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
The paper investigates the synthesis of pyrylium salts through acid-catalyzed condensation of oxymethylenecyclohexanone with a range of ketones, including acetone, acetophenone derivatives, heteroaryl methyl ketones, cycloalkanones, and tetralone. The authors show that treatment in acetic acid with …
This study examines the role of dislocations in the thermal decomposition of ammonium perchlorate crystals, motivated by earlier observations that decomposition begins at localized centers and develops anisotropically. Single crystals were grown from purified aqueous solution, etched in ethyl alcoho…
This study determines thermodynamic properties of solid iron silicon alloys over 600 to 800°C using electromotive force measurements of a galvanic cell involving pure iron, molten iodide electrolyte, and Fe Si alloys. From linear temperature dependences of the cell emf, the authors derive partial ch…
This study examines whether organic polymers with conjugated bond systems can photosensitize the oxidation of ascorbic acid by oxygen, a behavior expected from their semiconducting properties. Using Warburg-Barkroft micromanometry, the authors measured oxygen uptake in aqueous ascorbic acid suspensi…
This study examines the formation of thorium orthophosphates and related phosphate complexes in aqueous systems, addressing whether compounds previously obtained mainly by fusion can be isolated from solution. Equimolar systems containing thorium nitrate with phosphoric acid, sodium dihydrogen phosp…
This paper examines the instability of alkoxyphosphonium salts and tests the hypothesis that delocalization of the onium charge through nitrogen-containing substituents can increase their stability. The authors synthesize several alkoxyaminophosphonium and related phosphazacyanine salts from phosphi…
This study investigates the solution structures and tautomeric equilibria of phenylmercury derivatives of substituted 2-phenylsulfonylaminopyridines, prepared by reaction with phenylmercury hydroxide. Cleavage reactions and salt formation behavior indicate bonding of the phenylmercury group to nitro…
The study examines the reaction of phosgene with 1-alkyldihydro-(1,2)-quinolones-(2), a class of cyclic amides for which this interaction had been little investigated. Experiments show that these substrates react readily at room temperature to form chloroalkylates of 2-chloroquinolines, identifying …
This study examines the mechanism by which acetylene and acetaldehyde interact with mercury ions in sulfuric acid during the Kucherov hydration of acetylene to acetaldehyde, focusing on the cause of mercury catalyst deactivation. Using a flow apparatus and a stabilized mercury catalyst system withou…
This study examines whether dienophile activity in Diels-Alder diene synthesis correlates with the mean NMR chemical shift of β-hydrogen atoms in vinyl and isopropenyl dienophiles, on the assumption that both reflect electron density at the double bond. Rate constants were measured spectrophotometri…
This study examines hydration and crystallization in sodium metasilicate using calorimetry, with attention to how condensed silicate anions affect behavior typical of inorganic binders. Measurements of heat evolution during formation of supersaturated solutions and crystallization of Na2H2SiO4·8H2O …
This paper investigates the mechanism by which cobalt(II) caprylate catalyzes urethane formation from phenyl isocyanate and n-butyl alcohol. Using dilatometric kinetic measurements and electronic absorption spectroscopy under vacuum, the authors examine how catalyst concentration, reagent ratios, re…
This paper analyzes electron paramagnetic resonance spectra of individual nitroxyl tri- and tetraradicals to determine how multiple unpaired spins participate in intramolecular exchange. By comparing spectra in different solvents and at different temperatures, the authors show that exchange can invo…
This study examines heterogeneous equilibria in quaternary systems containing potassium, rubidium, or cesium halides with antimony(III) chlorides or bromides in aqueous hydrochloric or hydrobromic acid. Solubilities were measured isothermally at 25 degrees C at several fixed acid concentrations, and…
This study examines the products formed in the reaction of alpha-(2-chloroethyl)-beta-chlorocrotonaldehyde with hydrochlorides of aromatic amines, focusing on the structure of Schiff bases of N-arylpyrrolines. The authors prepared a series of derivatives, separated principal and minor products by ch…
This study examines why phenol yields increase during radiolysis of aerated sulfuric acid aqueous benzene solutions containing ferrous ions. Using cobalt-60 gamma radiation and 0.9 MeV electrons, the authors measured the formation of ferric ions, phenol, and muconic dialdehyde as functions of ferrou…
