Nitrox

Other solvatochromic probes have been proposed. Mukerjee et al. used nitrox-ides for this purpose, finding that their transition energies correlate linearly with Z and t (30). Brooker et al. prepared a polar merocyanine that shows a blue shift... 

Discontinued names Paraton Wofatox Veto Fosferna M50 Nitrox 80 Meister et al. 1999... 

Another potentially very useful method of studying B 12-enzymes by electron spin resonance has been developed. This method involves attaching a stable organic free radical, in all cases studied so far a nitrox-... 

FIGURE 10.3 Profiles of the order parameter (order parameter is plotted in a log scale as a function of nitrox-ide position (n) along the alkyl chain of n-SASL) at 25°C in DMPC membranes with and without 10mol% zeaxanthin. (From Subczynski, W.K. et al., Biochim. Biophys. Acta, 1068, 68, 1991. With permission.)... 

The diastereomeric 2-cli loro-2-nitroso-p-menthanc and 3-chloro-3-nitroso-p-menthane (267) epimerize during photolysis143 (equation 119) and can concurrently give the nitrox-ide 269 as detected by ESR spectrometry, which confirms the mechanism for the photolysis of geminally substituted nitroso compounds (equations 120 and 121). 

Synonyms 0, 0-dimethyl 0-p-nitrophenyl phosphorothioate Metron Nitrox parathion-methyl Metacide, metaphos... 

Nesvadba et al. (4) converted secondary amines into the corresponding nitrox-ides using 40% peracetic acid, calcium carbonate, water, and toluene. 

Aminoethanol (Ethanol a mine) Din it rate Nitroxy-ami noethane Nitrate or Nitrox yethyl ammonium... 

The present contribution is devoted to the development and application of an integrated computational approach to the EPR spectra of organic radicals in solution. Using nitrox-ides as test cases we have shown how the magnetic properties are modulated by structural, environmental and dynamical effects. The use of methods able to provide accurate results for all these contributions is thus mandatory for a reliable calculation of magnetic parameters. 

Dioxygen in its ground (triplet) state reacts as a rather stable diradical. One of its most important radical reactions is [4] in which radicals R are converted into peroxyl radicals R-OO which generally have quite different reactivities from those of the parent R species. This reaction is, in general, reversible, and stable radicals such as nitrox-ides fail to undergo reaction [1.1] to any measurable extent. 

When two or more different primary plosophores are present in a single molecule, the compd is called hybrid (eg nitrate aliphatic nitro, nitrate aromatic nitro, nitramine 8c aromatic nitroX It was established that hybrids are as powerful (or more) as pure types, although they tend to exhibit somewhat greater variability. This property of hybrids is of importance, because it extends enormously the synthetic possibilities for expls... 

Altenbach C, Greenhalgh DA, Khorana HG, Hubbell WL. A collision gradient-method to determine the immersion depth of nitrox-ides in lipid bilayers. Application to spin-labeled mutants of bac-teriorhodopsin. Proc. Natl. Acad. Sci. U.S.A. 1994 91 1667-1671. Fanucci GE, Cafiso DS. Recent advances and applications of site-directed spin labeling. Curr. Opin. Struct. Biol. 2006 16 644-653. 

The utility and simplicity of a laboratory scale chemical exchange process with chemical reflux is illustrated by the Nitrox process for the production of (23). The exchange reaction is... 

ESR spectroscopy has also been used to study dynamics in more complex systems on oxide surfaces, i.e. self-assembled molecular (SAM) films [136, 137]. Fig. 28 shows ESR spectra taken for spin labeled stearic acid, namely n-doxyl-stearic acid (n-DXSA) immersed onto a thin alumina film. These nitrox-ides, with an oxazolidinyl ring as paramagnetic group connected to different positions of the aliphatic chain, are well known as paramagnetic probes in the study of natural and synthetic membranes. The spin labeled molecules are pres-... 

Kitramino-2 nitrox/ethone, known as NENA, is a deriv of aminoethanol(qv)... 

Such studies on creatine kinase (Eq. 12-31) utilized both a bmmd Mn + ion and a nitroxide spin label to estimate distances of various protons from the nitrox-ide.683 Together with EPR measurements (Box 8-C), which gave the Mn +-nitroxide distance, a model of the ATP Mn + complex in the active site was constructed. Additional EPR experiments on Mn + complexes with ATP and ADP containing in the a, p, or y phospho groups showed that in the enzyme ATP creatine complex the metal ion is bound to all three phospho groups of ATP. It remained coordinated with the two phospho groups of ADP and also that of the phospho-creatine product in the enzyme ADP creatine-P complex as well as in the transition state, which is pictured occurring via a metaphosphate ion. ... 

Synonyms Penncap-M Bladan M Dalf Folidol-M Metacide Nitrox... 

In 1993, Georges et al. reported on the controlled radical polymerization of St initiated by benzoyl peroxide and mediated by 2,2,6,6-tetramethyl-l-piperidinyl-oxyl (TEMPO), a stable nitroxide radical [38]. TEMPO was able to bond reversibly to the polystyryl chain end and provide polystyrenes with predetermined molecular weights and low polydispersities. Nitroxides used earlier to control radical polymerizations were less successful [37, 57]. Scheme 3 illustrates the mechanism of the St polymerization, using a generalized structure of radical initiator I-I, and details the structure of TEMPO. Although several types of nitrox-... 

To understand the behavior of the mixed host-probe films, it is essential to understand the behavior of the pure films of both components. We previously investigated in detail the behavior of the pure films of 12-nitrox-ide stearate [2-( 10-carboxydecyl)-2-hexyl-4,4 -dimethyl-3-oxazolidinyloxyl] including its extraordinary temperature dependence (7, 8, 16). In this paper we extend our investigations to the pure films of other nitroxide stearic acid (and methyl ester) probes where the oxazolidine ring is attached to various carbon atoms of the stearic acid (or ester) hydrocarbon chain. This series of spin-label probes is one of those most extensively used to study cell membrane structure. It was used to define, among other things, an order parameter establishing the fluidity (17) and polarity profiles (18) of lipid bilayers. 

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