Isotope effect in low-temperature free-radical chlorination in a glassy ethanol matrix

1984 ◽  
Vol 20 (3) ◽  
pp. 356-358 ◽  
Author(s):  
D. A. Gordon ◽  
S. V. Demidov ◽  
A. I. Mikhailov
Keyword(s):  
Free Radical ◽  
Low Temperature ◽  
Isotope Effect ◽  
Radical Chlorination

Low temperature water-gas shift: kinetic isotope effect observed for decomposition of surface formates for Pt/ceria catalysts

2004 ◽  
Vol 269 (1-2) ◽  
pp. 63-73 ◽  
Author(s):  
Gary Jacobs ◽  
Patricia M. Patterson ◽  
Uschi M. Graham ◽  
Dennis E. Sparks ◽  
Burtron H. Davis
Keyword(s):  
Low Temperature ◽  
Isotope Effect ◽  
Kinetic Isotope Effect ◽  
Water Gas Shift ◽  
Kinetic Isotope ◽  
Ceria Catalysts ◽  
Water Gas ◽  
Temperature Water

scholarly journals Discuss the abnormal exothermic phenomenon “ cold fusion “

2021 ◽  
Vol 261 ◽  
pp. 04020
Author(s):  
Yang Liu ◽  
DongJie Liu ◽  
JiaXing Zhao ◽  
Xin Lu
Keyword(s):  
Low Temperature ◽  
Heat Release ◽  
Isotope Effect ◽  
Heat Generation ◽  
Cold Fusion ◽  
Solution Model ◽  
Calculation Formula ◽  
Research Results ◽  
The Past ◽  
Charging Rate

The research on cold fusion phenomenon has been in the past 30 years. Based on the research results of the predecessors, this article comprehensively describes the research results of the predecessors on the cold fusion phenomenon, and discusses it theoretically and experimentally. From the perspective of thermodynamics, this paper proposes to charge the palladium wire with hydrogen at low temperature to increase the frequency of abnormal heat generation, and gives a calculation formula for the hydrogen charging rate of the palladium wire. At the same time, a theoretical solution model for the isotope effect on the abnormal heat release phenomenon is proposed.

Evidence Against a Hydrogen Abstraction Mechanism in the Photorearrangement of Azoxybenzene to 2-Hydroxyazobenzene

1973 ◽  
Vol 51 (23) ◽  
pp. 3827-3841 ◽  
Author(s):  
David J. W. Goon ◽  
N. G. Murray ◽  
Jean-Pierre Schoch ◽  
N. J. Bunce
Keyword(s):  
Free Radical ◽  
Quantum Yield ◽  
Isotope Effect ◽  
Polar Solvent ◽  
Hydrogen Abstraction ◽  
Fold Increase ◽  
Transfer Mechanism ◽  
Deuterium Isotope Effect ◽  
Ring Carbon

In an attempt to distinguish between ionic and free radical mechanisms for the photorearrangement of azoxybenzene to 2-hydroxyazobenzene, aromatic azoxycompounds carrying C—H functions ortho to the azoxy linkage have been prepared and irradiated. The failure of these weaker C—H bonds to divert the reaction from its normal course argues against a hydrogen abstraction–hydroxyl transfer mechanism. This conclusion is supported by the observation of a 30-fold increase in quantum yield for 2-hydroxyazobenzene formation on changing from a non-polar to a polar solvent and by the kinetic deuterium isotope effect, which is too small for the primary isotope effect required by the abstraction mechanism. It is concluded that the experimental observations to date may most easily be accommodated in the route originally proposed by Badger and Buttery, where the rearrangement is seen as a substitution by oxygen at the ortho ring carbon.

Free radical metabolites in myocardium during ischemia and reperfusion

1991 ◽  
Vol 261 (4) ◽  
pp. L81-L86 ◽  
Author(s):  
Enno K. Ruuge ◽  
Alexander N. Ledenev ◽  
Vladimir L. Lakomkin ◽  
Alexander A. Konstantinov ◽  
Marina Yu. Ksenzenko
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Free Radical ◽  
Low Temperature ◽  
Coenzyme Q ◽  
Heart Tissue ◽  
Paramagnetic Species ◽  
Spectral Parameters ◽  
Paramagnetic Resonance ◽  
Oxygen Paradox ◽  
Electron Paramagnetic

Low-temperature electron paramagnetic resonance (EPR) spectroscopy and spin traps were used to measure paramagnetic species generation in rat hearts and isolated mitochondria. The hearts were freeze-clamped at 77 K during control perfusion by the Langendorff procedure, after 20–30 min of normothermic ischemia or 10–30 s of reperfusion with oxygenated perfusate. All EPR spectra measured at 4.5–50 K exhibited signals of both mitochondrial free radical centers and FeS proteins. The analysis of spectral parameters measured at 243 K showed that free radicals in heart tissue were semiquinones of coenzyme Q10 and flavins. The appearance of a typical “doublet” signal at g = 1.99 in low-temperature spectra indicated that a part of ubisemiquinones formed a complex with a high potential FeS protein of succinate dehydrogenase. Ischemia decreased the free radical species in myocardium ≈50%; the initiation of reflow of perfusate resulted in quick increase of the EPR signal. Mitochondria isolated from hearts during control perfusion and after 20–30 min of ischemia were able to produce superoxide radicals in both the NADH-coenzyme Q10 reductase and the bc1 segments of the respiratory chain. The rate of oxyradical generation was significantly higher in mitochondria isolated from ischemic heart. electron paramagnetic resonance; oxygen paradox; oxyradicals; rat heart; semiquinones

Free radical chlorination of methane: A demonstration

1983 ◽  
Vol 60 (7) ◽  
pp. 597
Author(s):  
Alfred R. Conklin ◽  
Alan Kramme
Keyword(s):  
Free Radical ◽  
Radical Chlorination
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