SovietRxiv · Open Access in English
Rediscovering the Soviet scientific archive, in English
25357 full-text translations 14926 English PDFs 22539 abstracts
Showing 50 of 4600 papers in Chemistry
This paper examines whether heats of combustion can provide thermochemical evidence for conjugation between a cyclopropane ring and phenyl substituents, a question relevant to debates over the bonding and anomalous properties of cyclopropane derivatives. Using bomb calorimetry, the authors determine…
This study examines phase equilibria in binary systems of thionaphthene with indene, indole, isoquinoline, 2-methylnaphthalene, 3-methylisoquinoline, and 2,6-dimethylnaphthalene, substances relevant to coal and petroleum refining products. Purified components and prepared mixtures were investigated …
This study examines the thermodynamic stability of divalent platinum tetrammine type complex ions containing ammonia, methylamine, ethylamine, or ethylenediamine ligands. Overall concentration instability constants were determined potentiometrically at constant ionic strength from platinum electrode…
The study examines the oxidation of beta-naphthol and selected dinaphthol derivatives by peroxide compounds, addressing uncertainty about radical intermediates in phenol and naphthol oxidation. Using electron paramagnetic resonance in organic solutions, the authors compare radicals formed from beta-…
This paper examines the oxymethylation of phosphine and methyl-substituted phosphines with paraformaldehyde under conditions that do not require hydrochloric acid or salts. The authors show that phosphine, methylphosphine, and dimethylphosphine react directly with paraformaldehyde to form trivalent …
Thin-layer chromatography on silica gel and gypsum plates is evaluated as a rapid micromethod for identifying and separating steroid intermediates used in the synthesis of corticosteroid analogs. The study tests cyclohexane and ethyl acetate solvent systems in varying ratios and compares visualizati…
This paper examines the synthesis of para-substituted styrenes and alpha-methylstyrenes containing silicon, germanium, and tin, compounds of interest as monomers for heat-resistant polymers. The authors apply the organomagnesium, Normant-Ramsden, route to prepare known trimethylsilyl and trimethylst…
This paper examines the applicability of Allen’s model of aqueous radiolysis, particularly the approximation that primary radiolysis products may be treated as uniformly distributed and described by homogeneous chemical kinetics. The authors use predicted intensity scaling relations, in which concen…
This study examines reactions of polyfluorinated nitrosoalkanes with compounds containing nucleophilic amino functions. It shows that primary aliphatic, alicyclic, and aromatic amines generally form polyfluorinated azo compounds under low-temperature or acidic conditions, while halogenated nitrosoal…
This study measures molecular transport properties of zirconium and hafnium tetrachloride vapors needed for developing separation methods for these compounds. Thermal conductivity was determined by a hot-wire method between 300 and 500 C, using hydrogen as a reference gas, and viscosity was measured…
This paper reports a simple synthetic route to quinolizidine derivatives, a class that includes several physiologically active alkaloids. The method starts from 2-methyl-2-(beta-cyanoethyl)dihydroresorcinol, which is hydrogenated over skeletal nickel in alkaline methanol and then treated with acetic…
This paper examines the equilibrium between tetrazole and azide forms of benzthiazolotetrazole using infrared spectroscopy in crystals, solutions, and melts. The spectra show that the crystalline compound has the tetrazole structure, while dissolution produces a reversible tetrazole to azide equilib…
This paper develops a quantum mechanical interpretation of radical polymerization at low temperatures, addressing why chain growth can proceed when repeated thermal activation of monomer addition would be inefficient. It compares ordinary energy-chain propagation, in which reaction heat is localized…
This study determines thermodynamic characteristics of niobium oxides in the niobium oxygen system, focusing on equilibria among Nb2O5, NbO2, NbO, and metallic niobium. Hydrogen reduction equilibria were measured by a circulation method at 1200 to 1550 °C, and electromotive force measurements were m…
This study examines the poorly characterized low temperature region of the uranium oxygen system, especially the structures and decomposition behavior of uranium peroxide hydrate and uranium heptoxide. Using oxygen 18 labels placed selectively in peroxide oxygen or hydration water, the authors follo…
This study examines phase equilibria in the titanium rich region of the titanium, zirconium, tin system, treated as the quasi-ternary system Ti, Ti3Sn, Zr. Seventy four alloys were prepared by crucibleless induction melting in purified helium, annealed at selected temperatures from 500 to 1560°C, qu…
