[en] The use of CH₂-N(O)-t-Bu nitrone (MN) as a spin trap permits to accept those radicals which can't be captured by nitroso compounds because of their oxidic properties of the latter ones. C₂H₅C(OH)CH₃, CH₃CO, C₂H₅, CH₃COCHCH₃ radicals are found in methylethylketone (MEK) irradiated at +20 deg C with the help of MH, and t-BuC(OH)CH₃, CH₃CO and t-Bu radicals-in methylbutylkeltone. It is that in MEK C₂H₅C(OH)CH₃ radials are formed in two ways: during reactions of ketone anion-radicals and from triplet-excited molecules

[en] With the help of spin traps in polychloralkanes CCl₄, CHCl₃, CH₂Cl₂, 1.2-dichlorathene, as well in freons CCl₂FCClF₂ and CCl₃CF₃, irradiated with γ-rays in the liquid phase identified ares short-lived radicals: Cl atoms and radicals, arizing during the Cl atom detachment, i.e. CCl₃, CHCl₂, CH₂Cl etc. or during C-C bond break in CCl₃CF₃(CCl₃ and CF₃)

[en] Effect of lithium nitrate and lithium bromide on yields of radicals in γ-radiolysis of methanol and aqueous-methanol solutions at 77 K has been investigated by the EPR technique to gain information on CH₃OH⁺ primary ion reactions. The reactions are shown to occur between CH₃OH⁺ and the NO₃^- and Br^- ions. The rate constants ratios K(CH₃OH⁺ + Br)/K(CH₃OH⁺ + CH₃OH) and K(CH₃OH⁺ + NO₃^-)/(CH₃OH⁺ + CH₃OH) are found to be 12+-2 and 5+-1, respectively. With growth of the NO₃^- concentration as well as in the system CH₃OH + IM LiNO₃ + LiBr the ion-radical NO₃^-2 has been formed in equivalent amounts instead of the NO₂ radical. The correlation between yield G(NO₂) and the concentration of addition introduced make possible to derive conclusion that the formation of NO₂ is associated with transfer of proton through the hydrogen bonds system

[en] The influence of water on the yield of alkyl radicals in mixtures of sulphuric acid with an alcohol, exposed to gamma-radiation at -196 deg C, has been investigated by ESR techniques. The yields of radicals are shown to depend on the ratio between the concentrations of water and alcohol in the system. With a higher content of water in the system, the yields of alkyl radicals go down and those of alcohol radicals increase. It is shown that in the investigated system take place competitive reactions ROH₂⁺ + e^- → R + H₂O; e^- + H₃O⁺ → H₂O + H; ROH₂⁺ + e^- → ROH + H. Usual competition between H₃O⁺ and ROH₂⁺ takes place onlye when [H₂O]/[ROH] (<=) 0.42. The possibility of the epithermal electron reacting with the molecules of protonated alcohol is discussed

[en] The radiolysis mechanisms of organic compounds of different types using spin traps are studied. This method is shown to be easy and effective when investigating short-lived radicals in the liquid phase. The method of spin traps permits to identify a much more considerable number of radicals in different systems than the traditional ESR method in case of frosen system radiolysis. The concrete compounds, which serve as spin traps (aliphatic tertiary nitroso compounds, aromatic nitroso compounds etc.) are considered. The chemical properties of these compounds and the limits of their applicability are considered. The radiolysis mechanisms of compounds of different classes (alcohols, ethers, nitriles, thiocompounds, carbonyl compounds, aromatic hydrocarbons etc.) are considered

No abstract available

[en] Using the ESR method the formation and reactions of cation-radicals of dimethyl formamide and tetra-methyl urea in γ-irradiated at 77 K freon solutions: ion-molecular reactions during irradiation, as well as during phase transition in matrix, and intramolecular transfer of hydrogen, have been investigated. In pure amides in liquid phase fragmentation with the formation of Me₂N prevails, which is shown using spin traps

[en] Short note

[en] Radical formation in γ-irradiated liquid acetone is investigated using the method of spin traps of tert.-nitrosobutane (TNB) and butylnitrosobenzol (B B). Adducts with CH₃ and CH₂COCH₃ radicals are observed in the presence of BNB, and in the presence of TBN - only adducts with CH₂COCH₃ and t-Bu₂NO radicals and only traces of CH₃ radicals. Exitation acceptors (naphthalene and anthracene) do not effect radical adduct yields. Initial CH₃ yield is determined and constant ratios are obtained using competitive kinetics. Conclusion is made that during acetone radiolysis in the presence of spin traps only radicals, having ion predecessors, are observed

[en] Using nitrosodurene (ND) and C-phenyl-tertbutylnitrone (PBN) as spin traps in was shown that the γ-irradiation of benzene and toluene resulted in adducts with the phenyl radicals and with the phenyl type and benzyl radicals, respectively. No adducts with the cyclohexadienyl radicals were detected. The γ-irradiation of benzene and toluene in the presence of tertnitrosobutane (TNB) gave the t-Bu₂NO radicals, their yield being above 99% with respect to the total yield (G=1.5 radicals/100 eV). The yields of the TNB adducts with radicals from matrix were found to be about 0.01 radicals/100 eV and to be lower then in the presence of ND and PBN