OXIDATION OF N, N-DIMETHYLANILINE: II. THE REACTION WITH OXYGEN CATALYZED BY BENZOYL PEROXIDE

1963 ◽  
Vol 41 (12) ◽  
pp. 2945-2955 ◽  
Author(s):  
Donald M. Graham ◽  
Robert B. Mesrobian
Keyword(s):  
Hydrogen Peroxide ◽  
Benzoyl Peroxide ◽  
Rate Constants ◽  
Quantitative Yield ◽  
Chain Reaction ◽  
Polar Solvents ◽  
Oxidation Rates ◽  
Presence And Absence ◽  
A Chain

When benzoyl peroxide was used to initiate the reaction of oxygen with N,N-dimethylaniline, a chain reaction was shown to occur, resulting in an almost quantitative yield of hydrogen peroxide. The reaction was inhibited by mercaptan and benzoquinone, but not by hydroquinone, and was shown to be autoinhibited as well. The rate of oxidation was observed to be much greater in polar solvents, such as acetonitrile or methanol, than in non-polar solvents such as toluene and benzene. Diethyl- and dipropyl-aniline exhibited no chain characteristics under similar conditions, whereas dimethylbenzylamine and dimethyldodecylamine did not react at all.A mechanism has been postulated involving both semiquinone and peroxide chain carriers which is consistent with all of these observations. From an analysis of the oxidation rates in the presence and absence of mercaptan inhibition, the appropriate rate constants have been determined.

Absolute rate constants for hydrocarbon autoxidation. 33. A product study of the self-reaction of α-tetralylperoxyls in solution

1983 ◽  
Vol 61 (9) ◽  
pp. 2037-2043 ◽  
Author(s):  
A. Baignée ◽  
J. H. B. Chenier ◽  
J. A. Howard
Keyword(s):  
Steady State ◽  
Free Radical ◽  
Rate Constant ◽  
Rate Constants ◽  
The Self ◽  
Absolute Rate ◽  
Chain Reaction ◽  
Low Concentrations ◽  
A Chain ◽  
Product Study

The major initial products of the self-reaction of α-tetralylperoxyls (C10H11O2•) in chlorobenzene at 303–353 K are equal concentrations of α-tetralol and α-tetralone in ~90% yield based on the number of initiating radicals. These yields are consistent with the non-radical (Russell) mechanism for self-reaction. Low concentrations of bis(α-tetralyl) peroxide are produced, indicating that there is a small but detectable free-radical contribution towards termination. C10H11O2• undergoes β-scission in this temperature range but steady-state concentrations of C10H11• are too low to influence the termination rate constant 2kt, or react with C10H11O2• to give (C10H11O2. α-Tetralol to α-tetralone ratios and total yields of these products are significantly less than 1 and 100%, respectively, in methanol and acetonitrile. Formaldehyde is produced in methanol indicating the involvement of α-hydroxymethylperoxyls, derived from the solvent, in termination. There is no evidence for a chain reaction or a zwitterion intermediate for self-reaction of C10H11O2• in solution.

THE ACTION OF Co60 GAMMA RAYS AND OF FENTON'S REAGENT ON AQUEOUS BROMAL HYDRATE SOLUTIONS

1957 ◽  
Vol 35 (12) ◽  
pp. 1475-1486 ◽  
Author(s):  
R. J. Woods ◽  
J. W. T. Spinks
Keyword(s):  
Hydrogen Peroxide ◽  
Dose Rate ◽  
Gamma Rays ◽  
Hydrobromic Acid ◽  
Ferrous Sulphate ◽  
Fenton’S Reagent ◽  
Chain Reaction ◽  
Fenton's Reagent ◽  
A Chain ◽  
Co60 Gamma

Aqueous bromal hydrate solutions have been irradiated with Co60 gamma rays and the production of acid measured. The effect of bromal hydrate concentration, dose rate, pH, and temperature upon the yield of acid has been determined. Major products of the radiolysis have been identified and are compared with those formed when aqueous bromal hydrate solutions are treated with Fenton's reagent, a mixture of hydrogen peroxide and ferrous sulphate solutions. It has been shown that Fenton's reagent will initiate a chain reaction in aqueous bromal hydrate solutions which produces hydrobromic acid.

scholarly journals The combination of hydrogen and oxygen photosensitised by nitrogen peroxide

1933 ◽  
Vol 139 (837) ◽  
pp. 147-162 ◽  
Keyword(s):  
Hydrogen Peroxide ◽  
Spectroscopic Study ◽  
Gas Phase ◽  
Alternative Form ◽  
Chain Mechanism ◽  
Homogeneous Reaction ◽  
Chain Reaction ◽  
Chain Reactions ◽  
Temperature And Pressure ◽  
A Chain

