E. D. Skakovskii

13C NMR Study of the Structure of Products Formed in Base Hydrolysis of Nitron D Polyacrylonitrile Fiber

The composition and structure of the products formed in base hydrolysis of Nitron D polyacrylonitrile fiber were studied by 13C NMR.

Nonequilibrium Polarization of Nuclei In Photolysis of Solid Cyclohexane Solutions of Diacyl Peroxides and Ketones

The effects of the polarization of nuclei in photolysis of solid solutions of peroxides of acetylpropionyl and acetylbenzoyl, acetone, acetone‐d6, methyl ethyl ketone, cyclopentane, and cyclohexanone in cyclohexane and cyclohexane‐d12 are investigated. The role of the triplet states of the compounds absorbing light and of the radicals formed of them in creation of nonequilibrium polarization of the 1H and 13C nuclei in irradiation of these solutions has been evaluated.

Thermolysis of Methanolic Solutions of Acetyl Propionyl Peroxide

Kinetic measurements by 1H NMR spectroscopy and chemically induced dynamic nuclear polarization (CIDNP) effects were used to study thermolysis of solutions of acetyl propionyl peroxide in methanol-d4. It is found that the thermolysis may occur both by radical and by nonradical mechanisms. A scheme of the thermolysis is proposed. Parameters of the Arrhenius equation for the rate constants of the decomposition of the peroxide and the decarboxylation of acyloxyl radicals are obtained.

Lifetime of acyloxy radicals produced by decomposition of acetylpropionyl peroxide

The authors consider thermolysis of 0.5M solutions of acetylpropionyl peroxide in CCl4 at 333 and 343 K as well as photolysis of 0.5M solutions of acetylpropinyl piroxide in CCl4 at 253–333 K and photolysis of methanol solutions of acetylpropionyl peroxide with added 1 m CCl4 at temperatures of 193–253 K. The effects of chemical nuclear polarization and reaction yields were analyzed to determine the decarboxylation rate constants of acyloxy radicals that were produced by thermolysis and photolysis of acetylplpropionyl peroxide.

1H and 13C NMR spectroscopic studies of hexane-extractable lipids from soils under shelterbelts of different age and composition of plants

Comparative study of the composition of lipids extracted with n-hexane from soils under shelterbelts of different age and composition of plants and adjoining cultivated fields in agrolandscape has been carried out with the application of (1)Н and (13)С NMR spectroscopy. The lipid content correlates with the organic carbon content in soils and is the highest in the soil under the 200-years old shelterbelt. The data received indicate that hexane-extractable lipids from the soil under the 200-years old shelterbelt have undergone the most significant biochemical and chemical transformations (oxidation, hydrolysis, polymerization) with the accumulation of resistant compounds and destruction of esters of o-phthalic acid as anthropogenic contaminants compared to the lipids from the soil under the 14-years old shelterbelt and soils of adjoining arable fields.

Interaction of carboxylated polyacrylamide with chromium(III) acetate: 13C NMR study of mechanism

The interaction of chromium(III) acetate with poly(acrylamide-co-acrylic acid) in aqueous medium leads to formation of three-dimensional network of crosslinked macromolecules. Formation of the complex between chromium(III) cation and carboxylate groups is a driving force of the interaction. Depending on the reagents ratio, the complex contains two or three carboxylate groups. The amide units are not involved in any specific interaction with the cation.

Aqueous adhesives based on dextrin-containing polyacrylate composites

Rheological and adhesion characteristics of water-soluble adhesive composites based on copolymer of acrylamide with sodium acrylate and corn dextrin were studied. The optimum composition of these composites in their use as label adhesives was determined.

Photolysis of Solutions of 3-tert-Butylperoxy-3-methyl-1-butyne

Photolysis of solutions of 3-tert-butyl-3-methyl-1-butyne in CD3OD and C6D12 was studied by means of 1HNMR spectroscopy, chemical nuclear polarization of the reaction products in the range 213- 333 K, and kinetic measurements. It is shown that 3-tert-butyl-3-methyl-1-butyne decomposes primarily from a singlet electronic state. A scheme is proposed of the most probable reactions involving the radicals formed and solvent molecules. It is found that secondary processes play an important role in the initiation of the chemical nuclear polarization and the photolysis mechanism.

Analysis of the Mechanism of Photolysis of Methanol-d4 Solutions of Acetylpropionyl Peroxide with the Use of Chemically Induced Dynamic Nuclear Polarization

On the basis of the effects of chemically induced dynamic nuclear polarization of 1H and 13C and the yields of reaction products, the photolysis of methanol-d4 solutions of acetylpropionyl peroxide is investigated within the temperature interval 193–333 K. Polarization of all the protons of ethylethanoate is detected; it is shown that the latter is formed in several chemical reactions. The role of different excited states of the peroxide in the mechanism of its photolysis is discussed.

Photochemical reactions of some mono- and diketo derivatives of adamantane in various solvents

Adamantanes are photoactive in the presence of CCl4 and CDCl3. The mechanism of their photolysis, involving the formation of singlet or triplet excited donor-acceptor complexes has been suggested.