Radiation-induced oxidation of 2-propanol by hydrogen peroxide in aqueous solutions

1970 ◽  
Vol 48 (8) ◽  
pp. 1232-1238 ◽  
Author(s):  
C. E. Burchill ◽  
I. S. Ginns
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Lower Limit ◽  
Alcohol Concentration ◽  
Chain Mechanism ◽  
Radiation Induced ◽  
A Chain ◽  
High Yields ◽  
Radical Conversion

The radiation-induced oxidation of 2-propanol by hydrogen peroxide in neutral deaerated aqueous solution has been investigated. 2-Propanol is oxidized to acetone, and hydrogen peroxide reduced in stoichiometrically equivalent high yields. The yields are independent of hydrogen peroxide concentration in the range 5 × 10−2 to 10−3 M and linearly dependent on alcohol concentration in the range 0.13 to 1.05 M. The reaction yields increased with decreasing dose rate.The results are explained by a chain mechanism in which initiation occurs via H-atom abstraction from 2-propanol to form either (CH3)2ĊOH (1) or CH3 CHOH ĊH2 (2). 1 reacts with H2O2 in a chain propagating reaction[Formula: see text]2 may abstract the α hydrogen from the parent alcohol[Formula: see text]or undergo bimolecular termination. A lower limit of 53 ± 101mole−1 s−1 is estimated for the rate constant for this radical conversion reaction.

Radiation-induced Rearrangement of Ethylene Glycol in Aqueous Solution

1971 ◽  
Vol 49 (14) ◽  
pp. 2382-2389 ◽  
Author(s):  
C. E. Burchill ◽  
K. M. Perron
Keyword(s):  
Hydrogen Peroxide ◽  
Ethylene Glycol ◽  
Aqueous Solutions ◽  
Transfer Reaction ◽  
Major Product ◽  
Hydrogen Atom Transfer ◽  
Γ Irradiation ◽  
Radical Chain ◽  
Radiation Induced ◽  
A Chain

Under γ-irradiation, aqueous solutions of ethylene glycol containing hydrogen peroxide form acetaldehyde as a major product via a free-radical chain rearrangement. The yield of acetaldehyde is essentially unchanged when hydrogen peroxide is replaced by N2O or HClO4. A mechanism is proposed in which the glycol radical, ĊOHCH2OH, rearranges to the acetaldehyde precursor, ĊH2CHO, followed by the hydrogen atom transfer reaction;[Formula: see text]thus propagating a chain reaction.2The rearrangement is also induced by the photo-dissociation of H2O2 in aqueous solutions of ethylene glycol.

Radiation-induced oxidation of 2-propanol by hydrogen peroxide in aqueous solutions

1970 ◽  
Vol 48 (18) ◽  
pp. 2948-2948
Author(s):  
C. E. Burchill ◽  
I. S. Ginns
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Radiation Induced

not available

Studies of radiation-induced reactions of ethylene in aqueous solution II. Reactions in the presence of oxygen as studied by pulse radiolysis and γ -irradiation techniques

1967 ◽  
Vol 300 (1463) ◽  
pp. 443-454 ◽  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Major Product ◽  
Peroxy Radicals ◽  
Ferrous Ions ◽  
Constant Composition ◽  
Γ Irradiation ◽  
Radiation Induced

The radiolysis of dilute aqueous solutions containing ethylene and oxygen has been investigated. Pulse radiolysis was used to measure the rate constants for the addition of hydroxyl radicals to ethylene, the binary decomposition of the resulting hydroxyethyl radicals and their addition to ethylene and reaction with oxygen to yield peroxy radicals. The rate constants have also been determined for the mutual interaction of the peroxy radicals and their reaction with ferrous ions. The principal products of γ -irradiation were aldehydes and organic hydroperoxides. Hydrogen peroxide was found in yields close to the molecular yield from water. The polymer produced in the absence of oxygen was not formed, and glycollaldehyde, reported as a major product by previous workers, could not be detected. At constant composition of the gas mixtures, product yields were unaffected by total pressure in the range up to 40 atm, but were strongly dependent on the proportion of oxygen. Aldehyde yields were markedly greater at pH 1.2 than in neutral solution. The influence of ferrous ions an d of added hydrogen peroxide has been determined. The pulse radiolysis and γ -irradiation experiments complement one another and show that the radiation-induced oxidation of ethylene in aqueous solution involves the same primary reactions as occur in the absence of oxygen, followed by the formation and further reactions of peroxy radicals.

The gaseous oxidation of aliphatic alcohols. III. n - and iso -propyl alcohols

1960 ◽  
Vol 257 (1290) ◽  
pp. 402-412 ◽  
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Monoxide ◽  
Free Radicals ◽  
Induction Period ◽  
Isopropyl Alcohol ◽  
Side Reactions ◽  
Chain Mechanism ◽  
Complete Elimination ◽  
Chain Branching ◽  
A Chain

