No abstract available

[en] Methods of ESR spectrometry of short-lived radical pairs in solutions, based on magnetic-spin effects in chemical reactions, are reviewed in this article. These methods also make use of such phenomena as quantum beats in reactions of radical pairs, the effects of resonance microwave radiation on the yield in reactions of radical pairs, and stimulated nuclear polarization that appears with microwave pumping. The methods are distinguished by high sensitivity. Examples are given of the application of these methods in studying the structure and reactions of radical pairs in solutions

[en] New method of determining the singlet-triplet ratio during recombination of ion-radical pairs, based on registration of quanta oscillations in fluorescence, is proposed. The quanta oscillations were studied for cyclic, linear and branched alkanes by various concentrations of diphenyl sulfide hole acceptor. ⁹⁰ Sr - ⁹⁰ Y with ∼ 5 μCi activity was the source of ionizing radiation. The study on fluorescence decay kinetics was carried out in magnetic fields of 9600, 4800 and 2400 Gs. The decay within the error limits is linear. The share of heminal pairs for the studied solvents varies within the frames of 0.35-0.54

[en] The fractions Θ^β and Θ^X of spin-correlated singlet radical-ion pairs in alkane solutions irradiated by β-particles and X-rays were got from experiments on magnetic field effects and quantum beats in recombination fluorescence. The ratio Θ^β/Θ^X values of 1.3-2.8 for the solvent series studied were found both from magnetic effect and quantum beats. The Monte Carlo calculations were made to explain the variations of Θ^β/Θ^X in different solvents. The high value of Θ^β/Θ^X = 2.8 for isooctane is probably due both to large separation between ions in pair and to high concentration of neutral radical in the spur

[en] Results of experimental and theoretical investigations are outlined systematically on electron tunnelling in chemical reactions. Mechanism of electron transport to great distances is shown to be characteristic to chemical compounds of a wide range. The function of tunnel reactions is discussed for various fields of chemistry, including radiation chemistry, electrochemistry, chemistry of solids, chemistry of surface and catalysis

[en] The main ways of investigation of initial radiation-chemical processes in liquid using magnetic effects are outlined. The method principles are considered. Block diagram for the installation used for observation of radioluminescence dependence on the magnetic field is presented. The luminescence is excitated by radioactive source (²²Na, ⁶⁰Co, ⁹⁰Sr) with the activity of several microcurie which is introduced into the liquid sample. Radiation-chemical applications of the investigation methods of initial process such as separation of recombination radioluminescence, fast reactions in a track, the part of heminal recombination of charges, reactions of recharging, identification of the couple ion-radicals, life time of the radical couple, management of radiation-chemical processes are considered in detail

[en] Principles of the method of optical detection of ESR spectra from radical-ion pairs in solutions are considered. Apparatus for detection of these spectra is described. Some examples of studying OD ESR spectra and reactions of radical-ion pairs arising in solutions under ionizing irradiation are discussed. (author)

No abstract available

No abstract available

[en] There is described low-field OD ESR method for studying radical-ion pairs under radiolysis. For the first time OD ESR spectra were obtained for some radical-ion pairs in polar solutions with ε till 45. It is shown, that the possibility of registration of low-field OD ESR spectra is mainly influenced by the reactivity of primary radical ions. Some constructive elements of low-field OD ESR spectrometer are also discussed. (author)