Volume 89, Nº 2 (2019)

The physico-chemical basis of optimal conditions for synthesis of BaBiO₃ oxide, free from impurities of BaBiO₃ and BaBiO_3−x oxygen-deficient phases, is given. The reduction of time of the melt contact with a crucible makes it possible to obtain BaBiO₃ samples minimum polluted by a crucible material. It was found that an abnormal behavior of BaBiO₃ in the course of long-time annealing in air at 450°C is caused by the interaction with CO₂.

Kinetics and mechanism of the hydrazinolysis of oleic acid in the presence of a highly basic anionexchange resin AV-17-8 have been studied for the first time. The first reaction rate order has been found. The values of activation energy and entropy of the process have been determined. A plausible reaction mechanism involving a fixed resin cation has been proposed basing on the kinetic and IR spectroscopy data.

The structure of 5,5-bis(bromomethyl)-2-methyl-2-phenyl-1,3-dioxane 1 has been studied by means of ¹H and ¹³C NMR spectroscopy as well as X-ray diffraction analysis. The molecules of compound 1 exist in the chair conformation with the axially oriented phenyl group. The computer simulation using DFT approximation at the PBE/3ξ level has revealed the route of interconversion of the ring and the optimal conformation of the phenyl group corresponding to the data of X-ray diffraction analysis.

Isomeric biscyanomethylene-substituted 1,3- and 1,2-pyrilo-4-squaraines have been synthesized. The formation of a dye, derivative of 1,2-squarate, from the derivative of 1,3-squarate has been demonstrated for the first time. Electronic absorption spectra of the synthesized dyes have been studied. The molecular and crystal structure has been investigated by X-ray diffraction analysis. Both isomeric dyes exist in the cis-conformation.

Two-stage condensation of cycloalkyl ketones with dimethyl oxalate or alkyl acetates with dialkyl oxalates and cycloalkyl ketones produced disodium 1,2-bis(2-oxocycloalkylidene)ethane-1,2-diolates and disodium 4-alkoxy-4-oxo-1-(2-oxocycloalkylidene)but-2-ene-1,2-diolates, respectively. The structural features of the obtained compounds were discussed on the basis of their IR, ¹H NMR spectroscopy, and mass spectrometry data.

Bis[2-(4-pyridyl)ethyl]phosphine reacts with acrylonitrile under mild conditions to form bis[2-(4- pyridyl)ethyl](2-cyanoethyl)phosphine which is readily oxidized in air to the corresponding bis[2-(4-pyridyl)- ethyl](2-cyanoethyl)phosphine oxide. The latter compound reacts with 1,4-dihalobutanes according the scheme of polyquaternization with practically quantitative formation of high-molecular cationic compounds (ionenes) bearing phosphine oxide groups and pyridinium cycles in the main chain. The thus obtained ionenes enter the intermolecular interaction with anionic polyelectrolytes (polyacrylic acid, heparin). They were also found to exhibit antibacterial activity.

Enthalpies of complexation of diglycine (HL^±) with Pr³⁺ and Sm³⁺ ions at 303.15 K and I = 0.5 (KNO₃) have been determined by means of calorimetry. The thermodynamic parameters of the formation of diglycine complexes with Pr³⁺ and Sm³⁺ ions have been calculated at different molar ratios between metal and the ligand.

Zinc(II) complexes with 1,10-phenanthroline and tetrafluoroterephthalate and octafluorobiphenyl 4,4′-dicarboxylate anions have been synthesized. According to the IR spectral data, the complexation involves coordination of the metal ion to the nitrogen atoms of phenanthroline and carboxylate oxygen atom of the acid anion. The complexes show photoluminescence in the visible region of the spectrum. The structure of the complex salt [Zn(H₂O)₆][Zn(H₂O)₄(L²)₂] · H₂O, where L² is octafluorobiphenyl-4,4′-dicarboxylate anion (monodentate ligand), has been determined by X-ray analysis.

