AbstractThe reaction of methyl esters of 4-aryl-2-hydroxy-4-oxobut-2-enoic (aroylpyruvic) acids with 2-aminobenzenesulfonamide in glacial acetic acid in the presence of anhydrous sodium acetate, 4-aryl-2-hydroxy-4-oxo-N-(2-sulfamoylphenyl)but-2-enamides were obtained. The analgesic and antimicrobial activity of the obtained compounds was studied.

AbstractThe reaction of thionylaniline with dicyclopentadiene has afforded the Diels–Alder adduct which has been oxidized into the corresponding sulfonamide bearing a benzothiazine moiety. Molecular and crystal structure of the sulfonamide has been elucidated via single-crystal X-ray diffraction analysis. Higher reactivity of the olefin functionality of the norbornene fragment has been found; the formation of two structural isomers has been revealed.

AbstractAn efficient method was developed for the one-pot synthesis of novel series of urea derivatives from 4-(4-aminophenyl)-3-morpholinone via in situ generated isocyanate through continuous-flow system. All the compounds were docked against DNA gyrase enzyme and antimicrobial and antifungal activities were investigated.

AbstractA series of chalcone-based 1,2,3-triazole compounds was synthesized Condensation of aldehydes and ketones results in the formation of chalcones. Terminal alkyne of chalcones and different aryl azides cyclization produced chalcone-based 1,2,3-triazoles through 1,3-dipolar cycloaddition (click reaction). The compounds were screened to evaluate their in vitro antimicrobial activities against Bacillus cereus, Escherichia coli bacteria and Aspergillus niger fungal strains. The analogues of 2-methyl, 4-chloro, 3-trifluormethyl, ester and 3,5-dichloro substitutions showed excellent zone of inhibition compared to ampicillin and bavistin drugs. Molecular docking studies showed good binding interactions with selected proteins glucosamine-6-phosphate and 3-phytase A of E. coli and A. niger, respectively.

Abstract3,3′-(1,4-Phenylene)bis[1-(4-R-phenyl)-5-phenyl-5,6-dihydro-1,2,4,5-tetrazinium] perchlorates have been transformed into stable tetrazinyl biradicals by the action of D-glucose in a slightly alkaline medium (NH4OH) in the presence of air oxygen. The tetrazinyl biradicals have been isolated in the individual state and characterized by means of cyclic voltammetry and elemental analysis as well as IR, UV, and ESR spectroscopy.

AbstractIt has been shown by DFT CAM-B3LYP/6-311++G(d,p) and CAM-B3LYP/6-311++G(d,p)/SDD calculations that the polydentate amidinyltetramethoxycarbonylcyclopentadienyl ligand and its Hg(II) and Tl(I) complexes are most stable in the form of ylide isomers, in which the hydrogen or metal atom is bonded to the terminal nitrogen atom of the amidinium fragment and, in the case of metal complexes, is additionally coordinated by the π-system of the cyclopentadiene ring. Alternative isomers with hydrogen or metal atoms bonded to carbon atoms of the cyclopentadiene ring or to carbonyl oxygen atoms of methoxycarbonyl substituents are energetically less stable by ΔEZPE = 4.1–15.1 kcal/mol.

AbstractRefluxing of 2,4,5-trimethoxyacetophenone with dimethyl formamide dimethyl acetal (DMF-DMA) in absence of solvent for 12 h resulted in the synthesis of enaminone, (2E)-3-(dimethylamino)-1-(2,4,5-trimethoxyphenyl)prop-2-en-1-one. Novel Biginelli-type compounds containing sulfaguanidine moiety were obtained by reacting the enaminone with sulfaguanidine, substituted benzaldehydes, and glacial acetic acid. All the prepared compounds were tested for antimicrobial activity by the agar diffusion method. Most of the compounds were active against gram-positive and gram-negative bacteria.

AbstractCondensation of 2-thioxo-2,3-dihydro-1H-spiro[benzo[h]quinazoline-5,1′-cycloheptane]-4(6H)-one with hydrazine hydrate afforded 2-hydrazinyl-3H-spiro[benzo[h]quinazoline-5,1′-cycloheptane]-4(6H)-one. The reaction of the latter with orthoformic acid ethyl ester or carbon disulfide yielded 5H-spiro[benzo[h][1,2,4]triazolo[3,4-b]quinazoline-6,1′-cycloheptane]-7(11H)-one and 9-mercapto-5H-spiro[benzo[h][1,2,4]triazolo[3,4-b]quinazoline-6,1 ′-cycloheptane]-7(11H)-one, respectively. Alkylation of the latter with methyl and ethyl iodides, allyl bromide, and benzyl chloride gave 9-sulfanyl-substituted 5H-spiro[benzo[h][1,2,4]triazolo[3,4-b]quinazoline-6,1′-cycloheptane]-7(11H)-ones. The synthesized compounds exhibited antibacterial properties.

