scholarly journals Studies on Stable Free Radicals. II. Reactivity of Stable Nitroxide Radicals and NMR Spectra of Reaction Products

1969 ◽  
Vol 42 (6) ◽  
pp. 1640-1643 ◽  
Author(s):  
Keisuke Murayama ◽  
Syoji Morimura ◽  
Takao Yoshioka
Keyword(s):  
Free Radicals ◽  
Nmr Spectra ◽  
Reaction Products ◽  
Nitroxide Radicals ◽  
Stable Free Radicals ◽  
Stable Nitroxide

scholarly journals Studies on Stable Free Radicals. XI. ESR Spectra of Stable Nitroxide Biradicals

1972 ◽  
Vol 45 (6) ◽  
pp. 1764-1766 ◽  
Author(s):  
Toshimasa Toda ◽  
Eiko Mori ◽  
Keisuke Murayama
Keyword(s):  
Free Radicals ◽  
Esr Spectra ◽  
Stable Free Radicals ◽  
Stable Nitroxide

The Use of Stable Free Radicals to Determine Motion in Polymeric Systems

1975 ◽  
Vol 48 (5) ◽  
pp. 1078-1089 ◽  
Author(s):  
Wilmer G. Miller ◽  
Zorica Veksli
Keyword(s):  
Glass Transition ◽  
Free Radicals ◽  
Diffusion Coefficients ◽  
Molecular Motion ◽  
Translational Diffusion ◽  
Glassy Polymers ◽  
Spin Labels ◽  
Polymeric Systems ◽  
Stable Free Radicals ◽  
Stable Nitroxide

Abstract The application of thermally and chemically stable nitroxide free radicals to a variety of motional problems in polymeric systems has been investigated. Solvents do not cause significant motion in glassy polymers until the glass transition is lowered to the temperature of measurement. With nonsolvents the results depend on the nature of the sample preparation as well as on the polymer-solvent pair. Molecular motion at the surface of a polymer immersed in a nonsolvent was investigated by means of surface-labeled latex spheres. The application of nitroxides as spin labels to the measurement of translational diffusion coefficients is explored and discussed. Finally, the application of the technique to adsorption and motion of surfactants and polymers onto surfaces is reported.

Synthesis and Application of Stable Nitroxide Free Radicals Fused with Carbocycles and Heterocycles

2019 ◽  
Vol 23 (4) ◽  
pp. 480-501 ◽  
Author(s):  
Balázs Bognár ◽  
Györgyi Úr ◽  
Cecília Sár ◽  
Olga H. Hankovszky ◽  
Kálmán Hideg ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Building Blocks ◽  
Spin Labels ◽  
Spin Probes ◽  
Electroactive Materials ◽  
The Past ◽  
Synthetic Methodologies ◽  
Stable Free Radicals ◽  
Stable Nitroxide

Stable nitroxide free radicals have traditionally been associated with 2,2,6,6- tetramethylpiperidine-1-oxyl (TEMPO) or its 4-substituted derivatives as relatively inexpensive and readily accessible compounds with limited possibilities for further chemical modification. Over the past two decades, there has been a resurgence of interest in stable free radicals with proper functionalization tuned for various applications. The objective of this review is to present recent results with synthetic methodologies to achieve stable nitroxide free radicals fused with aromatic carbocycles and heterocycles. There are two main approaches for accessing stable nitroxide free radicals fused with arenes, e.g., isoindoline- like nitroxides: further functionalization and oxidation of phthalimide or inventive functionalization of pyrroline nitroxide key compounds. The latter also offers the constructions of versatile heterocyclic scaffolds (furan, pyrrole, thiophene, 1,2-thiazole, selenophene, pyrazole, pyrimidine, pyridine, pyridazine, 1,5-benzothiazepine) that are fused with pyrroline or tetrahydropyridine nitroxide rings. The possible applications of these new stable nitroxide free radicals, such as covalent spin labels and noncovalent spin probes of proteins and nucleic acids, profluorescent probes, building blocks for construction of dual active drugs and electroactive materials, and substances for controlled free radical polymerization, are discussed.

