Reactions of Free Radicals with Olefins. Reactions of t-Butoxy and t-Butyl Peroxy Radicals with 4-Vinylcyclohexene1

1961 ◽  
Vol 26 (7) ◽  
pp. 2185-2190 ◽  
Author(s):  
J. REID SHELTON ◽  
J. NEIL HENDERSON
Keyword(s):  
Free Radicals ◽  
Peroxy Radicals

Organic free radicals and proteins in biochemical injury: electron- or hydrogen-transfer reactions?

1985 ◽  
Vol 311 (1152) ◽  
pp. 545-563 ◽  
Keyword(s):  
Free Radicals ◽  
Hydrogen Transfer ◽  
Superoxide Radical ◽  
Water Soluble ◽  
Peroxy Radicals ◽  
Redox Potentials ◽  
Thiol Compounds ◽  
Neutral Aqueous Solution ◽  
Aliphatic Carbon ◽  
The One

The reactions of organic free radicals, acting as either reductants or oxidants, have been studied by pulse radiolysis in neutral aqueous solution at room temperature. Many hydroxyl-substituted aliphatic carbon-centred radicals and one-electron adducts have been shown to be good one-electron reductants, while several oxygen-, sulphurand nitrogen- (but not carbon-) centred free radicals have been shown to be good one-electron oxidants. Several carbon-centred radicals can be reduced rapidly by hydrogen transfer, from undissociated thiol compounds which can thus act as catalysts facilitating the overall reduction of a carbon-centred radical by an electron-donating molecule. Kinetic considerations influenced by the one-electron redox potentials of the radical-molecule couples involved, determine whether a particular reaction predominates. In this paper examples of such reactions, involving a water-soluble derivative of vitamin E (Trolox C) and the coenzyme NADH, are described, together with studies showing ( a ) that even in complex multi-solute systems some organic peroxy radicals can inactiviate alcohol dehydrogenase under conditions where the superoxide radical does not, and ( b ) the superoxide radical can be damaging if urate is also present, and this damage can be reduced by the presence of superoxide dismutase.

Reactions of alkyl free radicals with 4-vinylcyclohexene

1968 ◽  
Vol 46 (24) ◽  
pp. 3833-3839 ◽  
Author(s):  
J. Reid. Shelton ◽  
Earl E. Borchert
Keyword(s):  
Free Radicals ◽  
Hydrogen Abstraction ◽  
Product Distribution ◽  
Effect Of Temperature ◽  
Coupling Reactions ◽  
Peroxy Radicals ◽  
Alkyl Radicals ◽  
Thiyl Radicals ◽  
Dissociation Energies ◽  
Tertiary Alkyl

Tertiary alkyl and cyanoalkyl free radicals prepared from t-butyl peroxypivalate and azobisisobutyronitrile were reacted with 4-vinylcyclohexene (1) for comparison with results previously obtained in the reaction of certain alkyl, alkoxy, peroxy, and thiyl radicals with this model olefin. The (CH3)3C• and (CH3)2(CN)C• radicals (like thiyl but in contrast to t-butoxy and t-butyl peroxy radicals) added to the vinyl double bond with subsequent abstraction of hydrogen by the resulting secondary alkyl radicals to give RH adducts along with higher molecular weight material.Vinylcyclohexenyl radicals formed by hydrogen abstraction from 1 reacted mainly by coupling to form dehydro dimers. They also formed substituted products by coupling with cyanoisopropyl radicals, but not with t-butyl radicals. The presence of both stabilized and unstabilized alkyl radicals of both secondary and tertiary types in these reactions with 1 permitted the observation of differences in the relative tendencies of these types of radicals to participate in addition, hydrogen abstraction, disproportionation, and coupling reactions. The observed effect of temperature (60 and 90°) on product distribution, together with estimated bond dissociation energies, suggest that the addition of cyanoisopropyl radicals to 1 is a reversible process.

Free radicals in the reaction between t-butyl hydroperoxide and titanous ion: Some observations by electron spin resonance spectrometry

1965 ◽  
Vol 18 (8) ◽  
pp. 1177 ◽  
Author(s):  
MFR Mulcahy ◽  
JR Steven ◽  
JC Ward
Keyword(s):  
Aqueous Solution ◽  
Free Radicals ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Peroxy Radicals ◽  
Methyl Radicals ◽  
Methyl Radical ◽  
Butyl Hydroperoxide ◽  
Spin Resonance ◽  
G Value

The reaction between t-butyl hydroperoxide and titanous ion in aqueous solution produces free methyl radicals detectable by electron spin resonance spectrometry (Dixon and Norman). However, the presence of titanous ion in concentrations greater than 0.01M broadens the spectrum of the methyl radical, causing it effectively to disappear at titanous concentrations greater than 0.1M. At hydroperoxide concentrations above 0.25M t-butyl peroxy radicals (identified by a strong single-line spectrum with g-value 2.0136) are produced by the reaction ���������� R. + (CH3)3COOH → RH + (CH3)3COO. Their concentration reaches a maximum about 1 sec after the concentration of the methyl radicals has fallen to an undetectable value and their half-life (≈ 5 sec) is about ten times that of the methyl radicals.

STRESS PADA LANSIA MENJADI FAKTOR PENYEBAB DAN AKIBAT TERJADINYA PENYAKIT

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Nur Hidaayah
Keyword(s):  
Drinking Water ◽  
Free Radicals ◽  
The Elderly ◽  
The State ◽  
Young Age ◽  
Fresh Fruit ◽  
Stress Conditions ◽  
Harmful Substances ◽  
Available Resources

Stress conditions in the elderly means an imbalance condition of biological, psychological, and social are closely related to the response to the threats and dangers faced by the elderly. Pressure or interference that is not fun is usually created when the elderly see a mismatch between the state and the 3 systems available resources. Maintenance actions that need to be done there are 2 types, namely : prevention of exposure to a stressor (precipitation factor) and serious treatment of the imbalance condition/ illness (precipitation factor). Prevention includes: sports, hobbies, friendship, avoid eating foods high in free radicals and harmful substances, sex and setting arrangements adequate rest. Habits of the above if done at a young age to avoid exposure to stress in the elderly. Treatment of the imbalance condition / illness, include : drinking water, meditation, eating fresh fruit, and adequate rest.

Magnetic properties of free radicals

1988 ◽  
Vol 155 (5) ◽  
pp. 180-180
Author(s):  
Anatolii L. Buchachenko
Keyword(s):  
Magnetic Properties ◽  
Free Radicals
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