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 study examines structural changes in polyacrylonitrile during vacuum pyrolysis using nuclear magnetic resonance measurements of the second moment of the proton resonance line over a wide temperature range. Samples pyrolyzed at 210 and 320 °C for different times were compared with untreated poly…
This paper develops and applies a method for calculating adsorption parameters of surface-active organic substances on a mercury electrode from impedance measurements, using the diffusion-limited adsorption theory of Frumkin and Melik-Gaikazyan. The authors derive working formulas for the concentrat…
This study examines charge-transfer complex formation between ferrocene as an electron donor and trinitrobenzene derivatives, including sym-trinitrobenzene, picric acid, and picryl chloride, as acceptors. Spectrophotometric measurements in 1,2-dichloroethane and chloroform, analyzed by Job’s method …
This paper examines the ambident reactivity of the sodium diethyl thiophosphate anion toward the strong electrophilic alkylating agent triethyloxonium borofluoride, in contrast to the usual sulfur alkylation observed with alkyl halides and related reagents. Alkylation in chloroform was followed by t…
This study examines whether four-coordinate intracomplex chelates of salicylaldimine type can be obtained with two different ligands bound to the same metal center. Attempts using Schiff bases with chemically different amine residues gave X-ray evidence for mechanical mixtures of chelates containing…
This paper reports measurements of the detonation velocity of liquid hydrazoic acid and selected aqueous solutions, motivated by the value of hydrazoic acid as a comparatively simple explosive system for studies of high pressure detonation products. The authors prepared hydrazoic acid from sodium az…
Methylcyclononane was studied under dehydrogenation catalysis to determine how a methyl substituent affects transformations of the nine-membered cyclane ring. The hydrocarbon was synthesized and passed over an iron, platinum on carbon catalyst at 310° C, and the liquid products were separated and id…
This study investigates the state and mobility of water adsorbed on cation-substituted montmorillonite using proton nuclear magnetic resonance. Water vapor adsorption was measured for Ca-, Li-, and K-montmorillonite, and NMR line widths and relaxation times were determined as functions of water cont…
The study examines reactions of acetyl, benzoyl, and p-toluyl derivatives of cyclopentadienylmanganese tricarbonyl with Normant’s reagent, vinylmagnesium bromide, in tetrahydrofuran. The reactions afforded the corresponding vinyl-substituted tertiary alcohols in moderate to high yields, with product…
The paper examines acid-promoted isomerization of tertiary beta-acetylenic alcohols into the corresponding alpha,beta-unsaturated ketones, with emphasis on 2-hydroxypent-4-yn-2-yl-2-cyclopentadienylmanganese tricarbonyl. Heating with potassium bisulfate gives a crystalline enone complex assigned as …
This study examines the addition of thiobenzoic acid to polychloroprene in order to assess how the electronegative chlorine atom affects the reactivity of double bonds in diene polymers. Kinetic experiments were conducted in benzene, xylene, and chlorobenzene under argon, with varying temperature, r…
This paper investigates whether glass electrodes made from sodium silicate glasses containing iron oxides can respond to the oxidation potential of a solution, unlike ordinary glass electrodes with purely ionic conductivity. The authors compare glasses melted under oxidizing conditions with low-resi…
This study examines the aglycone formed from panaxoside A, a glycoside isolated from ginseng roots, and compares its hydrolysis behavior with that of related panaxosides. Acid hydrolysis, chromatographic separation, elemental and functional group analyses, infrared, ultraviolet, nuclear magnetic res…
The study examines acid-catalyzed reactions of furan alcohols bearing hydroxyl groups in the gamma and epsilon positions relative to the furan ring with alpha,beta-unsaturated aldehydes and ketones, particularly substrates containing alkyl substituents at the double bond. Primary and secondary furyl…
This study examines how solution pH affects hydrogen adsorption on platinized platinum, a question relevant to the kinetics and mechanism of liquid phase hydrogenation. Using the charging curve method, experiments were conducted in sulfate solutions with constant sulfate ion concentration and in Bri…
This paper examines quantitative correlations between reaction rates and conjugation-related properties for catalytic hydrogenation and related hydrogen-transfer reactions. By comparing published kinetic data, the authors argue that many heterogeneous hydrogenations of aromatic, conjugated, and quin…
