Chemistry

Quantum chemical analysis of reactivity of several chromenopyrazoles

Authors: Menyailo I. E., Pozharov M. V., Zakharova T. V., Kostritsky A. Y., Demeshko I. A.

The article presents the results of quantum chemical calculation of reactivity indices of nine substituted chromenopyrazoles that can be potentially used as ligands for light emitting complex compounds. The molecules chosen for our study contain several potential complexation centers (nitrogen atoms of pyrazol ring and oxygen atoms of chromene fragment) as well as additional chromophoric groups capable of facilitating the excitation energy transfer from ligand to central ion. The molecular geometry was optimized using Hartree-Fock method and 6-311 G basis set implemented in Firefvly v.

Electroanalytical properties of planar sensors in aqueous environments of amoxicillin

Authors: Kulapina O. I., Mursalov R. K.

One of the widely used antibiotics of the penicillin series in medicine are amoxicillin and amoxiclav – the representatives of "protected" penicillins. To control the concentration of these antibiotics, HPLC, spectrophotometry, capillary electrophoresis are applicable, which are long-lasting, require expensive equipment, operators and are not applicable for the express determination of aminopenicillins in biological and medicinal aqueous.

The study of the physic-chemical properties of bentonite-based composite sorbents modified with carbon under the conditions of catalytic carbonization

Authors: Loseva A. S., Komov D. N., Lamikhova A. P., Kazarinov I. А.

The structural and sorption properties of composite sorbents based on natural bentonite modified with carbon compounds have been investigated. Modification of the initial bentonite by low-temperature (650°C) pyrolysis of sucrose in the presence of metal salts of the iron subgroup leads to a significant increase in the specific surface area of composite sorbents (up to 275 m2/g), this is due to low-temperature catalytic graphitization of the carbon fraction formed during pyrolysis.

Synthesis and structural features of 5-(4-bromophenyl)-3-((6-amino-2-mercaptopyrimidine)-4-amino))methylidene)-3Н-furan-2-one

Authors: Tikhomolova A. S., Mayorova O. A., Yegorova A. Y.

This work shows the possibility of synthesizing previously unknown 5-(4-bromophenyl)-3-((6-amino-2-mercaptopyrimidine)-4-amino)) methylidene-3H-furan-2-one containing a pharmacophore pyrimidine fragment by four-component one-pot reaction of malononitrile as the second methylene active component, thiourea, orthoester and 5-(4-bromophenyl)-3H-furan-2-one, which proceeds under mild conditions during thermal activation of the reaction mixture in isopropyl alcohol. Orthoester, as an electrophilic particle, makes it possible to introduce an additional carbon atom into the structure.

Study of the relationship between geometric isomerism and biologically active properties of compounds

Authors: Gasanov A. G., Ayyubov I. G., Hajiyeva G. E., Qurbanova F. S.

The results of the research in the field of studying the relationship of the geometric structure of organic compounds with their biological activity are presented. It has been shown that the stereospecific structure of organic and inorganic molecules can have a direct effect on the biologically active properties of substances. Among the known types of stereoisomerism (geometric and optical), this work summarizes the effect of various types of geometric isomerism on the bioactivity of compounds. In addition, the results of the authors’ own research are presented.

The prospect of using Shewhart control charts in assessing the quality of ionometric measurements by the method of adding a sample to a standar

Authors: Shatunov V. M., Fokina A. I., Ashikhmina T. Y.

Modern methods of quantitative physical and chemical measurements should necessarily include procedures for quality control of research results. Recently, the procedure for quality control of measurements using control charts is gaining particular popularity in the practice of analytical measurements. To date, the methods of potentiometric studies operating in the territory of the Russian Federation, in most cases, do not include quality control using this control procedure.

Reuse of a purified solution of cetyltrimethylammonium bromide for the synthesis of gold nanorods

Authors: Gudova Y. D., Kochubey V. I., Skaptsov A. A.

We investigate the possibility of reusing CTAB solutions for repeated synthesis of gold nanorods. Three tasks have been solved. The first task is to clean the growth solutions from gold nanorods. The second task is to develop a method using a purified cetyltrimethylammonium bromide solution for repeated synthesis of gold nanorods with the same optical properties as in the initial synthesis. The third task is to test the possibility of management of the optical properties of nanorods during repeated synthesis.

Study of the diffusion process in films sodium salt of carboxymethyl cellulose – drug

Authors: Shurshina A. S., Kulish E. I.

The transport properties of medicinal films based on sodium salt of carboxymethylcellulose and the antibiotic amikacin sulfate have been studied in this work. It has been shown that the process of sorption of water vapor by such films and the release of a drug from them proceeds in an abnormal diffusion mode, which is explained by the slowdown of relaxation processes in glassy polymers, which include the sodium salt of carboxymethylcellulose.

Synthesis and study of some properties of colloidal quantum dots of indium antimonide

Authors: Tsvetkova O. Y., Shtykov S. N., Zhukov D. N., Smirnova T. D.

Colloidal quantum dots of indium antimonide have been synthesized by a known technique. The shape and average diameters of quantum dots have been investigated by transmission electron microscopy using a transmission microscope. Controlling the size and shape of colloidal QDs provides information on the formation of the crystal structure of nanoparticles and their possible physical and optical properties. It has been found that InSb quantum dots are characterized by a polygonal shape.

Isolation and radiochemical purification of samarium isotopes using ion exchange resins АВ 17×8 AND KU-2

Authors: Salmenbayev S. E., Nurgaysinova N. K., Yessilkanov G. M., Temirzhanova А. E., Makarychev S. V.

The relevance of the research is caused by the need to develop a methodological base for determining 151Sm content in the soil cover of radioactively contaminated territories of Kazakhstan. The developed method for the determining of 151Sm will make it possible to assess the levels of soil contamination with this radionuclide, to determine the character of its spatial distribution, to allow estimating the internal exposure doses for the personnel and the population.

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