AbstractThe rheological and filtration properties of the biopolymer solutions based on natural polymers, gum and starch, that affect the removal of drilled cuttings to the day surface, the creation of hydrodynamic pressure, and the borehole cleaning, were considered. Hydrodynamic pressure, in turn, predetermines possible arising of complications during well construction such as absorption of the drilling fluid or influx of formation fluids, hydraulic fracturing of the rocks, and contamination of the productive formations which are opened mainly via horizontal wellbore drilling. The peculiar features of the use of a combination of gums and starch in biopolymer drilling fluids, manifested in changes in the values of the process parameters of the drilling fluids, as well as in the physicomechanical processes of solution circulation in the well, were studied. By means of mathematical modeling, the change in the annular velocity profile for the biopolymer solutions containing the studied reagents (gum and starch) separately and jointly was demonstrated. In this regard, the basic equation describing the motion of a pseudoplastic liquid (the Ostwald–de Waele model) was used for finding the velocity profiles in an annular gap of 10 mm for the biopolymer solutions, and the optimal velocity profiles were graphically determined for the aqueous solutions of the biopolymer reagents. Basing on analysis of the obtained velocity solutions and the experimental data on the filtration and transport properties of the biopolymer compositions, the optimal concentrations of the reagents were determined.

AbstractSilver nanocomposites in the matrix of a copolymer of 1-vinyl-1,2,4-triazole with methacrylic acid were synthesized by the electrochemical method by combining the process of electrochemical polymerization with cathodic precipitation of metals on metal electrodes. Structure and composition of the obtained nanocomposites and nanocoatings were recorded using UV, IR, atomic absorption, and X-ray spectroscopy, thermogravimetric and elemental analyses. Transmission electron microscopy data show that the synthesized nanocomposites consist of particles with a diameter of 1 to 12 nm, predominantly spherical.

AbstractThe article discusses the main results of the academic studies in the field of organometallic chemistry of cyclic acetals conducted at the Academy of Sciences of the Republic of Bashkortostan by Academician D.L. Rakhmankulov. The results of the interaction of cyclic acetals and their heteroanalogues with Al-, Mg-, Si-organic compounds are presented. The relationship between the amount of carbon in cycloalkane and its activity in interaction with organoelement substances has been established.

AbstractPbCl2–PbO–SiO2 glasses doped with Nd3+ ions were studied. The photoluminescence intensity, absorption, microhardness, refractive index, and characteristic temperatures of the glasses were measured experimentally. Amorphous structure of the investigated samples was proved by X-ray diffraction (XRD). Energy dispersive X-ray analysis (EDAX) confirmed the incorporation of lead chloride into the glasses. PbCl2 additions cause decreases in the glass transition, crystallization, and melting temperatures of the lead silicate glasses due to the formation of new structural and chemical units and to significant changes in the glass network. A decrease in microhardness is a consequence of the structural changes. The glasses have high refractive indices in the range of 1.78 to 2.09. The spectral-luminescent properties of the neodymium ions in the PbCl2-PbO-SiO2 glasses were investigated in detail for the first time. The absorption spectra show typical Nd3+ absorption bands in the visible and infrared spectral regions. The short-wave absorption band lies in the range of 350–380 nm, being shifted to the ultraviolet region by 40 nm relative to the binary PbO-SiO2 glasses. The synthesized glasses exhibit intense IR photoluminescence, typical for neodymium. The photoluminescence intensity increases with an increase in the lead chloride proportion in the lead silicate oxochloride glasses. The addition PbCl2 to the lead silicate glasses causes reduction of the maximum phonon energy of the matrix. The decrease in the phonon energy decreases the probability of nonradiative relaxation. The Nd3+ ion occurring in a low-energy environment luminesces more efficiently, since the excitation energy is not dissipated via the thermal vibrations of the matrix. The studied glasses are promising materials for the infrared spectral region.

AbstractA rhodamine B derivative containing a terminal (4-hydroxybenzyl)triphenylphosphonium chloride substituent was synthesized. Its structure was determined using IR, 1H NMR, and 13C NMR spectroscopy. The spectral luminescent properties of the compound obtained and its complex formation in solutions with Co2+, Cu2+, Ni2+, and Zn2+ cations were studied. These ions are responsible for a contrasting ionochromic naked-eye effect with the crimson-red coloration of a colorless solution due to the isomerization of the rhodamine spirolactam form into an open form. The process is accompanied by the appearance of fluorescence in the region of 560–600 nm. The complex with zinc(II) cation exhibits particularly intensive emission, which gives the properties of a highly sensitive and effective chemosensor for Zn2+ ions to the obtained rhodamine.