This paper examines whether dissociation of large molecular ions formed by electron impact proceeds by a rapid local mechanism or by a slower statistical redistribution of excitation. The authors develop a mass-spectrometric method based on measuring anisotropy in the angular, or velocity-projection…
This study examines equilibrium conditions and hydrogen reduction mechanisms for spinel solid solutions in the Fe, Cr, O system at 1000 C over the composition range FeCr2-xFexO4. Solid solutions were prepared by ceramic synthesis and reduction, then characterized by X-ray diffraction, while gas phas…
The paper examines the addition of ethylenimine and, for comparison, diethylamine to alkenylsilanes as a route to organosilicon compounds containing an ethylenimine heterocycle in the hydrocarbon radical. A series of vinyl, allyl, butenyl, styryl, and hydrocarbon analog substrates was tested with so…
This study examines the so-called beta effect in beta-alkenylgermanes by measuring Raman intensities of the carbon-carbon double-bond vibration as a function of molecular geometry. Several alkenylgermanes were synthesized, including beta-(trichlorogermyl)cyclopentene and bis(germyl)-substituted bute…
This study applies diffusion measurements to determine the state of radioactive isotopes in extremely dilute aqueous solutions, where diffusing particles can be treated as moving independently and complications from concentrated solutions are reduced. Using open capillary and related methods with co…
This paper describes the synthesis of alkaloid, amino acid, peptide, and heterocyclic acid derivatives intended as possible complexes of medicinal compounds with modified pharmacological properties. Using mixed anhydride methods with carbobenzoxy protecting groups, the authors prepared a series of c…
This paper examines the mechanism of acetylene cyclotrimerization on Ziegler-type organometallic catalysts, focusing on systems based on titanium compounds and aluminum alkyls. Experimental comparisons of substituted acetylenes, mixed trimerizations, solvent effects, electron-donor additives, and va…
This study examines the reactivity of hydrocarbons and related compounds in the initial hydrogen abstraction step of polymer formation by polyrecombination. Reactivity toward tert-butoxy radicals was estimated from tert-butyl alcohol and acetone ratios formed during decomposition of tert-butyl perox…
This study examines phase equilibria and extraction behavior in the quaternary system lanthanum nitrate, ammonium nitrate, water, and tributyl phosphate at 25 degrees C. Using the extraction-ray method, equilibrium analysis, complexometric determination of lanthanum, radiotracer measurements with La…
This paper develops chemiluminescent methods for determining absolute termination rate constants of peroxide radicals during low-temperature liquid-phase hydrocarbon oxidation. Using the proportionality between activated chemiluminescence intensity and the square of the peroxide radical concentratio…
This paper examines the solubility of uranyl nitrate and water in tributyl phosphate from 0 to 100 degrees Celsius, addressing discrepancies in earlier reports on the composition and temperature dependence of uranyl nitrate solutions in this solvent. Equilibria were established in thermostatted thre…
This paper examines why the catalytic activity of KU-2 cation-exchange resin declines during alkylation of phenol and technical cresol mixtures with propylene trimer. The authors compare possible causes, including polymer degradation, chemical reaction of sulfonic acid groups with reactants, and ads…
This paper reports an electron diffraction investigation of the molecular structure of alpha pinene, with particular attention to the arrangement of key carbon atoms, valence angles, and the geometry of the cyclobutane ring. Diffraction patterns of alpha pinene vapor were measured at 40 and 60 kV an…
This study examines how hydrogen content, structure, and magnetic properties relate to the activity of nickel formate catalysts used for fat hydrogenation. Catalysts prepared by thermal decomposition of nickel formate in sunflower oil under hydrogen or nitrogen, and subsequently dehydrogenated or si…
This study examines Sn-119 Mössbauer resonance absorption spectra of asymmetric tetravalent organotin compounds, especially those containing electron-donor substituents, to assess how substituent character affects electric-field gradients at the tin nucleus. Measurements at liquid-nitrogen temperatu…
This paper examines the cleavage of siloxane bonds by thionyl chloride under ultrasonic irradiation, using hexaalkyldisiloxanes and chrysotile asbestos as substrates. Sonication at about 20 kHz converted hexamethyldisiloxane to trimethylchlorosilane in 27.5% yield, while hexaethyldisiloxane reacted …
This study examines the electronic structure and bonding of alpha-thiopicolinanilide Cu(II), a monomeric analogue of chelate polymers, using electron paramagnetic resonance spectra in polycrystalline form and in benzene, dioxane, and chloroform solutions. The polycrystalline sample showed an anisotr…
