[en] The main end products of the radiolysis of concentrated MgCl₂ solutions are H₂ and so-called ''active chlorine,'' existing in three equilibrium forms: Cl₃^-, Cl₂, and HOCl. The predecessors of the active chlorine are ion-radicals Cl₂^-, which, as shown by the pulse radiolysis study, disappear in a second-order reaction accompanied by a symbatic increase in the optical absorption in 240-270 nm region. This absorption disappears for a few minutes, and the disappearance curve is 20-40% modulated by oscillations with a period of 2 min. The lifetime of the absorption and the oscillation amplitude are very dependent on the dose of the preliminary irradiation. Periodic oscillations are also observed on the accumulation curve of stable products during continuous irradiation by Bremsstrahlung from an electron beam on the Cockroft-Wolton accelerator. These concentrational oscillations are probably due to periodic oxidation-reduction processes, including the reactions between H₂O₂ and oxidized forms of chlorine, formed during the radiolysis of MgCl₂ solution

[en] Irradiation of the samples with Co-60 gamma rays was performed at 77 and at 300⁰K. The ESR spectra were recorded. All the investigated substances were liquids at 300⁰K. In all compounds studied at 77 K, stabilized radicals were formed. Increasing the temperature of these samples to 300 K led to the destruction of most of their paramagnetic centers. Radiolysis in liquid at 300 K led to the formation of stable radicals in 4 out of 11 compounds tested. Formation by radiolysis of radicals stable at 300 K is observed in compounds containing a tertiary or quaternary carbon atom. The observed radicals are stable not only in solution but also in the gas phase. These radicals do not react with oxygen during prolonged storage or during gamma radiation at 300 K. 1 figure, 1 table

[en] The principal short-lived products from the radiolysis of alkali-metal halide melts are solvated electrons (e/sub s/^-), which are particles with the F-center type structure, and molecular anion-radicals of the halogen (GAMMA₂^-); these are formed in the reactions: (1)GAMMA^- → GAMMA⁰ + e^-; (2) e^- → e/sub s/^-; (3) GAMMA⁰ + GAMMA^- → GAMMA₂^-. Solvated electrons are strong reducing agents, and they disappear almost completely in rections with the metal cations. Here we are presenting results from a study of the properties of the oxidizer products GAMMA₂^-, by means of a pulse radiolysis method. The optical spectra of the oxidizer components of radiolysis of alkali-metal halide melts, the molecular anion-radicals GAMMA₂^-, are similar to the spectra of the corresponding species in aqueous solutions. Rate constants have been measured for the disappearance of GAMMA₂^-, which goes forward mainly in the reaction of GAMMA₂^- with the reduced form of the cation. In the presence of alkaline-earth metal cations, owing to the fast disproportionation of their reduced form, there is a greater contribution from the relatively slow reaction of disproportionation of GAMMA₂^-, leading to an observed retardation of the rate of GAMMA₂^- disappearance and an increase in the yield of molecular halogen

[en] Technetium exhibits high catalytic activity in a number of processes, e.g., in the hydrogenation and dehydrogenation of hydrocarbons and alcohols. The absence of information about the physicochemical properties of the surface of supported Tc catalysts, however, makes it difficult to interpret the experimental data and to decide on the best means of preparing the catalysts and selecting the support. The object of the present work has been to study the dispersity, which is one of the most important characteristics of the state of metals on surfaces. For technetium catalysts, the surface character of the support (specific surface and porosity) determines the Tc particle size distribution. There is satisfactory agreement between the results obtained by two independent methods of measuring the dispersity--electron microscopy and chemisorption

[en] The synthesis is reported of 5-S-cysteamine-6-hydroxythymine (RST) and its identification in the radiolysis of solutions containing cysteamine and thymine. 17 references, 6 figures, 2 tables

[en] The abstraction of a deuterium atom from the CD₃ group in deuterotoluenes is more accelerated by pressure than the abstraction of a hydrogen atom from the toluene methyl group, which is reflected in a decrease in the kinetic isotope effect k/sub H//k/sub D/ with increasing pressure. The value for k/sub H//k/sub D/ = ([DMPC]/[AP])H/([DMPC]/[AP])/sub D/ were determined by measurement of the amounts of dimethylphenylcarbinol (DMPC) and acetophenone (AP) formed upon the decomposition of 0.1 mole/liter dicumyl peroxide in C₆H₅CH₃, C₆H₅CD₃, and C₆D₅CD₃ at 399⁰K

[en] The present investigation was devoted to studying the changes in the structure of the intial uranyl carboxylate UO₂(CH₃COO)₂.2H₂O connected with the introduction of neutral nitrogen-containing ligands into the coordination sphere of the uranyl group, and also the nature of the coordination and the composition of the additional ligands on the course of the thermal decomposition of the complex. Complex compounds of uranyl acetate with dimethylacetamide and urea that have been described previously have been synthesized. On the basis of x-ray structural results the following formulas have been established for the compounds obtained: [UO₂(CH₃COO)₂.DMAA]₂ and [UO₂(CH₃COO)Ur₃][UO₂(CH₃COO)₃]. As the result of thermal analysis (polythermal and isothermal conditions) of bisdiacetato(dimethylacetamide)uranyl (VI) and the acetatoureauranyl(VI) triacetatodioxouranate(VI) it has been shown that the course of the thermal decomposition of the amide complexes of uranyl acetate, and also the composition of the oxide formed in this process are determined by the presence of the H atoms in the amide grouping which participate in the formation of hydrogen bonds in the compounds and lead to an increased mobility of the nitrogen atoms

[en] A series of chloronitroacetic acid (CNAA) esters was investigated and their PMR spectra studied in a pure state, and in solutions of CDCl₃, CO(CD₃)₂, and SO(CD₃)₂ at concentrations of from 5 to 50%. The effect of isotope exchange between the ester protons and deuteroacetone was observed. The kinetics of the deutero-exchange were studied. A possible mechanism of the deutero-exchange is discussed

[en] The properties of some Hg(I) chloride complexes, and in particular the effect of ligands on the delocalization of the unpaired electron is the subject of this report. The formation of HgX (X = Cl, Br, I, Cn, CNS) as an intermediate short-lived particle was postulated during the pulse radiolysis of aqueous solutions of HgX₂ salts. Results indicated that HgCl particles are formed during the γ-irradiation of aqueous H₂SO₄ and alcohol solutions of HgCl₂, while HgCl₄^3- particles are formed in the HCl solutions. Also the parameters of the EPR spectra and the optical characteristics of the particles were determined. The mechanisms of their formation are discussed

[en] In the radiolysis products of aerated and deaerated solutions of the 2-aminoethanethiosulfuric acid the authors have identified cystamine monoxide, cystamine, taurine, mercamine, the sulfate ion, the sulfite ion, and the dithionate ion. The yields of these products under different conditions have been determined. Results indicated that the sulfate ion is formed both from the divalent and the hexavalent sulfur atom of the 2-aminoethanethiosulfuric acid moelcule. A possible radiolysis mechanism is discussed