The homogeneous reaction between hydrogen and oxygen has been proved by the work of Hinshelwood, of Haber, and of Semenoff to be a chain reaction, which under certain conditions of temperature and pressure may pass over into an explosive combination. The reaction is subject to the kinetics characteristic of certain types of chain reactions, in that, for any particular temperature, there are upper and lower pressure limits for explosion, the former controlled by deactivation of the chains in the gas phase, and the latter by their termination at the surface. The conditions further point to a branching chain mechanism; below 300°C. there is no observable propagation of reaction chains. These facts seem to be well represented by the scheme of Bonhoeffer and Haber, which was put forward on the basis of a spectroscopic study of the dissociation of steam at high temperatures. H + H 2 + O 2 = HO + H 2 O + 102,000 cals. (1) HO + H 2 = H 2 O + H + 10,000 cals. (2) reaction (1) sometimes taking the alternative form H + H 2 + O 2 = OH + OH + H - 2000 cals. (1a) which accounts for the branching of the chains. Reaction (2) does not occur appreciably at temperatures below 300°C., but the OH radicles yield hydrogen peroxide which may be detected.

The photosensitized polymerization of vinyl chloride in tetrahydrofuran solution - II. Theory of intermittent illumination for simultaneous monomer and mutual termination

1954 ◽  
Vol 221 (1144) ◽  
pp. 37-41 ◽  
Keyword(s):  
Light Intensity ◽  
Vinyl Chloride ◽  
Rate Constants ◽  
Chain Reaction ◽  
Rate Of Reaction ◽  
Intermittent Illumination ◽  
A Chain ◽  
Two Parameters ◽  
Tetrahydrofuran Solution

A theory of the effect of intermittent illumination for the general case of a chain reaction for which the overall rate of reaction is proportional to some power of the light intensity between 0⋅5 and unity is outlined. The relevant data for intermittent illumination of equal light and dark periods in terms of two parameters are tabulated. From such data the rate constants for the various steps of the chain reaction may be computed by methods which are indicated.

Observations on a Relationship between Steroid Metabolism and the Concentration of Plasma Fibrinogen

1963 ◽  
Vol 10 (02) ◽  
pp. 400-405 ◽  
Author(s):  
B. A Amundson ◽  
L. O Pilgeram
Keyword(s):  
Blood Coagulation ◽  
Methyl Ether ◽  
Broad Spectrum ◽  
Human Subjects ◽  
Plasma Fibrinogen ◽  
Steroid Metabolism ◽  
Specific Site ◽  
Chain Reaction ◽  
Normal Human ◽  
A Chain

SummaryEnovid (5 mg norethynodrel and 0.075 mg ethynylestradiol-3-methyl ether) therapy in young normal human subjects causes an increase in plasma fibrinogen of 32.4% (P >C 0.001). Consideration of this effect together with other effects of Enovid on the activity of specific blood coagulatory factors suggests that the steroids are exerting their effect at a specific site of the blood coagulation and/or fibrinolytic system. The broad spectrum of changes which are induced by the steroids may be attributed to a combination of a chain reaction and feed-back control.

scholarly journals Pathogenesis and Management of COVID-19

2021 ◽  
Vol 11 (2) ◽  
pp. 77-93
Author(s):  
Khalid O. Alfarouk ◽  
Sari T. S. AlHoufie ◽  
Samrein B. M. Ahmed ◽  
Mona Shabana ◽  
Ahmed Ahmed ◽  
...  
Keyword(s):  
Multiple Organ Failure ◽  
Human Body ◽  
Inflammatory Mediators ◽  
Expression Patterns ◽  
Multiple Organ ◽  
Cytokine Storm ◽  
Chain Reaction ◽  
Road Map ◽  
A Chain ◽  
Global War

COVID-19, occurring due to SARS-COV-2 infection, is the most recent pandemic disease that has led to three million deaths at the time of writing. A great deal of effort has been directed towards altering the virus trajectory and/or managing the interactions of the virus with its subsequent targets in the human body; these interactions can lead to a chain reaction-like state manifested by a cytokine storm and progress to multiple organ failure. During cytokine storms the ratio of pro-inflammatory to anti-inflammatory mediators is generally increased, which contributes to the instigation of hyper-inflammation and confers advantages to the virus. Because cytokine expression patterns fluctuate from one person to another and even within the same person from one time to another, we suggest a road map of COVID-19 management using an individual approach instead of focusing on the blockbuster process (one treatment for most people, if not all). Here, we highlight the biology of the virus, study the interaction between the virus and humans, and present potential pharmacological and non-pharmacological modulators that might contribute to the global war against SARS-COV-2. We suggest an algorithmic roadmap to manage COVID-19.

Sign in / Sign up

Export Citation Format

Share Document