69116-04-7Relevant academic research and scientific papers
Effect of the structure of nitroxyl radicals on the kinetics of their acid-catalyzed disproportionation
Tikhonov, Ivan V.,Sen', Vasily D.,Borodin, Leonid I.,Pliss, Evgeny M.,Golubev, Valery A.,Rusakov, Alexander I.
, p. 114 - 120 (2014/02/14)
Acid-catalyzed disproportionation of cyclic nitroxyl radicals R 2NO-￠ includes the half-reactions of their oxidation to oxoammonium cations R2NO+ and reduction to hydroxylamines R2NOH. For many nitroxyl radicals, this reaction is characterized by its-～100% reversibility. Quantitative characteristics of acid-base and redox properties of the whole redox triad may be obtained from research of kinetics and equilibrium of this reaction. Here, we have examined the kinetics for the disproportionation of twenty piperidine-, pyrroline-, pyrrolidine-, and imidazoline nitroxyl radicals in aqueous H2SO 4, and interpreted it in terms of the excess acidity function X. The rate-limiting step of this reaction is R2NO-￠ oxidation by its protonated counterpart R2NOH+-￠. Kinetic stability of R2NO-￠ in acidic media depends on the basicity of nitroxyl group. This basicity is influenced predominantly by protonation of another, more basic group in radical structure, and its proximity to nitroxyl group. The discovered estimates of pK values for radical cations R2NOH+-￠ (from-5.8 to-12.0) indicate a very low basicity of nitroxyl groups in all commonly used R2NO -￠. For the first time, a linear correlation is obtained between the one-electron reduction potentials of oxoammonium cations and the basicity of nitroxyl groups of related radicals. Copyright
Synthesis of Deprenyl-like nitroxide free radicals and their diamagnetic derivatives
Sar, Cecilia P.,Kalai, Tamas,Jekoe, Jozsef,Hideg, Kalman
experimental part, p. 47 - 59 (2012/03/22)
Synthesis of paramagnetically modified deprenyl and oxotremorine is reported. Starting from 5- and 6-membered 2,5-disubstituted nitrones 1, 6 or 4-phenyl-2,5,5-trimethyl-1H-pyrroline 1-oxide 11 deprenyl or oxotremorine like nitroxides were synthesized via
The exchange reaction of hydrogen atoms in the system sterically hindered hydroxylamine - Nitroxyl radical
Malievskii,Koroteev
, p. 1287 - 1291 (2007/10/03)
The rate constants of the direct and reverse exchange reactions of the hydrogen atom in the system sterically-hindered nitroxyl radical - hydroxylamine of the quinoline, imidazoline, pyrrolidine, and piperidine series as well as diarylhydroxylamine were determined. A scale of the reductive abilities of the hydroxylamines was established. A low value of the isotope effect is typical of the reactions of hydrogen exchange in the systems hydroxylamine - nitroxyl radical.
