Vol 86, No 2 (2016)

Scandium(Magnesium)-containing bismuth titanates with the pyrochlore structure have been synthesized for the first time. Their homogeneity range has been determined by means of X-ray diffraction analysis and scanning electronic microscopy. Scandium and magnesium distribution over the cationic positions has been studied. Electrophysical properties of single-phase compounds have been studied. The total conductivity of the compounds is a function of magnesium (scandium) and bismuth concentrations.

The interaction of vanadyl acetate, vanadium(V) oxide, and vanadium(V) isopropylate with capronic acid has afforded a series of nanosized vanadium oxide powders. The products structure has been studied by X-ray diffraction analysis. Both amorphous and crystalline powders of vanadium oxide can be prepared depending on the starting compound, temperature, and the synthesis duration, the V₂O₃ (karelianite) structure being in all the cases the most thermodynamically stable. Photocatalytic properties of the prepared powders have been studied.

Relative stability of three molecular forms of diborane in the model single-walled carbon nanotubes has been studied by means of the PBE/3ζ hybrid DFT method. The influence of the force field of the nanotube results in the decrease of the В–В bond length, decrease of the energy difference between the orthogonal and the planar forms, and appearance of high negative charge at the В₂Н₄ molecule. The strengthening of these effects is not related to the length and geometry [(n,n) or (n,0)] of the nanotube, but is determined only by the nanotube diameter.

Oxidative dissolution of nickel in the benzyl halogenide – dipolar aprotic solvent system in the presence of air oxygen proceeds with the formation of benzaldehyde, benzyl alcohol, 1,2-diphenylethane, and trace amounts of 4,4'-ditolyl. Spectrophotometry studies have revealed that the oxidation products are formed in the solution rather than at the nickel surface. It has been shown that the oxygen adsorbed at the nickel surface practically does not pass into the solution.

The reactions of 2-methylene- and 2-benzylideneadamantane with acetyl nitrate have been studied. In the case of 2-methyleneadamantane, the reaction proceeds via addition of nitronium cation at the double bond followed by stabilization of 2-nitromethyl-2-adamantyl carbocation. In the case of 2-benzylidenadamantane, ortho-substitution at the benzene ring occurred predominantly.

Hydrogenation of carbonitriles catalyzed by nickel nanoparticles in isopropanol proceeds under atmospheric pressure of hydrogen within 6–15 h to yield mainly secondary amines. Hydrogenation of α-aminonitriles results in reductive decyanation. β-Aminonitriles undergo hydrogenolysis at the nitrogen–carbon bond.

Three-component reaction of methyl 2-furanoylpyruvate with an aromatic aldehyde and 5-aminotetrazole monohydrate has afforded methyl 6-aryl(hetaryl)-5-(2-furanoyl)-3,6-dihydrotetrazolo[1,5-a]-pyrimidine-4-carboxylates. Hypoglycemic activity of the prepared compounds has been studied.

Reaction of 4-fluoro-N-sulfinylaniline with norbornene and norbornadiene has afforded the Diels–Alder adducts of benzothiazine structure that have been oxidized into the corresponding benzothiazine sulfonamides. Structure of the obtained compounds and stereochemistry of the diene addition and epoxidation of norbornene olefin bonds have established by means of X-ray diffraction method.

Reactions of 1,2,4-triazole-3-thiols with 2-bromopropionic acid, 2-bromocaproic acid, ethylene chlorohydrine, chloroacetamide, 3-bromo-4-methoxybenzyl chloride, 2-methoxy-5-acetylbenzyl chloride, and 2-(2-chlorophenoxy)ethyl chloride in the presence of KOH have afforded new 3-sulfanyl-1,2,4-triazoles in high yields. Aminomethylation of 1,2,4-triazole-3-thiols in the presence of formaldehyde has given the corresponding 2-aminomethyl-2H-1,2,4-triazole-3(4H)-thiones. Interaction of triazole-3-thiols with formalin and acrylonitrile has resulted in the formation of N²-hydroxymethyl- and 3-(2-cyanoethyl)sulfanyl derivatives.

Per-6-O-(tert-butyl)(diphenyl)silyl-β-silylcyclodextrin has been obtained regioselectively via the reaction with tert-butyldiphenylchlorosilane. Further treatment of the product with chlorosilanes has led to the corresponding derivatives of β-cyclodextrin with mixed silyl groups at the primary hydroxyl groups.

New method for synthesis of phosphorylated methylene quinones via bromination of the sterically hindered phenol [prepared via benzylation of secondary chlorophosphines with 4-(methoxymethyl)-2,6-di-tert-butylphenol] with N-bromosuccinimide followed by dehydrobromination with trimethyl orthoformate has been developed. Tertiary phosphine oxides containing the fragment of sterically hindered phenol and amine or acetonyl group have been synthesized for the first time in the reaction of phosphorylated methylene quinones with N- and C-nucleophiles.

Acylation of alkyl- and 1,1′-dialkylferrocene alcohols and diols as well as (3,4,4-trichlorobut-3-ene-1-ol-1-yl)-4,5-cymantrene with dichloroisothiazole- and 5-arylisoxazole-3-carbonyl chlorides has afforded esters containing 1,2-azoles fragments. Some of the obtained compounds have exhibited potentiating action in the binary mixtures with insecticides.