This study examines the thermodynamics of hydration of KU-2 sulfonic cation-exchange resin in H, K, Na, and Ca forms, using samples with 4% and 20% divinylbenzene cross-linking. Water vapor sorption isotherms, heats of wetting, and derived thermodynamic functions were used to estimate monolayer capa…
This paper develops a simplified kinetic description for irreversible reactions occurring in polymer chains when the rate constant for a unit depends on whether zero, one, or two neighboring units have already reacted. Using a sequence-based representation of copolymer chain structure, the author re…
This addendum clarifies Delone’s method for setting a crystal lattice by giving explicit rules for expressing the vectors of a crystallographic Bravais frame in terms of vectors obtained from an initial fundamental frame through Selling reduction. It specifies corrections to the reduction procedure,…
This study examines the role of water in the stereospecific polymerization of butadiene in aqueous emulsion initiated by rhodium chloride, a reaction known to yield highly trans-1,4-polybutadiene but with an uncertain mechanism. Using tritiated water as an isotopic label, the authors measured radioa…
This study examines how common inhibitors affect ethylene polymerization on supported chromium oxide catalysts, focusing on pentavalent chromium ions identified as active centers. Using electron paramagnetic resonance spectra of activated chromaluminosilicate catalysts treated with water, butanol, b…
Phase equilibria in the sodium borohydride, hydrazine system were investigated by differential thermal analysis over the range from minus 120 to 80 degrees C and from 0 to 85.5 wt.% sodium borohydride. The study identifies four solvated compounds, NaBH4·2N2H4, 2NaBH4·N2H4, NaBH4·N2H4, and NaBH4·6N2H…
This study examines the vapor-phase molecular structure of N-dimethylaniline, with particular attention to the configuration of the trivalent nitrogen atom and the rotational arrangement of the dimethylamino group relative to the phenyl ring. Electron diffraction patterns were recorded at two camera…
This paper explores the use of the Wittig reaction as a route to C-substituted carbohydrate derivatives that are difficult to obtain by organomagnesium methods, especially when functionalized aglycone fragments are required. Acetylated aldehydo forms of D-glucose, D-galactose, and D-mannose were con…
Polymorphic transformations in octahydroanthracene, orcin, and carbon tetrabromide are examined to determine whether the mechanism previously observed in n-dichlorobenzene is more general for organic molecular crystals. Using Laue X-ray photography and optical polarizing microscopy under controlled …
This paper examines diffusion in polyisobutylene, solvent systems, with emphasis on relating interdiffusion, one-sided diffusion, and self-diffusion coefficients for low-molecular solvents in a polymer medium. Using an interference micromethod, concentration profiles were measured for polyisobutylen…
This study examines the basicity of phosphotungstic and silicotungstic heteropoly compounds by infrared spectroscopy, with particular attention to spectral evidence for oxonium ions and strongly hydrogen-bonded water. The authors prepared several acids and sodium or barium salts, recorded spectra in…
This paper analyzes the experimental entropy of activation for hydrogenation of carbon monoxide and carbon dioxide to methane on a nickel containing catalyst under conditions where side processes are negligible. Using transition state theory and reported kinetic data, the authors compare activation …
This paper examines why anionic forms of cyclopentene-4-dione-1,3 and indandione-1,3 derivatives show unusually deep coloration and long-wavelength absorption compared with typical beta-diketone anions. Using LCAO molecular orbital calculations in the Hückel approximation, the authors compare transi…
This study examines adsorption and chemisorption of vapors of methanol, ethanol, diethyl ether, acetone, acetaldehyde, and acetic acid on KSK silica gel and alumina gel, with relevance to porous-body surface chemistry, catalysis, and purification processes. Adsorption and desorption isotherms were m…
This paper investigates the formation of anomalous liquid columns during vapor condensation in quartz capillaries, addressing whether their reduced vapor pressure and increased viscosity can be attributed to leaching from glass walls. Using a controlled chamber with adjustable air pressure, vapor sa…
This study investigates the carbohydrate chains of the ginseng triterpene glycosides panaxosides D, E, and F, using the proposed native genin structure as the basis for analytical calculations. Complete methylation followed by hydrolysis, chromatographic identification of methylated sugars, periodat…
This paper examines whether acid,base catalysis can accelerate liquid phase radical reactions that normally require high activation energies, using reactions of stable nitroxide radicals with substituted p-phenylenediamines as a model system. Experiments in acetic acid,acetone mixtures, monitored by…
