylene and methyl radical. Formaldehyde, ketene, carbon monoxide and ethylene oxide are the initial decomposition products and other species are the products of ethylene oxide decomposition. The results of B3LYP and QCISD(T) calculations reveal that thermal decomposition of 3-oxetanone to ethylene oxide and carbon monoxide is more probable than to formaldehyde and ketene from an energy viewpoint. Moreover, quantum theory of atoms in molecules and natural bond orbital analysis indicate that 3-oxetanone decomposition to formaldehyde, ketene, carbon monoxide and ethylene occurs via a concerted mechanism and bonds that are involved in the transition states have a covalent character. Moreover, the calculated changes in bond lengths in the transition states reveal that bond breaking and new bond formation occur asynchronously in a concerted mechanism.

Thermal reactions of mesityl oxide

1971 ◽  
Vol 24 (5) ◽  
pp. 955 ◽  
Author(s):  
NJ Daly ◽  
MF Gilligan
Keyword(s):  
Carbon Monoxide ◽  
Methyl Bromide ◽  
Hydrogen Bromide ◽  
The Other ◽  
Mesityl Oxide ◽  
Thermal Reactions ◽  
First Order ◽  
First Order Kinetics

Mesityl oxide (4-methylpent-3-en-2-one) thermally decomposes in the range 412-490� give methylbutenes, carbon monoxide, isobutene, and methane as major products. The initial 20% of reaction follows first- order kinetics and is described by the equation k1 = 1014.22exp(-63240/RT) s-1. A Rice-Herzfeld chain is proposed. Addition of hydrogen bromide leads to two reactions, one producing isobutene, carbon monoxide, and methyl bromide, and the other leading to polymerization. Likely steps in the polymerization are proposed.

Theoretical study on the methyl radical with chlorinated methyl radicals CH3−nCln (n = 1, 2, 3) and CCl2

2007 ◽  
Vol 28 (5) ◽  
pp. 865-876 ◽  
Author(s):  
Jian Wang ◽  
Yi-Hong Ding ◽  
Shao-Wen Zhang ◽  
Chia-Chung Sun
Keyword(s):  
Theoretical Study ◽  
Methyl Radicals ◽  
Methyl Radical

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.

scholarly journals Microwave spectrum and molecular structure of the carbon monoxide-hydrogen bromide molecular complex

1980 ◽  
Vol 77 (10) ◽  
pp. 5583-5587 ◽  
Author(s):  
M. R. Keenan ◽  
T. K. Minton ◽  
A. C. Legon ◽  
T. J. Balle ◽  
W. H. Flygare
Keyword(s):  
Molecular Structure ◽  
Carbon Monoxide ◽  
Molecular Complex ◽  
Hydrogen Bromide ◽  
Microwave Spectrum
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