Том 67, № 2 (2018)

The authorsr works studying the hydrogen sorption properties of the magnesium-based materials are reviewed. The objects of the studies were highly dispersed powders of Mg—La—Ni and Mg—Mm—Ni alloys (Mm is misch metal) of the ternary eutectic, composites of magnesium alloys with extended carbon nanostructures, and composites of magnesium hydride with lanthanide oxides. The positive effect of lanthanide oxide additives on the process of hydro-gen desorption from magnesium hydride and the role of carbon nanofibers in these processes carried out at room temperatures are discussed.

Data on vapor-liquid equilibrium in benzene—DMSO, hexafluorobenzene—DMSO, and benzene—hexafluorobenzene—DMSO systems were obtained in the full-scale experiment. The ternary system is characterized by a specific ratio of the component boiling point differences: -0.5 °С in the biazeotropic component benzene—hexafluorobenzene and more than 100°C in the zeotropic benzene—DMSO and hexafluorobenzene—DMSO constituents. The Wilson equation parameters for the systems with large boiling point differences were evaluated using two sets of experimental data. A satisfactory description of the phase equilibrium was obtained. The values of the relative volatility of the hexafluorobenzene—benzene pair indicate the selectivity of DMSO in the process of extractive distillation of a biazeotropic mixture of different composition.

Solidus and liquidus temperatures of solid solutions with the face centered cubic lattice (α-phase) in Pd—Au—Sn and Pd—Cu—Sn ternary systems were determined. The liquidus surface projections for the α-phase were constructed, and position of the binary eutectic reaction L → α + Pd₃Sn in the studied ternary systems was predicted.

Nanocomposites obtained by in situ filling from amorphous poly(arylene ether ketones) based on 4,4´-difluorobenzophenone and 3,3-bis(4´-hydroxyphenyl)phthalide (phenolphthalein) with hydroxyl or benzophenone end groups were investigated. Metalalkoxysiloxanes, namely tris-(diethoxymethylsiloxy)iron, tetrakis-(diethoxymethylsiloxy)zirconium, and tetrakis- (diethoxymethylsiloxy)hafnium were used as precursors of the inorganic phase. It is shown that the morphology of the inorganic phase of nanocomposites can be varied from dispersed particles to a continuous network only by changing the type of the central metal atom of the metalalkoxysiloxane with the same organosilicon “framing”. The concentration of the precursor influences mainly the size of the filler particles. An application of tris-(diethoxymethylsiloxy)iron at a concentration of less than 14 wt.% makes it possible to obtain in situ filled polymers with a higher glass transition temperature than the ones obtained using tetrakis-(diethoxymethylsiloxy)zirconium or tetrakis-(diethoxymethylsiloxy)hafnium.

The effect of the state of hydrated surface of the bulk oxide photocatalysts, TiO₂, CeO₂, and ZnO on the rate of UV-induced oxidation of CO with atmospheric oxygen was studied. The activity of dehydroxylated catalyst samples evacuated at temperatures of >350 °C toward CO photooxidation decreases in the series CeO₂ > ZnO ≈ TiO₂, while that of partially hydrated samples after pretreatment at 20 °C changes in the order TiO₂ > ZnO ≥ CeO₂ ≈ 0. According to the results, the difference in the photocatalytic activity toward CO oxidation on the dehydrated ZnO, TiO₂, and CeO₂ catalysts is attributable to different concentrations of oxygen vacancies, which are formed more readily after high-temperature treatment on ZnO and CeO₂ and thus promote higher rate of CO photooxidation. Using a new technique for recording transmittance IR spectra, it was found that photoirradiation in the presence of adsorbed water and O₂ gives peroxides and hydroperoxides, with their concentrations decreasing in the series TiO₂ >> ZnO >> CeO₂. Most likely, these species are active intermediates of CO photooxidation with oxygen in the presence of adsorbed water. The hydrophobization effect was detected upon TiO₂ modification with zinc, resulting in removal of surface acid sites capable of adsorbing water. The TiO₂ modification with zinc increases the activity of CO photooxidation with respect to the oxidation catalyzed by samples pretreated at low temperatures (20—60 °C).

