ChemInform Abstract: ESR-STUDIES OF STABLE FREE RADICAL PAIRS IN THE DIAMAGNETIC MATRIX CRYSTAL

1973 ◽  
Vol 4 (40) ◽  
pp. no-no
Author(s):  
OSAMU TAKIZAWA ◽  
JUN YAMAUCHI ◽  
HIROAKI OHYO-NISHIGUCHI ◽  
YASUO DEGUCHI
Keyword(s):  
Free Radical ◽  
Radical Pairs ◽  
Stable Free Radical ◽  
Matrix Crystal

scholarly journals ESR Studies of Stable Free Radical Pairs in the Diamagnetic Matrix Crystal

1973 ◽  
Vol 46 (7) ◽  
pp. 1991-1995 ◽  
Author(s):  
Osamu Takizawa ◽  
Jun Yamauchi ◽  
Hiroaki Ohya-Nishiguchi ◽  
Yasuo Deguchi
Keyword(s):  
Free Radical ◽  
Radical Pairs ◽  
Stable Free Radical ◽  
Matrix Crystal

Esr Indication of Heavy Metal Contamination of Urban Atmosphere

1993 ◽  
Vol 27 (7-8) ◽  
pp. 263-269 ◽  
Author(s):  
B. Iosefzon-Kuyavskaya ◽  
N. Myrlyan ◽  
A. Shames
Keyword(s):  
Heavy Metal ◽  
Air Pollution ◽  
Electron Spin Resonance ◽  
Free Radical ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Urban Atmosphere ◽  
Stable Free Radical ◽  
Spin Resonance ◽  
Line Characteristic

Electron Spin Resonance (ESR) was used for the examination oi dust samples collected from snow in an urban area. On the main doublet ESR line attributed to the signal of paramagnetic metals, a singlet line characteristic for stable free radical centers (FRC) was observed. A negative correlation of significant level between FRC signal intensity and heavy metal (HM) content was established. It was shown that FRC line intensity of dust may be used as a surrogate parameter for the estimation of air pollution by HM.

scholarly journals Microwave-Assisted Synthesis, Characterization, Antimicrobial and Antioxidant Activity of Some New Isatin Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
G. Kiran ◽  
T. Maneshwar ◽  
Y. Rajeshwar ◽  
M. Sarangapani
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Radical Scavenging ◽  
Microwave Assisted Synthesis ◽  
Stable Free Radical ◽  
Ft Ir ◽  
Antimicrobial And Antioxidant Activity ◽  
New Compounds ◽  
Isatin Derivatives

A series of β-Isatin aldehyde-N,N′-thiocarbohydrazone derivatives were synthesized and assayed for theirin vitroantimicrobial and antioxidant activity. The new compounds were characterized based on spectral (FT-IR, NMR, MS) analyses. All the test compounds possessed a broad spectrum of activity having MIC values rangeing from 12.5 to 400 μg/ml against the tested microorganisms. Among the compounds3e,3jand3nshow highest significant antimicrobial activity. The free radical scavenging effects of the test compounds against stable free radical DPPH (α,α-diphenyl-β-picryl hydrazyl) and H2O2were measured spectrophotometrically. Compounds3j,3n,3l, and3e, respectively, had the most effective antioxidant activity against DPPH and H2O2scavenging activity.

Rational Functionalization Towards Green Materials: Novel Redox Active TEMPO Stable Free Radical‐Hydrochar Composites

ChemSusChem ◽  
2021 ◽  
Author(s):  
Petre Ionita ◽  
Greta Patrinoiu ◽  
Jose M. Calderon Moreno ◽  
Simona Somacescu ◽  
Adina M. Musuc ◽  
...  
Keyword(s):  
Free Radical ◽  
Stable Free Radical ◽  
Green Materials ◽  
Redox Active

Synthesis and Characterization of Some Novel Homo- and Hetero-Diradicals of Hydrazyl and Nitroxide Type

2007 ◽  
Vol 60 (3) ◽  
pp. 173 ◽  
Author(s):  
Petre Ionita ◽  
Floriana Tuna ◽  
Marius Andruh ◽  
Titus Constantinescu ◽  
Alexandru T. Balaban
Keyword(s):  
Free Radical ◽  
Potassium Permanganate ◽  
Lead Dioxide ◽  
Magnetic Behaviour ◽  
Synthesis And Characterization ◽  
Stable Free Radical ◽  
Ms Analysis ◽  
New Compounds

Starting from the well known stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH; 2a) and its congener 2,2-diphenyl-1-(4-cyano-2,6-dinitrophenyl)hydrazyl 2b, or from their reduced hydrazine counterparts 1a,b, it was possible to obtain the p-quinonoid compounds 4a,b by oxidation with ceric (Ce4+) sulfate, which by reduction gave the corresponding hydroxyl derivatives 2-phenyl-2-(4-hydroxyphenyl)-1-picrylhydrazine 5a or 2-phenyl-2-(4-hydroxyphenyl)-1-(4-cyano-2,6-dinitrophenyl)hydrazine 5b. These hydroxyl derivatives (5a,b) react with 4-carboxy-TEMPO or 2,2-diphenyl-1-(4-carboxy-2,6-dinitrophenyl)hydrazine to form the corresponding esters 6a,b or 8a,b. These esters (6a,b and 8a,b) lead to the hybrid hetero diradicals (nitroxide–hydrazyl type) 7a,b or homo biradicals (hydrazyl–hydrazyl type) 9a,b by oxidation with lead dioxide or potassium permanganate. The new compounds were characterized by UV-vis, NMR, EPR, and MS analysis, and their magnetic behaviour was investigated.

Reduction of Riboflavin to a Stable Free Radical using X-Rays

Nature ◽  
1955 ◽  
Vol 176 (4486) ◽  
pp. 793-794 ◽  
Author(s):  
A. J. SWALLOW
Keyword(s):  
Free Radical ◽  
X Rays ◽  
Stable Free Radical

Antioxidant and Antifungal Properties of Benzimidazole Derivatives

2010 ◽  
Vol 65 (9-10) ◽  
pp. 537-542 ◽  
Author(s):  
Canan Kuş ◽  
Fatma Sözüdönmez ◽  
Benay Can-Eke ◽  
Tülay Çoban
Keyword(s):  
Lipid Peroxidation ◽  
Free Radical ◽  
Radical Scavenging ◽  
Liver Microsomes ◽  
Thiobarbituric Acid ◽  
Benzimidazole Derivatives ◽  
Rat Liver Microsomes ◽  
Inhibitory Effects ◽  
Stable Free Radical ◽  
Radical Scavenging Properties

Antioxidant and radical scavenging properties of a series of 2-[4-(substituted piperazin-/ piperidin-1-ylcarbonyl)phenyl]-1H-benzimidazole derivatives were examined. Free radical scavenging properties of compounds 11-30 and 33 were evaluated for the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide anion radical. In addition the inhibitory effects on the NADPH-dependent lipid peroxidation levels were determined by measuring the formation of 2-thiobarbituric acid reactive substances (TBARS) using rat liver microsomes. Compound 33 which has a p-fluorobenzyl substitutent at position 1 exhibited the strongest inhibition (83%) of lipid peroxidation at a concentration of 10-3 M, while the nonsubstituted analogue 13 caused 57% inhibition. This result is fairly consistent with the antimicrobial activity results against both Staphylococcus aureus and Candida albicans.

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