Single crystals of a new potassium europium diorthosilicate, K3Eu(Si2O7), were synthesized from solution in a KF melt by slow programmed cooling and examined by optical, goniometric, infrared spectroscopic, chemical, and X-ray methods. The crystals are hexagonal, optically positive and uniaxial, wit…
This paper examines quantitative relationships between the structure of neutral organophosphorus extractants and their ability to extract actinide nitrates, using substituent sigma constants at the phosphorus atom as electronic parameters. Effective extraction constants for uranyl nitrate in benzene…
This paper examines the classification of stable geometric elements, or singular stars, in septenary reciprocal salt systems and their use in predicting eutectic parageneses and exchange reaction directions. Using index tables and singular star schemes, the authors compare known type 16C systems wit…
The paper investigates acid protolysis of cis- and trans-beta-chlorovinylmercury chlorides by HCl and DCl in absolute dioxane and dimethyl sulfoxide, focusing on reaction mechanism, isotope effects, and stereochemical course. Kinetic measurements show second-order behavior in dioxane, consistent wit…
The study examines 1,3-dipolar cycloaddition reactions of 3-nitroisoxazoline N-oxides with alkenes and identifies the resulting bicyclic nitroisoxazolidizine products. Reaction of the parent N-oxide with ethylene afforded 8-nitroisoxazolidizine in high yield, with structural assignment supported by …
This paper examines how the stereochemical heterogeneity of a heterogeneous catalyst affects the polymerization rates and optical properties of propylene oxide enantiomers and racemic mixtures. The authors develop three limiting mechanistic cases for stereospecific chain growth, then test them by po…
A method is presented for determining nonradiative ligand to rare-earth energy-transfer rate constants in chelate complexes, using competition between intramolecular transfer to the rare-earth ion and intermolecular triplet-triplet quenching by added organic acceptors. Measurements in toluene soluti…
This paper examines the gas phase preparation of boron phosphide single crystals using reversible chemical transport with group VI carrier elements. Experiments varied the temperature gradient between source and crystallization zones and the crystallization temperature, showing that smaller gradient…
The study examines the preparation of ethyl alpha-nitroacrylate from ethyl nitroacetate and formaldehyde, a route of interest for alpha-amino acid synthesis but previously hindered by resin formation and instability of intermediates. By carrying out the condensation at low temperature with aqueous f…
The paper reports a single-crystal X-ray determination of the crystal structure of gamma-Rb2BeF4, motivated by uncertainty over structural analogies between alkali orthofluoroberyllates and related silicates or sulfates. Using goniometric layer-line photographs, Patterson projections, and heavy-atom…
This paper examines the selective hydrogenation of the dienone group in 6-methylheptadien-3,5-one-2 over nickel and cobalt catalysts, focusing on how catalyst modification changes the direction of hydrogen addition. Experiments with supported nickel catalysts, pyridine as a displacing additive, and …
This paper addresses the dependence of radioactive fallout fractionation on particle size for products of nuclear explosions, especially large spherical particles formed in surface bursts. It develops a method for estimating fractionation coefficients by separating activity into volume and surface c…
The paper investigates oxygen ionization and reduction processes on silver in alkaline solution using a rotating silver disk electrode with a platinum ring, combined with triangular potential pulses. Ring-current measurements show that hydrogen peroxide is formed as an intermediate during molecular …
This study examines the polymerization of vinyl chloride initiated by systems formed from carbon tetrachloride and individual organotitanium compounds, motivated by prior evidence that titanium halides influence radical initiation. Experiments compared tetravalent, mixed cyclopentadienyl alkyl or ar…
This paper reports a gas-phase electron diffraction study of phenylcyclopropane, addressing the molecular geometry and the rotational isomerism about the bond connecting the benzene and cyclopropane rings. Experimental scattering and radial distribution curves were compared with theoretical curves f…
This study examines the mechanism of methylcyclohexane dehydrogenation to toluene over an alumina, chromia catalyst, extending earlier tracer studies of cyclohexane dehydrogenation. Flow reactor experiments combined chromatographic product analysis with additions of radiocarbon-labeled methylcyclohe…