This paper examines thermal-displacement chromatography as a preparative method for deep purification of organic gases, using propylene isolation as the main example. Mixtures containing propylene and impurities such as ethane, propane, ethylene, acetylene, sulfur compounds, water, and heavier hydro…
This study examines whether silver selenocyanate forms cationic complexes analogous to known silver halide complexes and whether nitrate and perchlorate counterions affect their formation. The authors measured the solubility of freshly prepared silver selenocyanate in concentrated aqueous silver nit…
This paper examines the quantitative influence of aromatic substituents on the polarographic reduction of azomethine compounds using the Hammett relationship. Phenylhydrazones, semicarbazones, and thiosemicarbazones of substituted aromatic aldehydes and acetophenones were studied in methanol water b…
This paper examines whether electric charges and potential jumps arising at phase boundaries can initiate polymerization in systems lacking conventional initiators or catalysts. The authors develop a kinetic argument that interfacial potentials may alter both the pre-exponential factor and activatio…
This paper examines the addition of dialkyl phosphorous acids to 3,3′-dimethoxy-diphenyl-4,4′-diisocyanate and diphenylmethane-4,4′-diisocyanate, extending earlier work on related diisocyanates. The reactions were carried out in the presence of small amounts of sodium or sodium alcoholate, and the a…
The study examines how steric hindrance affects pressure dependence in Menschutkin reactions, using nitrobenzene as a solvent to reduce solvation volume effects. Rate constants were measured under pressure for reactions of 2,6-lutidine with ethyl and isopropyl iodide, and of gamma-picoline with ethy…
This study compares the kinetics and energetics of converting methane, ethane, propane, ethylene, and propylene to acetylene in glow and high-voltage arc discharges under static conditions. Experiments measured product composition, hydrocarbon conversion, apparent first-order decomposition constants…
This study investigates the preparation of acyloxy derivatives of cobalt, nickel, and manganese by exchange reactions between metal acetylacetonates and carboxylic acids. Cobalt and nickel diacetylacetonates and manganese triacetylacetonate were reacted with saturated and unsaturated dibasic acids, …
This study examines how the limiting explosion pressure of gaseous hydrazoic acid depends on the power of a spark pulse, addressing earlier views that the pressure reaches a lower boundary beyond which increased spark energy has no effect. Experiments in a spherical glass vessel with a central spark…
This study examines the formation of carbonyl compounds and acids during the emulsion oxidation of isopropylbenzene, with particular attention to the effects of inhibition by beta-naphthol. Oxidation experiments in a weakly alkaline emulsion showed that addition of the inhibitor stopped peroxide acc…
This paper investigates synthetic routes to polymethine dyes in which phosphorus replaces one or both terminal nitrogen atoms of conventional cyanine chromophores. The authors show that phosphonium salts with active methylene groups condense with p-dimethylaminobenzaldehyde to give phosphostyryl dye…
This paper investigates the ion-exchange separation of rubidium and cesium using ammonium phosphotungstate, motivated by the need for selective, radiation-stable inorganic exchangers for chemically similar heavy alkali metals. The authors prepared a low-resistance chromatographic column by depositin…
This paper describes the application of N,N′-dicyclohexylcarbodiimide to the synthesis of S-aminoacyl derivatives of cysteine peptides, considered as thiodepsipeptides because they contain a thioester linkage. The authors condense ethyl N-carbobenzoxy-L-cysteinylglycinate with carbobenzoxy-protected…
This paper examines why benzene interacts more strongly with hydroxylated oxide surfaces than would be expected from comparisons with nonpolar hydrocarbons. The authors model the interaction of a benzene molecule with an OH dipole using molecular orbitals that include both delocalized pi bonds and l…
This study examines the catalytic hydrogenation and ring opening of unsymmetrical alpha, beta, and gamma organic oxides in a flow system at 50 atm hydrogen pressure. Propylene oxide, alpha-methyltrimethylene oxide, alpha-methyltetrahydrofuran, and related substrates were hydrogenated over skeletal C…
The paper reports low-temperature spectroscopic observations of fine structure in the absorption and fluorescence spectra of metal-free phthalocyanine, magnesium phthalocyanine, and protoporphyrin in frozen normal paraffin solutions at 77 K, using Shpol’skii-type conditions. Photographic spectra sho…
This study tests whether metallic platinum exchanges with complex ions of divalent platinum in aqueous solution, a hypothesis proposed to explain the nonindifferent behavior of platinum electrodes in such media. Irradiated platinum foil containing Pt-197 was shaken with chloride and platinum complex…
