Том 68, № 11 (2019)

The results of the last 20 year research on the development of rare earth cobaltate- and nickelate-based catalysts of the partial oxidation of methane (POM) are summarized. New way of synthesis of these catalysts based on the decomposition of complex oxide precursors in the reducing environment is discussed. It was found that the high mobility of oxygen in LaSrCoO₄ is accompanied by a significant catalytic activity of this complex oxide in methane oxidation. High catalytic performance of NdCaCoO₄ in POM might be caused by the reductive decomposition of this complex oxide at a temperature above 900 °C and the formation of closely packed agglomerates of nanoparticles of metallic cobalt, Nd₂O₃, and CaO. The studies focused on decreasing POM temperature via substitution of cobalt by nickel in complex oxide precursors as well as the works considering decomposition processes in order to obtain metal-oxide nanocomposites with the optimum catalytic performance are discussed. This work shows that the reductive decomposition of Nd_2−xCa_x(Co_1−yNi_y)O_4−d and of the related complex oxides opens up new possibilities for the development of metal-oxide catalysts of the partial oxidation of methane and other catalytic oxidation processes.

The review considers methods for modifying oligo- and polymers of lactic acid by macrocyclic moieties (cyclodextrin, tetrapyrrole, and calixarene) and the effect of modifiers on the complexing, thermal, and aggregation properties. Analytical characteristics of oligolactide-based sensors and biosensors are discussed, with particular emphasis on the mechanism of signal generation and the contribution of modified materials to the selectivity and sensitivity of analysis.

Thermodynamic modeling of the process of chemical vapor deposition (CVD) of boron-containing films in the chemical system B—C—O—H was carried out. The possibility to use trialkyl borates B(OAlk)₃ (Alk = Et, Prⁱ) and their mixtures with helium, hydrogen, and ammonia to fabricate films of different composition was demonstrated. The CVD phase diagrams of the systems in question were calculated. The nature of the boundaries on these sections was analyzed. The chemical reaction equations determining the position of such lines are derived. Chemical equilibria corresponding to these reactions can be used to control the CVD process.

The corrosion of the Au anode in aqueous solution of 1,4-diaminobutane (DAB) was studied by gravimetric analysis. The corrosion products were found to reduce at a steel cathode under galvanostatic conditions to form electrolytic precipitate of Au. Complex of Au with DAB was found to form in the solution, the structure of the complex was suggested. The kinetic of electrochemical corrosion of the Au anode in the DAB solution was also studied.

The structural and energetic characteristics of the compounds formed by the reaction of diethylamine (DEA) with protic acids (sulfuric (H₂SO₄), methanesulfonic (MsOH), trifluoromethanesulfonic (TfOH), and para-toluenesulfonic (TsOH)) were examined using quantum chemical computations (B3LYP-GD3/6-31++G(d,p)). The strength of the hydrogen bonds in the ion pairs formed was quantitatively estimated by the QTAIM theory and NBO analysis. The results of the quantum chemical computations and the obtained thermal (phase transition and decomposition temperatures) and physicochemical (viscosity and conductivity) characteristics indicate that the reactions of DEA with the acids afford salts. The salts with the melting points higher than 100 °C are formed in the case of DEA/OTf(OTs), while protic ionic liquids are produced in the case of DEA/OMs(HSO₄).

Graphene oxide (GO) synthesized according to the modified Hummers method was reduced by supercritical isopropyl alcohol (SCI), supercritical acetone (SCA), and supercritical water (SCW). Methods free of toxic reducing agents were developed for the graphene production. The composition, morphology, and structure of synthesized graphene were determined using CHN analysis, XRD, Raman spectroscopy, and scanning electron microscopy. The best results were acquired in the case of GO reduction in SCA and SCI at high parameters.

Complexes of palladium(II) with N-heterocyclic carbenes of the PEPPSI-type were synthesized by the reaction of PdCl₂ with 1-adamantyl-3-(R-methyl)-1H-imidazolium salts. These complexes were used as productive precatalysts for substituted thiophene and imidazole arylation by C—H-activation.