AbstractNew tetrazole-containing derivatives of morpholin-4-yl-1,3,5-triazine and 4-methylpiperidin-1-yl-1,3,5-triazine were synthesized. The cytotoxic activity of the obtained compounds against human liver Huh-7 and human lung A549 tumor cell lines was tested by MTT assay. It was demonstrated that these substances do not show pronounced cytotoxic effects. The most significant antitumor activity was exhibited by 1,3,5-triazine containing a 5-phenyltetrazol-2-ylacetohydrazide moiety and a 4-methylpiperidine ring as substituents, as well as by 1,3,5-triazine bearing a 5-methyl-1H-tetrazol-1-ylacetohydrazide moiety and two morpholine rings. For these compounds, the interaction with DNA was studied by UV spectroscopy. Also, for N'-(4,6-dimorpholino-1,3,5-triazin-2-yl)-2-(5-methyl-1H-tetrazol-1-yl)acetohydrazide, the DNA binding constant was determined (Kbin 9.02×104 M−1), and the ability to inhibit the tyrosine kinase domain of the cell-surface receptors was evaluated. It was shown that the studied tetrazole-containing 1,3,5-triazine derivatives do not exhibit antioxidant activity against NO radicals and do not cause photoinduced hemolysis.

AbstractNMR spectra of 1-propylimidazole-4,5-dicarboxylic acid and its 1-alkyl C1-C4 derivatives in DMSO-d6 were studied. It was shown that these compounds are present in the zwitterion form in this solvent. The ionization constants of 1-propylimidazole-4,5-dicarboxylic acid in water were determined and their assignment was carried out, which is compatible with the assumption that this compound has a zwitterionic form in this solvent as well. Quantum chemical calculations confirmed both this assumption and the correctness of the assignment of deprotonation constants, and also allowed us to choose the preferred zwitter-ionic and monoanionic form of 1-propylimidazole-4,5-dicarboxylic acid from several alternative structures.

AbstractThe supramolecular system based on viologen calix[4]resorcinol and sodium alginate in an aqueous medium was studied by a set of physicochemical methods. It was found that sodium alginate and viologen calix[4]resorcinol in the range of macrocycle : polymer concentration ratios from 1 : 2 to 1 : 10 form stable nanoparticles capable of encapsulating biologically active hydrophobic substances. In the presence of encapsulated substrates, the selectivity of the action of quercetin and oleic acid against M-HeLa tumor cells increases by 2.47 and 1.14 times, respectively.

Erratum

AbstractThe 1-azole-8-aryl-BODIPY and 1,9-diazole-8-aryl-BODIPY derivatives were synthesized by the reaction of BODIPY with some azoles (1H-1,2,3-triazole, 1,2,4-triazole, 1H-tetrazole, pyrazole, benzopyrazole) in the presence of Selectfluor in moderate yield. The reaction proceeds regioselectively in 1(9)-position of the BODIPY ring, which was confirmed by single crystal X-ray analysis.

AbstractThe properties of composite films based on polyacrylonitrile and detonation nanodiamonds were studied. It was found that the surface properties of the films (roughness and specific free surface energy) do not change when nanodiamonds are added. It was shown by autoradiography technique with tritium-labeled nanodiamonds that the distribution of particles in a film depends on the modification of their surface. Additives of particles and heat treatment affect the mechanical behavior of the films, and the samples become more brittle. Modification of the nanodiamonds with perfluorononanoic acid leads to a decrease in the strength of the films.

AbstractInitial powders of Zr, Al, C and Zr, Al, ZrC were used for the synthesis of MAX phases of the compositions Zr2AlC and Zr3AlC2. The highest content (50.4 vol %) of the MAX phase Zr3AlC2 was obtained using the initial powders Zr/Al/ZrC in the ratio of components 1 : 1.5 : 2 with the addition of 5 vol % of Al. The optimal temperature for the synthesis of a material based on the MAX phase Zr2AlC is 1525°C, and that of the material based on Zr3AlC2—1575°C. The structure of the synthesized MAX materials includes elongated grains of the compositions Zr2AlC and Zr3AlC2, which determines their high strength. Zirconium carbide, as an intermediate phase, is always present in the final products. Due to the considerable evaporation of aluminum, the ZrO2 phase is also present in the synthesis products. Excess aluminum contributes to the maximal formation of Zr2AlC and Zr3AlC2 phases during synthesis.