572. Electron spin resonance studies of oxidation. Part I. Alcohols

Abstract

When acidic solutions of titanous ion and hydrogen peroxide react immediately before passing through the cavity of an electron spin resonance spectrometer, a singlet is observed in the spectrum which is attributed to the hydroxyl radical. The addition of alcohols to the reactants results in the replacement of this signal by the spectra of organic radicals formed by abstraction of a hydrogen atom from a C-H bond or (in one case) by addition to C=C. Analysis of the spectra gives evidence about the structures of the radicals and hence about the course of the reaction.Coupling constants for protons in different environments are reported and discussed.* The stability and resolution of the spectrometer have been greatly improved since our preliminary result was reported.4

EPR of Fast Repair Reactions by Sulfhydryl and Disulfide Compounds in Aqueous Solutions

“…The two typical reactions of OH radicals with organic molecules are abstraction of atomic hydrogen, as in the case of ethanol (13), and addition to a double bond, as shown for thymine by Nicolau et al (23). In contrast to this the radical NH 2 ' reacts mainly by addition to a double bond (23) with the exception of SH-compounds.…”

“…In the present paper we report experiments performed by means of EPR spectroscopy in conjunction with a flow technique as described by Dixon anel Normall (13) and byNormanand West (14), This technique allows detection of short lived free radicals produced by the attack with OH' l11ld NH2' anel to follow their reaction with organic molecules, The OH anel NH2 radicals are produced by the folhwing reactions:…”

Electron spin resonance spectra of polymer radicals in aqueous solution

“…Fro m the 51 -~I line widths, it is obvious that, as in NMR of polym e r solutions [14], the segmental motion is nearly as efficient as the tumbling motion of small molec ules in narrowing line widths_ Kinetic considerations will be dealt with elsewhere. By way of summary, it should be noted that the identity of the lines previously taken as hydroxyl [2] is incertain [ISa]. At least one of the lines seems to be that of a radical complexed with titanium [ll].…”

“…Following the initial discovery by Dixon and Norman [1],2 electron spin resonance spec tra of numero us free radicals have been observed by rapidly mixing solutions of titanous ion, hydrogen peroxide and an appropriate su bstrate [2][3][4][5][6][7][8]. The hydroxyl radicals, identification of which is debatable, react by abstraction [1], addition [7,8] and perhaps electron transfer [3].…”

Research on the Stability of High Strength H2o2

“…iI iI 13 3 -I 3. Two-week stability tests w'ere thhen set up at the three temperatures noted in (2) above, usin4 as test samples 90% concentration stabilized.…”