Publications (14)5.64 Total impact
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Article: X-ray diffraction, magnetochemical, and quantum chemical study of the structure and properties of binuclear copper(II) complexes
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ABSTRACT: The binuclear chelates of copper(II) based on the tridentate azomethine ligands were synthesized and characterized by elemental analysis, IR, 1H NMR spectroscopy, X-ray absorption spectroscopy (XANES and EXAFS), and magnetic measurements. The quantum-chemical study of the structure and calculation of magnetic properties of the obtained metal-chelates was performed using the density functional theory with the broken symmetry technique. The performed magnetochemical studies in the temperature range 2–300 K suggest the existence of antiferromagnetic exchange interaction in all obtained complexes. The parameters of the exchange interaction −2J > 260 cm−1 were determined experimentally for all compounds, the experimental data is in a good agreement with the results of quantum-chemical calculations.Russian Journal of General Chemistry 11/2012; 82(11):1770. · 0.47 Impact Factor -
Article: Synthesis and characteristics of the composites based on poly(caproamide) and multiwalled carbon nanotubes
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ABSTRACT: Polycaproamide composites are synthesized by the anionic activated bulk polymerization of ɛ-caprolactam in the presence of 0.1–5.0 wt % of multiwalled carbon nanotubes and using low-molecularmass monofunctional (N-acetyl-ɛ-caprolactam) and macromolecular polyfunctional (aromatic polyimides) activating agents. The effect of nanotubes on the polymerization of ɛ-caprolactam is studied, and this effect is shown to become more pronounced as the concentration of nanotubes is increased. The effect of nanotubes on the microstructure, phase composition, water sorption, thermophysical, mechanical, and friction characteristics of poly(caproamide) is analyzed.Polymer Science Series C 05/2012; 51(1):63-73. · 0.29 Impact Factor -
Article: Cocatalytic effect of palladium and zinc in the condensation of alcohol carbon backbones into hydrocarbons
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ABSTRACT: The results of the direct conversion of ethanol and its mixture with glycerol into a C4–C10+ alkane and olefin fraction in the presence of Pd-, Zn-, and Pd-Zn-containing catalysts, which were prepared by supporting homo- and heterometallic acetate complexes onto the surface of γ-Al2O3, are reported. It was found that, in the presence of mono- and bicomponent Pd-ZnO (Pd; ZnO)/γ-Al2O3 systems, selectivity in the formation of alkanes, olefins, or their mixtures in the target fraction can be controlled as a result of the cocatalytic effect of active components that are responsible for the catalyst activity in condensation and hydrogenation reactions. The structures of the active components were studied and the genesis of the catalytic systems was characterized using XAFS, XPS, and XRD analysis. It was found that the addition of glycerol considerably increased the yield of the target hydrocarbon fraction.Kinetics and Catalysis 04/2012; 52(2):258-272. · 0.64 Impact Factor -
Article: Alumina-platinum catalyst in the reductive dehydration of ethanol and diethyl ether to alkanes
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ABSTRACT: The reductive dehydration of ethanol and diethyl ether selectively occurs with the formation of alkanes to C10+ on an AP-64 alumina-platinum catalyst (0.6 wt % Pt/γ-Al2O3) after its reduction with hydrogen at 450°C for 12 h in Ar. It was found that one of the main reaction paths is the insertion of ethylene into substrate intermediates with the predominant formation of normal alkanes. It was found by XAFS spectroscopy that Pt2Al intermetallide particles were formed along with platinum metal clusters after long reduction. The ammonia TPD data indicated a change in the acid properties of the surface after the long reduction of the catalyst: the concentration of medium-strength surface aprotic acid sites increased by a factor of 2. It was found that the interaction of aprotic sites with water vapor resulted in the formation of strong proton acid sites. It is likely that these latter are responsible for the growth of a carbon skeleton in the course of alkane formation from ethanol.Kinetics and Catalysis 04/2012; 51(4):548-558. · 0.64 Impact Factor -
