[en] Reactions of 1, 2 - naphthoquinone and 9, 10 - phenanthrenequinone with halides of 3 group elements (La, Sc, Y, In) are studied using the ESR method. The interaction of o-quinones with Lewis acids in THF proceeds according to the scheme of monoelectron transition and results in chelate complexes of o-semiquinones. The constants of splitting on the metals in similar paramagnetic complexes depend but slightly on the organic ligand, and the constants of splitting on the ligand protons correspond to the distribution of spin density in anion - radicals, obtained by monoelectron reduction of o-quinones

[en] When dimethylformamide solutions of 2,4,6-triphenylpyranyl radical (obtained from the dimer, which dissociates reversibly in DMFA) and trifluoroacetic acid are mixed under vacuum (10^-3 mm Hg), the mixture acquires a green color. The ESR spectra (recorded on a modified RE-1301 radiospectrometer) contain the radical-cation of 2,4,6-triphenyl-4H-pyran. A characteristic feature of the spectrum is the clearly defined doublet character resulting from the significant splitting at the 4H proton. Each component of the doublet consists of seven groups of hfs lines with intensity ratios of 1:4:7:8:7:4:1 (delocalization of the unpaired electron in the phenyl substituent at the p position). In addition, coupling of the unpaired electron with the 3,5 protons of the pyranyl fragment is observed

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[en] Reactions of E(C₂H₅)₃, where E=Al, Ga, In, Tl, with 3,5-di-tert. butylbenzoquinone-1,2 and 3,6-di-tert. butylbenzoquinone-1,2 were investigated. It has been established that the reactions proceed by the one-electron-transport mechanism. The formation of paramagnetic intermediates with a chelate structure is proved by EPR method

[en] By successive condensations based on pyrocatechol and acetone some oligopyrocatechols were prepared, and these were oxidized into the corresponding quinones. The ability of the oligoquinones to form paramagnetic metal complexes was investigated by the ESR. In the ESR spectra the structure of the aromatic ligands is not manifested to an appreciable extent. The electrochemical oxidation of sterically hindered oligopyrocatechols leads to the formation of the poly(radical cations), in the deprotonation of which the corresponding quinones are formed

[en] Using ESR spectroscopy the authors investigated the photolysis and radical composition of a plastic lubricant composed of polyethylene, perfluoroalkylpolyester 240, oleic acid, mineral oil, and benzophenone. The spectra are comprehensively analyzed. Hyperfine structure and spin trapping are given for the polyalkyl radicals. The photochemical modification of the lubricant leading to these radicals, and their reaction with oxygen, are determined to be responsible for the enhanced adhesion of the plasticizers to the polymer

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[en] Electrochemical and chemical oxidation of 1,3,1',3'-tetramethyl-2,3,2',3'-tetrahydro-2,2'-dipyriminyl takes place with rupture of the C-C bond in the initially formed cation radical. In the oxidation of the compound with aluminum chloride in nitrobenzene, ESR revealed a cation radical with an unresolved hyperfine structure. Oxidation of the dihydrodimer with nitrosonium perchlorate in nitrobenzene or nitromethane resulted in the same spectra. Cyclic volt-ampere diagrams are included