Mécanisme de la décomposition photosensibilisée au mercure du méthylvinyléther à 2537 Å

1971 ◽  
Vol 49 (12) ◽  
pp. 2125-2131 ◽  
Author(s):  
J. Castonguay ◽  
Y. Rousseau
Keyword(s):  
Free Radical ◽  
Quantum Yield ◽  
Vinyl Ether ◽  
Radical Reactions ◽  
Second Primary ◽  
Primary Process ◽  
Static System ◽  
Free Radical Reactions ◽  
Methyl Vinyl ◽  
Methyl Vinyl Ether

The study of the mercury Hg6(3P1) photosensitized decomposition of methyl vinyl ether has been studied in a static system at substrate pressures from 10 to 800 Torr. The excited precursor proposed has a calculated lifetime of 1.18 × 10−10 s and its decomposition proceeds almost exclusively through the rupture of the O—CH3 bond. A second primary process is the intramolecular formation of ethylene but it accounts only for 2% of the total ether decomposition. The major products are shown to be formed by free radical reactions and the overall reactivity appears to be very similar to that of the olefins. The results obtained with CH3SH added to the system indicate that the primary radicals are formed with a quantum yield close to unity.

The Hg 6(3P1) photosensitized decomposition of methyl vinyl ether

1970 ◽  
Vol 48 (6) ◽  
pp. 924-926 ◽  
Author(s):  
R. V. Morris ◽  
S. V. Filseth
Keyword(s):  
Hydrogen Bond ◽  
Vinyl Ether ◽  
Vapor Phase ◽  
Bond Breaking ◽  
Primary Process ◽  
Static System ◽  
Direct Production ◽  
Methyl Vinyl ◽  
Methyl Vinyl Ether ◽  
Vinoxy Radicals

The mercury 6(3P1) photosensitized decomposition of methyl vinyl ether has been studied in the vapor phase in a static system at 55 °C between 0.2 and 10.0 Torr. The principal products are propanal and ethane. It is concluded that the primary process involves the direct production of methyl and vinoxy radicals with no more than 3% participation of a competing step producing ethylene. Neither carbon–hydrogen bond breaking nor the production of primary excited molecules is observed.

scholarly journals Chemiluminescence Detection in the Study of Free-Radical Reactions. Part 1

Acta Naturae ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 90-100
Author(s):  
Leonid A. Romodin
Keyword(s):  
Free Radical ◽  
Quantum Yield ◽  
Radical Reaction ◽  
Model Systems ◽  
Biological Model ◽  
Radical Reactions ◽  
Reaction Products ◽  
Chemiluminescence Detection ◽  
Ferrous Ions ◽  
Free Radical Reactions

The present review, consisting of two parts, considers the application of the chemiluminescence detection method in evaluating free radical reactions in biological model systems. The first part presents a classification of experimental biological model systems. Evidence favoring the use of chemiluminescence detection in the study of free radical reactions, along with similar methods of registering electromagnetic radiation as electron paramagnetic resonance, spectrophotometry, detection of infrared radiation (IR spectrometry), and chemical methods for assessing the end products of free radical reactions, is shown. Chemiluminescence accompanying free radical reactions involving lipids has been the extensively studied reaction. These reactions are one of the key causes of cell death by either apoptosis (activation of the cytochrome c complex with cardiolipin) or ferroptosis (induced by free ferrous ions). The concept of chemiluminescence quantum yield is also discussed in this article. The second part, which is to be published in the next issue, analyzes the application of chemiluminescence detection using luminescent additives that are called activators, a.k.a. chemiluminescence enhancers, and enhance the emission through the tripletsinglet transfer of electron excitation energy from radical reaction products, followed by light emission with a high quantum yield.

Thermal gravimetric analysis of in-situ crosslinked nanocellulose whiskers • poly(methyl vinyl ether-co-maleic acid) • polyethylene glycol

TAPPI Journal ◽  
2011 ◽  
Vol 10 (4) ◽  
pp. 29-33
Author(s):  
LEE A. GOETZ ◽  
AJI P. MATHEW ◽  
KRISTIINA OKSMAN ◽  
ARTHUR J. RAGAUSKAS
Keyword(s):  
Thermal Stability ◽  
Polyethylene Glycol ◽  
Vinyl Ether ◽  
Thermal Gravimetric Analysis ◽  
Maleic Acid ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Methyl Vinyl ◽  
Methyl Vinyl Ether

The thermal stability and decomposition of in-situ crosslinked nanocellulose whiskers – poly(methyl vinyl ether-co-maleic acid) – polyethylene glycol formulations (PMVEMA-PEG), (25%, 50%, and 75% whiskers) – were investigated using thermal gravimetric analysis (TGA) methods. The thermal degradation behavior of the films varied according to the percent cellulose whiskers in each formulation. The presence of cellulose whiskers increased the thermal stability of the PMVEMA-PEG matrix.

The initial reaction mechanism and thermal sensitivity of a fluoropolymer-containing energetic molecular system: the coupling effect of interfacial interactions and free radical reactions

CrystEngComm ◽  
2021 ◽  
Vol 23 (16) ◽  
pp. 3006-3014
Author(s):  
Wen Qian
Keyword(s):  
Free Radical ◽  
Coupling Effect ◽  
Molecular System ◽  
Thermal Sensitivity ◽  
Radical Reactions ◽  
Initial Reaction ◽  
Interfacial Interactions ◽  
Free Radical Reactions ◽  
Molecular Systems ◽  
Reactive Molecular Dynamics

A strategy combining classic and reactive molecular dynamics is applied to find the coupling effect of interfacial interactions and free radical reactions during the initial thermal decomposition of fluoropolymer-containing molecular systems.

Further studies on free-radical pathology in the major central nervous system disorders: effect of very high doses of methylprednisolone on the functional outcome, morphology, and chemistry of experimental spinal cord impact injury

1982 ◽  
Vol 60 (11) ◽  
pp. 1415-1424 ◽  
Author(s):  
H. B. Demopoulos ◽  
E. S. Flamm ◽  
M. L. Seligman ◽  
D. D. Pietronigro ◽  
J. Tomasula ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Free Radical ◽  
Tissue Injury ◽  
Functional Restoration ◽  
Radical Reactions ◽  
Free Radical Reactions ◽  
Cord Injury

The hypothesis that pathologic free-radical reactions are initiated and catalyzed in the major central nervous system (CNS) disorders has been further supported by the current acute spinal cord injury work that has demonstrated the appearance of specific, cholesterol free-radical oxidation products. The significance of these products is suggested by the fact that: (i) they increase with time after injury; (ii) their production is curtailed with a steroidal antioxidant; (iii) high antioxidant doses of the steroidal antioxidant which curtail the development of free-radical product prevent tissue degeneration and permit functional restoration. The role of pathologic free-radical reactions is also inferred from the loss of ascorbic acid, a principal CNS antioxidant, and of extractable cholesterol. These losses are also prevented by the steroidal antioxidant. This model system is among others in the CNS which offer distinctive opportunities to study, in vivo, the onset and progression of membrane damaging free-radical reactions within well-defined parameters of time, extent of tissue injury, correlation with changes in membrane enzymes, and correlation with readily measurable in vivo functions.

Solvent Effects on the Oxidative Free Radical Reactions of 2-Amino-1,4-naphthoquinones.

ChemInform ◽  
2005 ◽  
Vol 36 (14) ◽  
Author(s):  
Chao-Ming Tseng ◽  
Yi-Lung Wu ◽  
Che-Ping Chuang
Keyword(s):  
Free Radical ◽  
Solvent Effects ◽  
Radical Reactions ◽  
Free Radical Reactions
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