Chemistry

Data Approximation for Plotting the Binodal Curve on the Phase Diagrams of Some Ternary Salt – Water – Isopropyl (n-Propyl) Alcohol Systems

A brief review of computational methods for the liquid-liquid equilibrium has been carried out, and their capabilities and limitations have been shown. Complications of such computational models for the liquid–liquid–solid equilibrium lead to a decreased accuracy of calculations. In this case, it is advisable for researchers to make use of the approximation of experimental data on the liquid – liquid and liquid – liquid – solid equilibria.

2-amino-3-formilchromen-4-one as “Connection-platform” in the Synthesis of Hybrid Systems under the Action of N-Nucleophiles

Показано, что 4H-хроменоны, функционализированные альдегидной группой в положении С3, способны образовывать гибридные системы, имеющие в своей структуре помимо хроменонового пиридиновый, пиримидиновый циклы. Кислая среда способствует раскрытию γ-лактонного фрагмента. Показана возможность дезактивации альдегидной группы с последующим деформилированием. 

On the Interaction of the Phosphoric Molybdenum Acid with the α-Amino Acids and Possible Applications of the Reaction Products in Ionometry

The conditions of synthesis of ion associates of phosphorus-molybdenum ions with protonated form of lysine hydrochloride have been considered. It has been shown that the phosphoric molybdenum acid undergoes hydrolysis with the formation of the following products: НРО42– + Мо12О42– + 11Н2О. At pH 2 in aqueous solutions, the PhMA is stable, exists as anion [РМо12О42]3– and interacts with protonated form of lysine with the formation of associates 3[НLys]+[FMC]3–.

Determination of Synthetic Food Dyes E110 and E124 in the Joint Presence by Vierordt’s Method and Derivative Spectrophotometry

The application of the Vierordt’s and the first derivative at the “zero crossing” methods was evaluated for the simultaneous determination of synthetic food dyes Yellow “sunset” (E110) and Ponso 4R (E124) in model solutions. The concentrations interval of components is established at which the principle of optical densities additivity is observed. For the implementation of the Vierordt’s method, wavelengths with the maximum difference in the absorption coefficients of the individual components (470.2 and 536.7 nm) were chosen.

Trifluoroacylation of Benzopirrolimidazolons under Various Conditions

The introduction of the (trifluoro)acetyl moiety into different heterocycles allows one to vary their physicochemical properties, change the nature and magnitude of biological activity, and also to carry out further chemical transformations. At the same time, modern methods of organic chemistry are aimed, inter alia, at increasing the efficiency of known and widely used chemical reactions and the possibility of directing along other paths when conducting syntheses under conditions, which are different from the classical ones.

Catalytic Conversion of Ethyl Alcohol on Zeolite Catalysts

This article describes the possibility of using bioethanol as a substitute for conventional fuel from petroleum feedstocks. Bioethanol obtained by fermentation from biomass is considered not only as an analogue of gasoline or a fuel additive, but also as a source of raw materials for the production of olefins, aromatic hydrocarbons and gasoline range hydrocarbons by means of catalytic conversion. At present, it is believed that the conversion of ethanol on zeolites proceeds in several stages.

Influence of Ascorbic Acid Isoforms on the Hydrodynamic Behavior of Chitosan Ascorbate Macromolecules in Aqueous Solution

The hydrodynamic behavior of chitosan macromolecules in aqueous solutions of ascorbic acid (AscA) diastereomers was studied by means of capillary viscometry. A comparison of these systems with chitosan solutions in such traditional solvent media as hydrochloric and acetic acids, Na-acetate buffer was made. Concentration dependencies of the specific viscosity were plotted, and the intrinsic viscosity and the Huggins constant were evaluated.

Test-Determination of Amoxicillin in Medications

Amoxicillin is a semi-synthetic aminopenicillin β-lactam series with a wide spectrum of antibacterial activity against many gram-positive and gram-negative microorganisms. It is included in the list of essential drugs. Test systems for the detection and identification of amoxicillin are missing. We have obtained indicator papers with immobilized ninhydrin and p-dimethylaminobenzaldehyde for the test determination of amoxicillin. The reaction conditions were selected, depending on the temperature and time. Color scales for visual colorimetric and colorimetric determination were constructed.

Transport Properties of Membranes on the Basis of Tetradecylammonium Associates with Complex Compounds Silver(I)-сefotaxime

Transport properties of the plasticized polyvinylchloride membranes on the basis of tetradecylammonium associates with complex connections silver (I) – cefotaxime in the conditions of a diffusive mass transfer and a direct current are investigated. With variation of concentration of electrode active substances (0.5; 1; 2; 3%), the external solutions contacting with membranes (10-2–10-7 M). It is established that resistance of membranes depends on the content of electrode active substances (EAS) and concentration of perimembrane solutions of a cefotaxime.

Interaction of Maleic Anhydride with 1,2-phenylenediamine under Different Conditions

The reaction of maleic anhydride with 1,2-phenylenediamine when heated in an aprotic solvent, regardless of temperature, proceeds with the initial formation of the primary addition product, namely, 4-[(2-aminophenyl)amino)-4-oxobut-2-enoic acid, which further undergoes heterocyclization within two ways, due to the presence of several electrophilic centers in the molecule, depending on the reaction conditions.

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