scholarly journals The kinetics of the oxidation of mixtures of ethylene and acetaldehyde

1934 ◽  
Vol 146 (856) ◽  
pp. 72-82 ◽  
Keyword(s):  
Organic Compounds ◽  
Practical Importance ◽  
Initial Step ◽  
Chain Reactions ◽  
Oxidation Of Organic Compounds ◽  
Real Relation ◽  
Gaseous Hydrocarbons ◽  
A Chain ◽  
Hydroxyl Compounds ◽  
Kinetics Of

The oxidation of gaseous hydrocarbons has long attracted considerable interest on account pf its theoretical and practical importance. Early work was concerned entirely with the identification of the products of oxidation, and the postulation of plausible intermediate steps in their formation. As a result of such work Bone and his collaborators suggested the so-called "hydroxylation theory", which involved the orderly formation of hydroxyl compounds during oxidation, and their subsequent decomposition of further oxidation. This theory gives an excellent explanation of the intermediate and final products formed in the oxidation of most simple hydrocarbons. As far as the mechanism of the actual oxidation process is concerned, little progress was made until the development of the idea of thermal chain reactions. It is now generally conceded that the oxidation of most gaseous organic compounds proceeds by a chain mechanism. The main problem at the present time is to obtain some definite information regarding the carriers of the chains. One of the most useful attempts in this direction is the peroxide theory of Egerton, in which it is assumed that the initial step in the oxidation of organic compounds is the formation of an energy-rich complex with oxygen, which is called a "peroxide". Whether such a complex bears any real relation to actual stable alkyl peroxides is quite unknown.

scholarly journals The influence of foreign gases on the lower critical oxidation pressure of carbon disulphide

1932 ◽  
Vol 137 (833) ◽  
pp. 511-519 ◽  
Keyword(s):  
Carbon Disulphide ◽  
Chemical Change ◽  
Energy Of Activation ◽  
Unimolecular Reaction ◽  
Total Change ◽  
Chain Reactions ◽  
A Chain ◽  
Kinetics Of

The study of gaseous reactions has recently acquired additional interest, since it has been found that a considerable number of reactions can be explained on the basis of a chain hypothesis. In 1923 Christiansen and Kramers studied the kinetics of a unimolecular reaction and found that explosion is possible if the total change of energy resulting from the reaction is greater than the energy of activation. Since that time the mechanism of chain reactions has been carefully investigated and some of the conditions for the continued propagation of the reaction have been ascertained. Thus, if we have two gases mixed together without any chemical change taking place, a reaction may commence when even a very small quantity of a third molecule is added, or if one of the original molecules receives energy of activation (from whatever cause). Designating the original molecules for simplicity by A and B and the new molecule by C, which we will suppose reacts with A, giving a fourth molecule D (and possibly other molecules also), we have A + C → D.

scholarly journals Further investigations on the kinetics of gaseous oxidation reactions

1930 ◽  
Vol 129 (810) ◽  
pp. 284-299 ◽  
Keyword(s):  
Rate Of Change ◽  
Chain Mechanism ◽  
Oxidation Reactions ◽  
Chain Reactions ◽  
Oxidation Of Methane ◽  
Simple Order ◽  
Oxidation Of Hydrocarbons ◽  
Rate Of Reaction ◽  
A Chain ◽  
Kinetics Of

Investigation of the kinetics of the oxidation of ethylene and of benzene showed that these reactions are peculiar in the following respects. First, the relation between the rate of reaction and concentration is such that the reactions possess no simple “order,” though the nearest integral value for the order is about the third of fourth. The rate increases very rapidly with increasing hydrocarbon concentration, but is relatively little influenced by oxygen; under some conditions oxygen may have a retarding influence. Secondly, the reactions can be slowed down by increasing the surface exposed to the gases. This indicates that the oxidation occurs by a chain mechanism. Thirdly, the rate of change of pressure accompanying the oxidation only attains its full value after an induction period, during which evidently intermediate products are accumulating. Accepting the fact that the oxidations are probably chain reactions, the relation between rate and concentration shown that the chains are much more easily propagated when the intermediate active molecules encounter more hydrocarbon than when they encounter oxygen. Following the view of Egerton, and consistently with previous work on the combination of hydrogen and oxygen, the working hypothesis adopted is that some intermediate peroxidised substance is responsible for the propagation of the chains. This being so, the question arises whether the peculiarities found in the oxidation of hydrocarbons will also be found with substances already containing oxygen. To investigate, therefore, the influence of chemical configuration on the mechanism of oxidation reactions the following series of compounds has been studied CH 4 CH 3 OH HCHO which represent the stages through which Bone and others have shown the oxidation of methane to occur.

2, 4-Ionene Supported Permanganate: A Novel, Efficient and Selective Solid Phase Oxidizing Agent for Oxidation of Organic Compounds

2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Moslem Mansour Lakouraj ◽  
Sayed Maysam Hossaini ◽  
Vahid Hasantabar ◽  
Masoomeh Soleimani
Keyword(s):  
Aqueous Solution ◽  
Organic Compounds ◽  
Carbonyl Compounds ◽  
Room Temperature ◽  
Solid Phase ◽  
Oxidizing Agent ◽  
Solvent Free Conditions ◽  
Oxidation Of Organic Compounds ◽  
Different Types ◽  
Hydroxyl Compounds

Abstract2, 4-ionene supported permanganate is easily prepared by treatment of 2, 4-ionene with an aqueous solution of potassium permanganate. This reagent could be used as a stable, mild and efficient oxidizing agent to produce carbonyl compounds from hydroxyl compounds or arenes, and disulfides from thiols in either heterogonous or solvent free conditions. In addition, aromatization of different types of 2-arylimidazolines and 2-alkylimidazolines to corresponding imidazoles was achieved in good yields in acetonitrile at room temperature.

scholarly journals Direct observation and kinetics of a hydroperoxyalkyl radical (QOOH)

Science ◽  
2015 ◽  
Vol 347 (6222) ◽  
pp. 643-646 ◽  
Author(s):  
John D. Savee ◽  
Ewa Papajak ◽  
Brandon Rotavera ◽  
Haifeng Huang ◽  
Arkke J. Eskola ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Direct Observation ◽  
Organic Aerosol ◽  
Organic Radicals ◽  
Radical Chain ◽  
Radical Intermediates ◽  
Oxidation Of Organic Compounds ◽  
Resonance Stabilization ◽  
Kinetics Of ◽  
Insight Into

Oxidation of organic compounds in combustion and in Earth’s troposphere is mediated by reactive species formed by the addition of molecular oxygen (O2) to organic radicals. Among the most crucial and elusive of these intermediates are hydroperoxyalkyl radicals, often denoted “QOOH.” These species and their reactions with O2 are responsible for the radical chain branching that sustains autoignition and are implicated in tropospheric autoxidation that can form low-volatility, highly oxygenated organic aerosol precursors. We report direct observation and kinetics measurements of a QOOH intermediate in the oxidation of 1,3-cycloheptadiene, a molecule that offers insight into both resonance-stabilized and nonstabilized radical intermediates. The results establish that resonance stabilization dramatically changes QOOH reactivity and, hence, that oxidation of unsaturated organics can produce exceptionally long-lived QOOH intermediates.

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