The reaction of the divalent ruthenium complexes [Cp^FRuCl]_n and [Cp^FRu(MeCN)₃]PF₆ with substituted pentafulvenes 1,2-(Me₂NCH)(CO₂Et)C₅H₃ and 1,3-(Me₂NCH)(CO₂Et)- C₅H₃ followed by hydrolysis affords new homoannular disubstituted ruthenocenes {1,2- (CO₂Et)(CHO)C₅H₃}RuCp^F and {1,3-(CO₂Et)(CHO)C₅H₃}RuCp^F (Cp^F = C₅Me₄CF₃), re- spectively.

The reactions of diazo esters with 2-arylcyclopropane-1,1-dicarboxylates, the represen- tatives of donor-acceptor cyclopropanes (DACs), mediated by Sc(OTf)₃, SnCl₄, and GaCl₃ proceeded with nitrogen elimination to give the C—C coupling products. No products of the formal [3+3] cycloaddition of diazo compounds to DACs were formed but the main reaction direction was addition of diazo ester to either 1,3- or 1,2-zwitterions generated upon Lewis acid-mediated cyclopropane ring opening giving rise to new 1,4- and 1,3-zwitterionic inter- mediates. The formed intermediates underwent further fragmentations and rearrangements to give substituted cyclopropanedi-, -tri-, and -tetracarboxylates. Mechanistic aspects of the observed reactions were discussed.

The nondestructive oxidation of 7-ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone by atmospheric oxygen in the ground (triplet ³Σ_g^–) and excited (singlet ¹Δ_g) states in different solvents (acetone, dioxane, ethanol, aqueous ethanol, water) at room temperature involves the initial formation of 7-ethyl-5,6,8-trihydroxy-2,3-dioxo-2,3-dihydro-1,4-naphthoquinone (dehydroechinochrome) accompanied by the release of an H₂O₂ molecule into the reaction medium. Dehydroechinochrome, being highly susceptible to hydration, successively reacts with two H₂O molecules to form 7-ethyl-2,2,3,3,5,6,8-heptahydroxy-2,3-dihydro- 1,4-naphthoquinone as the relatively stable final product. In this form, it can be isolated from the mixture of reaction products.

Convenient multicomponent methods for the synthesis of benzannulated dihydroindolizines based on quinoline or isoquinoline, malononitrile, aromatic aldehydes and α-halomethylcarbonyl compounds were developed. Several alternative protocols of using the reactants were studied, starting with separate generation of two most probable intermediates and ending with the four-component condensation of all reactants. The scope of applicability of these methods was found, depending on the initial compounds used. The reaction is highly stereoselective with predominant formation of one of the possible isomers.

Condensed pregnano[17,16-d]triazolines were produced in 1,3-dipolar cycloaddition of 16-dehydropregnenolone acetate with organic azides at 10 kbar. The structure of the synthesized compounds was determined by using two-dimensional NMR spectroscopy (¹H—¹H COSY, NOESY, HSQC, and HMBC).

A series of octa(thio)carbamoylated resorcinarenes was synthesized by the reactions of rccc-resorcinarenes with N,N-dimethylcarbamoyl and N,N-dimethylthiocarbamoyl chlorides in the presence of alkali carbonates. The derivatives with thiocarbamoyl groups were transformed into octa(carbamoylthio)resorcinarenes by the thione—thiol rearrangement. In a homogeneous medium octacarbamoylated resorcinarenes demonstrated high acceptor properties and selectivity to cesium cations but manifested low extraction ability towards alkali metal cations from the aqueous phase to organic one because of the formation of stable films at the interface. Resorcinarenes with thiocarbamoyl and carbamoylthio groups are capable of extracting lanthanides (Nd³⁺, Yb³⁺) from aqueous media and are selective to Nd³⁺ cations.