Reaction of Radical Acceptors with Polymer Radicals formed by Mechanical Degradation of Vulcanizates

1971 ◽  
Vol 44 (3) ◽  
pp. 668-674
Author(s):  
D. R. Razgon ◽  
V. F. Drozdovskii
Keyword(s):  
Free Radicals ◽  
Mechanical Degradation ◽  
Nitroxide Radicals ◽  
Epr Method ◽  
Temperature Range ◽  
Hydrocarbon Radicals ◽  
Phenoxy Radicals ◽  
Kinetics Of ◽  
Stable Nitroxide

Abstract The authors investigated, by the EPR method, the kinetics of the accumulation and subsequent deterioration of polymer radicals, resulting from the mechanical degradation of sulfur and peroxide vulcanizates of SKMS-3 ARKM-15 rubbers at 80 ° K. The reaction of these radicals with a number of acceptors were also studied. The polymer radicals, independently of their nature, will deteriorate at temperatures near the Tg. Polysulfide radicals are completely destroyed at 240–250° K, the hydrocarbon radicals at 220–235° K, and the peroxide ones at 200–210° K. The peroxide radicals will react, at 80° K, with Ionol and alkylphenol disulfides to form phenoxy radicals, and with trichlorothiophenol to produce thiol radicals, but will not react with the stable nitroxide radicals or with di-(trichlorophenyl) disulfides. The carbon free radicals will react, at 150–200 ° K, with trichlorothiophenol and with alkylphenol disulfides, resulting in formation of polysulfide radicals, and, at 80° K, they will react with stable nitroxide radicals to form 2,2,6,6-tetramethyl-4-hydroxypiperidyl. The polysulfide radicals, within a temperature range of 80 to 250° K, do not react to any appreciable degree with any of the radical acceptors investigated.

A study of reaction of aromatic polynitro compounds with tributylstannyl hydride

1985 ◽  
Vol 50 (11) ◽  
pp. 2598-2606 ◽  
Author(s):  
Vladimír Macháček ◽  
Antonín Lyčka ◽  
Milan Nádvorník
Keyword(s):  
Nmr Spectra ◽  
Reaction Products ◽  
Tetramethylammonium Bromide ◽  
Composition And Structure

1H, 13C, 15N, and 119Sn NMR spectra have been used to study composition and structure of reaction products from 1,3,5-trinitrobenzene, methyl 2,4,6-trinitrobenzoate, 1-dimethylamino-2,4,6-trinitrobenzene, 1-methoxy-2,4,6-trinitrobenzene, 1-chloro-2,4,6-trinitrobenzene, 2,4,6-trinitrotoluene, 3,5-dinitrobenzonitrile and methyl 3,5-dinitrobenzoate with tributylstannyl hydride in the presence of tetramethylammonium bromide.

A 15N, 13C, and 1H NMR study of reaction products from arylguanidines and chloroformate esters

1991 ◽  
Vol 56 (7) ◽  
pp. 1505-1511 ◽  
Author(s):  
Antonín Lyčka ◽  
Karel Palát
Keyword(s):  
1H Nmr ◽  
Nmr Spectra ◽  
Reaction Products ◽  
H Nmr ◽  
Nmr Study

The 15N, 13C, and 1H NMR spectra of the reaction products from arylguanidines with two mols of chloroformate esters have been measured. With application of the corresponding 15N isotopomer it has been proved that the reaction products have the structures IIIa-IIIc.

Neonatal blood is more resistant to oxidative stress induced by stable nitroxide radicals than adult blood

2007 ◽  
Vol 277 (3) ◽  
pp. 233-237 ◽  
Author(s):  
Tali Silberstein ◽  
David Mankuta ◽  
Alexander I. Shames ◽  
Gertz I. Likhtenshtein ◽  
Dan Meyerstein ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitroxide Radicals ◽  
Neonatal Blood ◽  
Stable Nitroxide
Sign in / Sign up

Export Citation Format

Share Document