4,5-bis[(4-phenoxy)phenoxy]phthalonitrile was obtained by the reaction of 4,5-dichlorophthalonitrile with 4-phenoxyphenol. On its basis 2,3,9,10,16,17,23,24-octakis-[(4-phenoxy)phenoxy]phthalocyanine and its single- and double-decked complexes with erbium were synthesized. Spectral-luminescent properties of resulting phthalocyanines were studied. The tendency of phthalocyanines to association in dichloromethane depends on the structure of their molecules.

Linear Fisher classification functions, canonical linear discriminant functions, and trees (rules) for classification and prediction of the stability of sodium (18-crown-6Na⁺) and potassium coronates (18-crown-6K⁺) from the properties of aqueous-organic solvents (water—methanol, water—propan-2-ol, and water—acetonitrile) have been obtained basing on multivariate exploratory analysis. The proposed approach to prediction of the coronates stability has been verified using independent experimental data on the stability constants of sodium and potassium coronates in water—dioxane and water—acetone mixtures. The constructed classification functions and rules have possessed high predictive potential.

A procedure has been developed for the synthesis of gold glyconanoparticles with an average particle size of 15–30 nm and a low polydispersity index on the basis of natural hexose (d-glucose, d-galactose, d-mannose) sulfanylacetyl-, 3-sulfanylpropanoyl-, and 2-sulfanylbenzoylhydrazones and thiolated poly(2-deoxy-2-methacryloylamino-d-glucose).

A novel series of 1,2,3-triazolyl-pyrrolidinyl-quinolinolines are synthesised by the Click reaction of alkynes with aromatic azides catalysed by CuI under microwave assisted and conventional conditions. All synthesized 1,2,3-triazoles are screened for their in vitro antimicrobial activity against different bacterial and fungal pathogens. Majority of the synthesized compounds demonstrate moderate to good inhibition zones compared to the standard drugs.

A series of amide derivatives of 1,2-isoxazole combined with 1,2,4-thiadiazole are synthesized 11a–11j. Their chemical structures are confirmed by ¹H and ¹³C NMR, and mass spectra. The products are tested for their anticancer activity against four types of human cancer cell lines, including MCF-7 (breast), A549 (lung), Colo-205 (colon), and A2780 (ovarian). Etoposide is used as a positive control. Most of the compounds show good anticancer activity. The compounds 11b, 11c, 11d, 11e, 11g, and 11j demonstrate more potent activity than etoposide.

Utility of sulfadiazine and sulfaguanidine in synthesis of new series of pyrazoles and 2-pyridones is described. Diazotization of sulfadiazine that results in formation of diazonium salt 2 followed by coupling of the latter with active methylene compounds leads to hydrazinyl derivatives 3a–3d. Heterocyclization of compounds 3a–3c with hydrazine derivatives gives to a series of pyrazole derivatives 4–6. Similarly, a series of pyrazole derivatives 12–14 is developed from sulfaguanidine. Condensation of hydrazinyl derivatives 3a–3c with cyanoacetamide in the presence of a catalytic amount of piperidine gives 2-oxonicotinonitriles 15a–15c. Tests of the new synthesized compounds against four pathogenic gram (+ve) and gram (−ve) bacteria demonstrate their activity higher than that of the standard Amoxicillin.

New alkylated hydantoin as well as 2-thiohydantoins were synthesized for broadening the library of compounds screened for antitumor activity. Antitumor activity of the new compounds was evaluated against breast cancer cell line (MCF-7) and demonstrated moderate to good activity.

The transformations of methyl trifluoropyruvate pyrazin-2-ylimine in the cyclocondensation reactions with 2-aminothiazoline, amidines, aminocrotonitrile and aza-Diels—Alder reactions with cyanamines, leading to five- and six-membered trifluoromethyl-containing heterocycles, were studied. The possibility of using 4-(pyrazin-2-ylamino)-1-(prop-2-yn-1-yl)-4-(trifluoromethyl)-1H-imidazol-5(4H)-one, the product of methyl trifluoropyruvate pyrazin-2-ylimine cyclocondensation, for modification of phenothiazine by copper-catalyzed alkyne-azide 1,3-dipolar cycloaddition was shown.