Photoprocesses of bis(15-crown-5)-1,4-distyrylbenzene (DSB) and its complexes with barium and lead perchlorates in MeCN were studied by absorption, luminescence, and laser kinetic spectroscopies. Triplet DSB complexes are involved in the degradation of electronic excitation energy along with the trans—cis-isomerization and fluorescence processes. The most effective intersystem crossing was observed for the complex with lead perchlorate. The process is accompanied by a decrease in the quantum yield of DSB fluorescence and no trans—cis-isomerization is observed in this case. Shifts of spectral bands observed in the absorption and fluorescence spectra and the changes in the band intensities as well as the ability of DSB to form the 2: 2 bisandwich complex with barium perchlorate were explained using the results of quantum chemical calculations.

The results of the study of various modification methods of polymer microspheres for their use in immunochemical reactions as bioligand carriers are reported. Ion etching and electron microscopy were used to show that the copolymer microspheres have a porous structure non-uniform in density. The Maillard reaction was used for the first time in the modification of copolymer microspheres by dextrans of different molecular weight as a simplest way of covalent immobilization of saccharides on their surface. The physicochemical properties of polystyrene-divinylbenzene and polyglycidyl methacrylate-ethylene glycol dimethacrylate microspheres modified with diamines and dextrans were determined for the first time. The conditions under which the bioligand (diphtheria toxoid) immobilized on their surface retained the native conformation and the diagnostics obtained on their basis have high sensitivity were revealed.

New type dispiroindolinones, dispiroimidazolidine-4,3′-pyrrolidine-2′,3″-indolinones unsubstituted at position 4′ of the central pyrrolidine ring, were synthesized by the 1,3-dipolar cycloaddition of azomethine ylides, generated from N-alkyl-substituted amino acids and isatines, to 5-methylidene-substituted 3-phenylhydantoin.

An approach to p-tert-butylthiacalix[4]arene derivatives functionalized with lactic acid fragments in three conformations (cone, partial cone, 1,3-alternate) was developed. The use of tetraglyme as a solvent and magnesium sulfate with p-toluenesulfonic acid as co-condensation catalysts made it possible to obtain the desired products without admixtures of oligolactic acid. The structure of the synthesized macrocycles was characterized by a complex of physico-chemical methods. The thermal properties of the synthesized lactic acid copolyesters were studied by simultaneous thermogravimetry and differential scanning calorimetry analysis. Significant effect of the p-tert-butylthiacalix[4]arene platform on the thermal stability of the obtained products was demonstrated. Nanoscale particles of the synthesized macrocycles with a low polydispersity index were obtained using nanoprecipitation from methanol or acetone into a buffer solution.

3,3-Disubstituted piperidin-2-ones were obtained by alkylation of carboxylic acid esters with 1-(3-halopropyl)-2,5-dimethylpyrroles using lithium diisopropylamide as a base followed by the removal of 2,5-dimethylpyrrole protection and intramolecular cyclization. The overall yields of the target products amounted to 78% in two synthetic steps.

High molecular weight block terpolymers with different contents of polypropylene carbonate and cyclohexene carbonate units in the polymer chain were synthesized by the copolymerization of carbon dioxide, propylene oxide, and cyclohexene oxide. Zinc adipate was used as a catalyst. The terpolymerization products were characterized by ¹H and ¹³C NMR spectroscopy, IR spectroscopy, GPC, DSC, and DMA methods. The influence of the reaction conditions on the composition, microstructure, and molecular-weight and thermal characteristics was studied.

The conceptual possibility to synthesize bacterial cellulose nitrates with the use of commercial mixed acid was demonstrated. The initial bacterial cellulose was produced by the Medusomyces gisevii Sa-12 symbiotic culture in a synthetic nutrient broth in a Binder constant climate chamber. The resulting bacterial cellulose nitrate sample had 11.45% nitrogen content, 1900 cP viscosity, 15.8% solubility in ethanol—diethyl ether mixture, and 0.10% ash content. An extremely high sample viscosity (organogelation) in a ∼2% solution in acetone was observed.

Sodium benzeneselenolate adds regio- and stereoselectively to 3-(trimethylsilyl)prop-2-yn-amides to give (Z)-3-(phenylselanyl)prop-2-enamides.