The reaction of poorly soluble manganese(II) bis(1-hydroxyethylidene)diphosphonate tetrahydrate (Mn(H₃L)₂•4H₂O) with 2-aminoethanol (H₂NCH₂CH₂OH) in an aqueous medium on heating to 70—80 оС causes the initial formation of soluble manganese(II) bis(1-hydroxyethylidene)diphosphonate tris(1-hydroxyethaneaminium) (Mn(H₃L)2• •3H₂NCH₂CH₂OH•4H₂O), which then disproportionates to slightly soluble manganese(II) (1-hydroxyethylidene)diphosphonate-2-hydroxyethaneaminium (MnH₂L•H₂NCH₂CH₂OH) and coordination polymer of 1-hydroxyethylidenediphosphonic acid with 2-aminoethanol containing no metal cations. In the course of the reaction, MnH₂L•H₂NCH₂CH₂OH precipitates as whiskers that are grouped into a leaf (lepidoid) structure. The latter was examined by IR spectroscopy, X-ray phase analysis, scanning electron microscopy, atomic force microscopy, optical microscopy, and thermal desorption of nitrogen. The starting and resulting manganese compounds refer to poorly soluble crystalline complexes. The presence of a 2-aminoethanol molecule in the final product leads to an increase in the solubility from 0.40 to 0.54 g in 100 mL of the solution. Poorly soluble MnH₂L•H₂NCH₂CH₂OH is easily converted to a soluble form by the treatment with 2-aminoethanol or 2-amino-2-(hydroxy- methyl)propane-1,3-diol (H₂NC(CH₂OH)3). The agronomical efficiency of a solution of the Mn(H₃L)₂•3H₂NCH₂CH₂OH•4H₂O complex was studied on the cultures of white lupine Degas, spring wheat Ester, spring rape, and pea Stabil.

In order to study the possibility of using a metal complex of the porphyrin series, Fe^IIICl-tetraphenylporphyrin (FeClTPP), and its polymeric form as antitumor agents for binary catalytic therapy, the technology of preparation of polymer particles containing FeClTPP was developed for the first time. The experimental data obtained allow one to conclude that the developed form using a copolymer of lactic and glycolic acids (ratio of monomer units 50: 50), ultrasonic homogenization, D-mannitol (as a cryoprotectant), the active agent to polymer ratio 1: 10, and the organic to aqueous phase ratio 1: 10 and 1: 20, respectively, has the optimal physicochemical parameters. It was found that the free substance of FeClTPP and polymer particles with FeClTPP are active against MCF-7 (human breast adenocarcinoma), HeLa (human cervical carcinoma), and MG-63 (human osteosarcoma) cell lines. The polymer particles containing FeClTFP exhibit the highest cytotoxic effect against MCF-7 lines as compared to the free substance. The results of the study indicate that both the substance of tetraphenylporphyrin and its resulting polymeric form are promising for the treatment of tumor diseases in binary catalytic therapy.

N-(N-[(2R,3R)-2,3-Dihydroxy-3-carboxypropionyl]glycyl)-β-d-glycopyranosylamines and N-[N-(formylcarbonyl)glycyl]-β-d-glycopyranosylamines, derivatives of lactose, human milk tri-, tetra-, and pentasaccharides, and synthetic di- and trisaccharides, were synthe- sized. N-Glycyl-β-d-glycopyranosylamines of these oligosaccharides were N-acylated with (+)-di-O-acetyl-l-tartaric anhydride, and the derivatives with α-glycol and terminal carboxy groups in the aglycon moiety were obtained after O-deacylation (70—80% yield). The short-term (80 s) selective oxidation of the α-glycol group of the tartaric acid residue in these derivatives with dilute periodic acid gave the target compounds with the terminal aldehyde group in aglycon in ~90% yield.

A reaction of 2,4-bis(α,α-dimethylbenzyl)phenol with TiCl₂(ОPrⁱ)2 and Ti(ОPrⁱ)₄ was used to obtain the coordination compounds (HL)₂L₂Ti₂Cl₂•MeC₆H₅ and L₄Ti₄(OPrⁱ)₈, respectively. The compounds were characterized by elemental analysis, NMR spectroscopy, and X-ray diffraction. The titanium(IV) coordination compounds obtained polymerize ethylene in the presence of binary cocatalysts {3Et₂AlCl + Bu₂Mg} or {3Et₃Al₂Cl₃ + Bu₂Mg} at moderate to high rates, giving rise to ultra-high molecular weight polyethylene with a wide range of molecular masses. The highest values of tensile strength (2.4 GPa) and modulus of elasticity (ε = 2.67%) were obtained for the sample with a molecular mass of 3.14•10⁶ Da under comparable conditions of orientation drawing of the film filaments. This sample was obtained when complex (HL)2L₂Ti₂Cl₂ was activated by a 3: 1 mixture of Et₂AlCl—Bu₂Mg.