Article: Polycaproamide films containing ionic liquids: Microstructure and properties
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ABSTRACT: Films of polycaproamide and its composites containing ionic liquids (ILs) derived from 1-methyl-3-ethylimidazolium cation and N(CF3SO2)2 or N(CN)2 anions having crystalline structures were cast from solutions in formic acid. The structure and concentration of the ILs were shown to affect the conductivity (up to ∼10−4 S cm−1 25°C), microstructure (studied by X-ray diffraction, SEM, and AFM), and thermomechanical properties of the films.Bulletin of the Russian Academy of Sciences Physics 04/2012; 75(2):211-216. -
Article: An in situ cell for investigation of the catalyst structure using synchrotron radiation
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ABSTRACT: Design of a cell for in situ characterization of heterogeneous catalysts by X-ray absorption spectroscopy EXAFS/XANES and X-ray diffraction on synchrotron radiation at high temperatures in a controllable gas medium, which was implemented at the Structural Materials Science end-station installed at KCSRNT, is presented. First results on nanostructural evolution of Pt/γ-Al2O3, Pd/γ-Al2O3 and other catalysts during various treatments — oxidation in oxygen, reduction in H2/N2, and annealing in vacuum — are reported. Keywords in situ –catalysts–EXAFS–XANESJournal of Structural Chemistry 04/2012; 51:20-27. · 0.59 Impact Factor -
Article: Structure and properties of precipitation-hardening ceramic Ti-Zr-C and Ti-Ta-C materials
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ABSTRACT: Precipitation hardening alloys of the Ti-Ta-C and Ti-Zr-C systems produced by self-propagating high-temperature synthesis (SHS) have been studied. Optimum compositions of the alloys and heat-treatment conditions, under which the decomposition of supersaturated solid solution accompanied by the precipitation of fine particles both inside carbide grains and at their boundaries occurs, have been determined. The precipitation hardening ceramic materials exhibit high hardness (∼15–23 GPa) and heat resistance (the mass increase of the Ti-9.4% Ta-10.5% C alloy is less than 8 g/m2 during a 50-h exposure in air at 800°C) and can be recommended for the application as materials for deposited multifunctional coatings, high-temperature contacts, evaporation crucibles, and abrasion-resistive tools.The Physics of Metals and Metallography 04/2012; 109(1):95-105. · 0.54 Impact Factor -
Article: Effect of 1,1,5-trihydroperfluoropentanol and formulations based on it on the structure of oriented polycaproamide fibers
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ABSTRACT: Polycaproamide fibers, unmodified and modified with 1,1,5-trihydroperfluoropentanol and its formulations with copper diacetate bis(ɛ-caprolactamate) or N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-benzenediurea, were studied by X-ray diffraction.Russian Journal of Applied Chemistry 04/2012; 82(1):157-161. · 0.28 Impact Factor -
Article: Atomic structure of the copper bromide complex based on benzoin 1′-phthalazinylhydrazone: DFT and X-ray absorption spectroscopy analysis
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ABSTRACT: A copper bromide complex based on benzoin 1′-phthalazinylhydrazone is synthesized. Within density functional theory (OPBE/TZP) the optimal structural parameters of the complex are determined. X-ray Absorption Near-Edge Structure (XANES) spectra above the K absorption edge of copper are measured in the copper bromide complex. Theoretical XANES spectra of the K absorption edge of copper are calculated based on the full multiple scattering method and in the full potential of the finite difference method. Good agreement between the theoretical XANES spectrum and the experimental data is obtained. Keywordsatomic structure–density functional theory–XANES spectroscopyJournal of Structural Chemistry 04/2012; 51(6):1075-1080. · 0.59 Impact Factor -
Article: Synthesis and structural study of the ordered germanium nanorod arrays
