The Novel Stable Nitroxide Radicals as Perspective Spin Probes for Study of Orientation Order of Liquid Crystals and Polymers

2011 ◽  
Vol 540 (1) ◽  
pp. 196-204 ◽  
Author(s):  
Natalia A. Chumakova ◽  
Daria A. Pomogailo ◽  
Tatiana S. Yankova ◽  
Andrey Kh. Vorobiev
Keyword(s):  
Liquid Crystals ◽  
The Novel ◽  
Spin Probes ◽  
Nitroxide Radicals ◽  
Orientation Order ◽  
Stable Nitroxide

Line broadening in the electron resonance spectra of spin probes dissolved in anisotropic media: the effect of nuclear spin quantization

1977 ◽  
Vol 353 (1672) ◽  
pp. 87-102 ◽  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nuclear Spin ◽  
Dynamic Properties ◽  
Orientational Order ◽  
Anisotropic Media ◽  
Approximate Theory ◽  
Spin Probes ◽  
Line Broadening ◽  
Electron Resonance

The line broadening in the electron resonance spectra of monoradicals dissolved in anisotropic media, such as liquid crystals, provides a valuable probe of both the orientational order and the molecular dynamics. However, the fast-motion relaxation theory employed to extract this information from the linewidths assumes that the nuclear spin is quantized along the direction of the magnetic field. This approximation is only correct when the symmetry axis of a uniaxial liquid crystal is either parallel or perpendicular to the field. We have therefore removed this assumption and have developed a general theory of line broadening valid for all orientations of the liquid crystal. The theory is then used to evaluate the angular dependence of the linewidths and this is compared with the dependence predicted by the approximate theory, for two classes of nitroxide spin probes. These comparisons reveal that for steroidal spin probes the error, introduced by assuming the nuclear spin to be quantized along the field, is confined to the dynamic properties derived from the linewidths. In contrast, significant errors appear in both the dynamic and static properties obtained from an analysis of the linewidth variations for fatty acid spin probes based on the approximate theory. It would seem that the exact theory must be employed to obtain precise information from linewidth investigations of liquid crystals, except when the orientational order is extremely small.

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

Mechanism of the inhibition of polymerization of vinyl monomers initiated by benzoyl peroxide by stable nitroxide radicals

1983 ◽  
Vol 25 (10) ◽  
pp. 2497-2504 ◽  
Author(s):  
A.V. Trubnikov ◽  
M.D. Gol'dfein ◽  
N.V. Kozhevnikov ◽  
A.D. Stepukhovich
Keyword(s):  
Benzoyl Peroxide ◽  
Vinyl Monomers ◽  
Nitroxide Radicals ◽  
Stable Nitroxide
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