New polymeric materials containing dinuclear double-stranded zinc(II) helicate with bis(1,2,3,7,9-pentamethyldipyrrin-8-yl)methane have been prepared on the basis of poly(methyl methacrylate) and tetraethoxysilane. The zinc(II) complex [Zn₂L₂] retains its fluorescence properties in a poly(methyl methacrylate) film. The photostability of [Zn₂L₂] in poly(methyl methacrylate) is higher by a factor of ≈2.5 than in the benzene solution. Conditions have been found for the preparation of [Zn₂L₂]-doped silicate matrix based on tetraethoxysilane via the sol–gel method. The [Zn₂L₂] complex in the tetraethoxysilane solid matrix shows a weak fluorescence with its maximum at λ = 545–549 nm.

Five new ruthenium(III) complexes of the general formulas [RuCl(H₂O)L₂] (1–4) and [RuCl₃(H₂O)(HL)₂] (5), where L = benzohydroximato (1), salicylhydroximato (2), acetohydroximato (3), hydroxyureato (4), LH = N-hydroxy-N-phenylbenzamide (5), were synthesized by reaction of RuCl₃ · 3H₂O with the corresponding hydroxamic acids at a molar ratio of 1: 2 molar. The complexes were characterized by elemental analyses and FT-IR, UV-Vis, ¹H and ¹³C NMR, and mass spectra. The complexes showed higher antibacterial activity against ten pathogenic bacterial strains than the corresponding ligands. The anticancer activity of the complexes against IMR-32 (neuroblastoma) cancer and CHO (Chinese hamster ovary) normal cell lines was evaluated using MTT assay with respect to camptothecin as control. Complex 5 was found to exhibit an appreciable cytotoxicity against IMR-32 cell line with an IC₅₀ value of 102.27 μM.

The quinoline derivatives were synthesized from 2-aminobenzyl alcohols and secondary alcohols by the direct one-step synthesis using the iridium complexes as catalyst. This efficient and easy method is suitable for all kinds of substituted quinolines.

Two new Cu(I) complexes, Cu(NPIP)(PPh3)2 (1) and Cu(MPIP)(PPh3)2 (2), (NHPIP: 2-(4-nitrophenyl) imidazole-2,9-dimethyl-1,10-phenanthroline; MHPIP: 2-(4-methylphenyl)imidazole-2,9-dimethyl-1,10-phenanthroline) have been synthesized and characterized by element analysis, IR and ¹H NMR spectra. TG experiments demonstrated that the complexes were stable up to ca 230°C indicating their high thermal stability. According to fluorescence spectra, the complexes exhibited yellow emission at 602 nm under excitation at 260 nm.

A series of novel dihydro-alkylthio-benzyloxopyrimidine (S-DABO) and 1-[(2-hydroxyethoxy) methyl]-6-(phenylthio)thymine (HEPT) analogs bearing a (benzo[d]thiazol-2-yl)methyl moiety at the C⁶ position of the pyrimidine core have been synthesized. 5-Allyl-6-{(benzo[d]thiazol-2-yl)methyl}-2-thiouracil and 5-allyl-6-{(benzo-[d]thiazol-2-yl)methyl}uracil were alkylated to give, respectively, S²- and N¹- ethoxymethyl and -methylthiomethyl uracil derivatives. 5-Allyl-6-[(benzo[d]thiazol-2-yl)methyl]-2-thiouracil was also alkylated by S² with methyl bromoacetate and hydrolyzed to the corresponding acid.

The corrosion behavior of carbon steel in PO-6TS-M foaming solution was studied. Several kinds of inhibiting additives were tested for their ability to reduce the corrosion rate of steel. The antipyrene additive to the foaming solution was shown to be the most effective in reducing corrosion rate of carbon steel. The optimum concentration of the inhibitor additive was determined.

The influence of chemical impurities on hygroscopic properties, as well as on the grinding and modification efficiency of ammonium phosphate and ammonium sulfate was analyzed. It was shown that application of chemically pure ammonium sulfate and ammonium phosphate free of ammonium fluoride and magnesium phosphate impurities provides the best conditions for obtaining fire extinguishing dry powders with high fire suppression ability and properties that satisfy relevant specifications.

The main methods of flame-retardant finishing of different-purpose textiles (technical textiles, home textiles, clothing and decorative fabrics, etc.) were overviewed. The flammability data for the textiles of different chemical nature were presented.

The possibility of plasma chemical conversion of hydrogen chloride was explored. It was shown that, for the typical conditions of atmospheric pressure discharges, the use of pure HCl as the plasma-forming gas does not provide the conversion degrees higher than 4%. It was found that high (>95%) HCl conversion degrees, as well as maximum yields of Cl₂ may be obtained in HCl-O₂ mixtures due to the plasma-assisted oxidative decomposition of the reactant. The optimal process conditions in terms of the electron density and feed gas composition were determined.

Problems of dyeing of para-aramid fabrics with preservation of their performance characteristics: incombustibility, high strength, and durability are considered. Evidence for the efficiency of domestic polyurethane polymers for durable dyeing of aramid fabrics by inorganic black pigment is obtained. The technologies for resist and deep dyeing of fire-resistant fabrics are demanded by manufacturers and are competitive.