A study of the gaseous oxidation of n -propyl alcohol (1-propanol) at 264°C shows that, after an induction period during which higher aldehydes and hydrogen peroxide are apparently the only products formed, the pressure starts to rise autocatalytically and methanol, formaldehyde and carbon monoxide become detectable. Additions of higher aldehydes reduce the induction period but the amounts required for its complete elimination are considerably greater than those normally present at the end of the induction period. A chain mechanism is proposed which involves initially abstraction of hydrogen from 1-propanol by HO 2 radicals followed by interaction of the resulting hydroxypropyl radicals with oxygen to yield propionaldehyde. Further reactions of this aldehyde are believed to be responsible for chain-branching and for the formation of the various C 1 products. Isopropyl alcohol (2-propanol) is much less readily oxidized than 1-propanol. At 330°C the main oxidation product is acetone which is formed together with hydrogen peroxide in somewhat smaller quantities. Minor products include methanol, acetaldehyde and formaldehyde. The course of the oxidation of 2-propanol is little affected by additions of acetone or formaldehyde but the induction period is markedly reduced by added acetaldehyde. The chain cycle suggested for the initial stages of oxidation involves attack by HO 2 radicals at the tertiary C─H bond of the alcohol followed by reaction of the resulting free radicals with oxygen to give acetone. The intermediate responsible for chain-branching is believed to be acetaldehyde which is produced by side reactions. C 1 compounds are formed partly by oxidation of this aldehyde and partly by further reactions of acetone.

Radiation-induced Oxidation of 2-Propanol by Nitrous Oxide in Alkaline Aqueous Solution

1972 ◽  
Vol 50 (11) ◽  
pp. 1751-1756 ◽  
Author(s):  
C. E. Burchill ◽  
G. P. Wollner
Keyword(s):  
Aqueous Solution ◽  
Rate Constant ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Chain Mechanism ◽  
Radical Chain ◽  
Kinetic Isotope ◽  
Alkaline Aqueous Solution ◽  
Radiation Induced ◽  
Solution Proceeds

The radiation-induced oxidation of 2-propanol to acetone by N2O in alkaline aqueous solution proceeds via a free radical chain mechanism independent of pH above 12.5. The results are explained by abstraction of H from 2-propanol by O− at both the α and β positions (85% α attack). Chain propagation is by reaction of the α radical anion, (CH3)2ĊO−, with N2O with a rate constant of (3.8 ± 0.4) × 104 M−1 s−1 and by reaction of the β radical, ĊH2(CH3)CHOH, with 2-propanol to give the α radical with a rate constant of 430 ± 30 M−1 s−1.The conclusions are supported by the demonstration of kinetic isotope effects for selectively deuterated alcohols.

scholarly journals Transition Metal-free Epoxidation of Alkenes Based on the Existence of (2- hydroxypropyl)-β-CD

2015 ◽  
Vol 9 (1) ◽  
pp. 20-24
Author(s):  
Shi Dongpo ◽  
Yin Xianqing ◽  
Zheng Yancheng ◽  
Chen wu ◽  
Fu Jiaxin ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Transition Metal ◽  
Sodium Bicarbonate ◽  
Ambient Temperature ◽  
Metal Free ◽  
High Yields ◽  
Epoxidation Of Alkenes

A green, efficient epoxidation of alkenes with hydrogen peroxide (HO) and sodium bicarbonate (NaHCO3) catalyzed by (2-hydroxypropyl)-β-cyclodextrin (2-hp-β-CD) in aqueous solution has been investigated in detail. A range of alkenes were epoxidized at ambient temperature with high yields.

Free-Radical Reductions of Arenediazonium Ions in Aqueous Solution. VI. On Iododediazoniation

1985 ◽  
Vol 38 (6) ◽  
pp. 991 ◽  
Author(s):  
JE Packer ◽  
RER Taylor
Keyword(s):  
Aqueous Solution ◽  
Free Radical ◽  
Aqueous Solutions ◽  
Major Product ◽  
Chain Reaction ◽  
Γ Irradiation ◽  
A Chain

γ-Irradiation of aqueous solutions of p-ClC6H4N2+BF4- and KI initiates a chain reaction in which dichloroazobenzene is the major product. When iodine is also present the chain reaction is longer and the major product is chloroiodobenzene . The reaction � ������������������������� I2-·+ArN2+ → I2+Ar·+N2 is suggested to be propagation step in both reactions, with Ar · reacting with I3- in the presence of iodine and with ArN2+ in its absence. The relevance of these reactions to iododediazoniation is discussed.

γ-Radiolysis of Cysteine-Cysteamine Disulfide in Aqueous Solution

1971 ◽  
Vol 49 (5) ◽  
pp. 725-730 ◽  
Author(s):  
J. W. Purdie
Keyword(s):  
Aqueous Solution ◽  
Disulfide Bonds ◽  
Low Oxygen ◽  
Chain Reactions ◽  
Mixed Disulfide ◽  
Deaerated Solution ◽  
A Chain ◽  
Protein Disulfide Bonds ◽  
High Yields ◽  
Protein Disulfide

γ-Radiolysis of a mixed disulfide, cysteine-cysteamine disulfide, in unbuffered aqueous solution (0.3 mM) was investigated in the presence and absence of oxygen. The principal products were the thiols (cysteine and cysteamine), the corresponding sulfinic and sulfonic acids, the symmetrical disulfides (cystine and cystamine) and ammonia. Cystine and cystamine were formed in very high yields in deaerated solution; (G(CySSCy) ~ 15) but addition of oxygen reduced the yield sharply and it was inversely proportional to the oxygen concentration except at very low oxygen levels. In aerated solution G(CySSCy) = 0.8. These observations were attributed to a chain reaction which was suppressed by oxygen:[Formula: see text]In the case of proteins, it was concluded that although chain reactions between RS• radicals and protein disulfide bonds were possible, they should be inhibited by oxygen.

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.

Sign in / Sign up

Export Citation Format

Share Document