This paper examines the mechanism by which imido esters rearrange to substituted amides in reactions with alkyl halides, a process previously proposed to involve unstable addition intermediates. The authors investigate iodide salts of aryl benzimido esters and show that, although heating alone does …
The paper reports a new synthesis of 19-nor-11-deoxycorticosterone acetate from strophanthidin, aiming to obtain a product with the configuration corresponding to natural 11-deoxycorticosterone. The authors describe conversion of the strophanthidin lactone ring to an alpha-ketol side chain by ozoniz…
This paper examines the synthesis of polymers containing charged heteroatoms in the main macromolecular chain, termed onium polymers, using 4-chloropyridine as a model monomer. Heating or storing purified 4-chloropyridine produced polychloropyridine, whose elemental composition, titratable ionic chl…
This paper develops a theoretical treatment of the coagulating action of mixtures of electrolytes on weakly charged lyophobic sols, focusing on the role of counterion adsorption. Using a Langmuir adsorption model, a linear relation between adsorption and the potential at the adsorption layer boundar…
This study examines the mechanism of radiation oxidation of benzene in aqueous solution, testing whether products arise through hydrogen abstraction to phenyl radicals or through addition of water radiolysis radicals to the benzene ring. Benzene was irradiated with cobalt-60 gamma radiation in heavy…
This study examines the mechanism of thermal decomposition of organic percarbonates in solution, focusing on the interaction of alkoxy radicals with solvents. Using the radical scavenger DPPH, carbon 14 labeling, deuterated isopropyl alcohol, and product analysis, the authors compare decomposition i…
This paper describes the synthesis of organotin and organolead esters of biologically significant nitrogen-containing acids, including alpha-alanine, p-aminobenzoic, nicotinic, isocinchomeronic, orotic, and uracilacetic acids. The authors prepare these compounds through reactions of organotin or org…
This paper describes a total synthesis of dl-8-isoestrone from the previously prepared methyl ether of 8,9-dehydro-D-homoestrone. The route proceeds through catalytic hydrogenation to the methyl ether of D-homo-8-isoestrone, condensation with furfural, alkaline hydrogen peroxide oxidation to a dicar…
This study examines the contact transformations of cyclooctane over a nickel on kieselguhr catalyst in a hydrogen stream at 200 and 250 degrees C. The reaction products were separated by fractionation and identified mainly by Raman spectroscopy, allowing comparison of conversion pathways at the two …
This study examines the hydration and adsorption properties of anatase titanium dioxide surfaces subjected to different thermal treatments. Using volumetric adsorption measurements of water and nitrogen vapor, BET surface area determination, and quantification of water released on ignition, the auth…
This study determines diffusion coefficients of several metal and network-forming ions in molten aluminate and silicate slags using concentration polarization during cathodic deposition and oscillographic measurement of the transition time to limiting concentration at the cathode. Measurements for F…
This study examines how radioactive calcium-45 affects the catalytic dehydration of cyclohexanol over mixed magnesium sulfate and calcium chloride catalysts, in comparison with earlier results for sulfur-35. Catalysts containing varied proportions of calcium chloride were prepared with and without r…
This paper describes the use of neutron activation analysis for determining tungsten in minerals and beneficiation products, especially scheelite concentrates. The authors irradiate samples with a polonium beryllium neutron source, measure beta activity from the induced isotope W187, and use calibra…
This paper examines how the dispersity of solid emulsifier particles relates to the stability and droplet size of oil-in-water emulsions. Using a modified shear-measurement apparatus, the authors measured the limiting two-dimensional shear stress of protective interfacial particle layers and compare…
This paper examines how solution concentration affects the conformation of polymethacrylic acid chains in water, motivated by a reversal in the temperature dependence of viscosity between dilute and concentrated solutions. Viscosity measurements using a rotational viscometer at concentrations of 6, …
This study examines the low-temperature alkylation of naphthalene with propylene at atmospheric pressure over an industrial aluminosilicate catalyst, with attention to minimizing side reactions and determining the isomeric composition of the products. Experiments varied temperature and naphthalene t…
This study examines the redox potential of the Ti2+/Ti3+ system and the equilibrium constant for the reaction between trivalent titanium and metallic titanium in molten chloride salts. The authors compare hydrogen potentiometric titration with titration using metallic titanium in molten sodium and p…