This paper examines ion adsorption at the mercury, aqueous electrolyte interface in concentrated KCl and CsCl solutions, where dilute-solution double-layer approximations and Grahame’s assumption of nonspecific cation adsorption may fail. Electrocapillary measurements with a Gouy electrometer, combi…
This paper examines regularities in ionic polymerization by analogy with known inhibition effects in radical copolymerization, where small amounts of a more reactive monomer can retard polymerization of a less reactive one. The authors analyze cationic and coordination-cationic systems in terms of t…
This paper reports the synthesis and characterization of four mixed binuclear carbonyl derivatives containing cyclopentadienyl tricarbonyl molybdenum or tungsten bonded to manganese or rhenium pentacarbonyl fragments. The compounds were prepared by reacting sodium salts of cyclopentadienyl tricarbon…
This paper develops a mathematical theory for combustion of condensed systems in which gasification is accompanied by heat release from a first order reaction in the condensed phase, rather than the zero order reaction assumed in earlier models. The authors formulate the steady boundary value proble…
The study examines how ring substituents affect the electrophilic bimolecular substitution reaction of substituted benzylmercury halides with iodine in the presence of cadmium iodide. Kinetic measurements in methanol and dimethylformamide show second-order behavior, but the substituent effects do no…
This study examines the reaction of thionyl chloride with kaolin and chrysotile asbestos as a route to chlorine-containing layered silicate derivatives bearing reactive Si-Cl bonds. Experiments compared ordinary reflux conditions, catalytic addition of stannic chloride, and ultraviolet irradiation, …
This study examines the physicochemical properties of thixotropic and filled iodine, polyvinyl alcohol gels, with attention to how polyvinyl alcohol structure, iodine content, boric acid additives, thermal treatment, and solution aging affect gel formation and mechanical behavior. Using viscosity me…
The study examines the reaction of diazoacetic ester with the organosilicon tetraene tetraallylsilane, addressing the limited knowledge of carbene addition to polyene systems. Using copper sulfate catalysis at 100 to 110° with excess unsaturated substrate, carbethoxycarbene was added stepwise to the…
The paper examines quasitautomeric transformations of aminotriphenylcarbinols in sulfuric acid, where increasing acid concentration shifts equilibria from colorless ammonium ions to conjugated carbonium ions and, at higher acidity, to protonated carbonium salt forms. Treating the system as a triple …
This paper examines acetylated glycosyl perchlorates of glucose, galactose, and xylose as reactive intermediates for carbohydrate synthesis. The authors prepare these unstable, explosive syrup-like perchlorates from acetohalogenoses and silver perchlorate, then react them with several alcohols in th…
This paper investigates resonance properties in electrochemical self-oscillating systems, focusing on a copper anode in phosphoric acid whose stationary polarization curve lacks a falling segment but whose dynamic polarization curve can show a negative slope dependent on signal frequency. Using a tw…
This paper examines how the molecular weight of polyoxymethylene formed by cationic polymerization of trioxane depends on monomer concentration and reaction conversion. Trioxane was polymerized in methylene chloride and nitrobenzene at 30 degrees Celsius using tin tetrachloride, and polymer molecula…
This study examines how oxidized forms of oleic acid interact with the surfaces of limonite, ferruginized quartz, ferrimolybdite, and molybdenum oxide sol under conditions relevant to flotation. Using infrared spectroscopy of treated mineral layers, the authors compare absorption bands produced by o…
This study examines the composition, structure, and preliminary catalytic behavior of propylene oxide polymerization catalysts produced by partial hydrolysis of the ferric chloride, propylene oxide complex. Catalysts prepared under controlled anhydrous conditions and hydrolyzed with one or two equiv…
This study examines the high-temperature condensation of dichlorosilane with several organochlorides, focusing on how organochloride structure affects product composition and yield. Experiments in a heated quartz tube at 600 to 650°C showed that chlorobenzene, p-chlorotoluene, and alpha-chloronaphth…
This paper reports the Friedel-Crafts acylation of cyclopentadienylrhenium tricarbonyl, extending a previously described synthesis of this organorhenium compound. Reactions with acetyl chloride and benzoyl chloride in the presence of aluminum chloride under nitrogen gave acetylcyclopentadienylrheniu…