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ABSTRACT: A new approach to synthesis of the ordered germanium nanorod arrays using thermal sputtering on the matrices of porous alumina A new approach to synthesis of the ordered germanium nanorod arrays using thermal sputtering on the matrices of porous alumina with the ordered channel arrangement is presented. The synthesized filamentary nanostructures were examined by scanning electron with the ordered channel arrangement is presented. The synthesized filamentary nanostructures were examined by scanning electron microscopy (SEM), EXAFS and XANES spectroscopy. Data on nanorod geometry in arrays, parameters of the local atomic structure microscopy (SEM), EXAFS and XANES spectroscopy. Data on nanorod geometry in arrays, parameters of the local atomic structure such as interatomic distances and coordination numbers for initial samples and those annealed at 450°C in the argon atmosphere, such as interatomic distances and coordination numbers for initial samples and those annealed at 450°C in the argon atmosphere, and data on changes in the electronic states near the absorption K-edge were acquired. A comparison was made with the data of EXAFS studies of a continuous Ge film synthesized on a smooth and data on changes in the electronic states near the absorption K-edge were acquired. A comparison was made with the data of EXAFS studies of a continuous Ge film synthesized on a smooth surface of non-porous Al2O3. surface of non-porous Al2O3. > Keywordsporous Al2O3 Keywordsporous Al2O3 –filamentary Ge nanostructures–Ge films–scanning electron microscopy–XANES spectroscopy –filamentary Ge nanostructures–Ge films–scanning electron microscopy–XANES spectroscopyJournal of Structural Chemistry 04/2012; 51:132-136. · 0.59 Impact Factor -
Article: Molecular design of new magnetically active copper complexes with heteroaromatic schiff bases and azo compounds
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ABSTRACT: Copper chelates with tridentate ligands containing pyridine or pyrazole ring at the azomethine or azo fragment were synthesized by chemical electrochemical methods, and their structure was characterized by the EXAFS spectra. Thermal magnetochemical analysis of the complexes revealed antiferromagnetic exchange interaction in all complexes. The exchange interaction parameter of the complex containing an N-tosylamino group in the ortho position with respect to the azomethine group is much lesser than that of the corresponding complex having an oxygen atom in the same position. The copper chelate derived from azopyrazole ligand shows low-temperature ferromagnetic phase transition.Russian Journal of General Chemistry 05/2008; 78(6):1230-1235. · 0.47 Impact Factor -
Article: EXAFS study of copper complexes with azomethinic ligand environment
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ABSTRACT: A series of copper metallochelates C22H18CuN4O2 X (X = Se, S, O) as models of active centers of natural metalloproteins have been synthesized on the basis of new azomethine ligand systems. The structure of the complexes has been studied by extended X-ray absorption fine-structure spectroscopy. It is shown that, in the metallochelates with X = Se or S, one azomethine chalcogen-containing ligand undergoes tridentate interaction with copper ions, while the other ligand is an acetate group. As a result, a complex with the N2O2 X environment is formed, where one of the oxygen atoms of the acetate group is at a large distance from the metal ion: R = 2.56–2.68 Å. For the metallochelate with X = O, coordination of the acetate group by a copper ion is found to be absent, and only interaction with azomethine ligands having average Cu-N/O distances R = 1.96–2.04 Å is observed.Bulletin of the Russian Academy of Sciences Physics 03/2008; 72(4):468-470. -
Article: Synthesis of 2-butyl-4,9-decadienoic and 2-butyl-4,9-dimethyl-4,9-decadienoic acids, structural analogues of cygerol
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ABSTRACT: 2-Butyl-4,9-decadienoic and 2-butyl-4,9-dimethyl-4,9-decadienoic acids, structural isomers of 2-cyclohexylgeranylacetic acid, which is an active component of the wound healing ointment cygerol, have been synthesized. Hydrocarbon chains C10 have been obtained by the one-pot method of formation of long-chain hydrocarbons, namely, by the telomerization reaction of 1,3-dienes with nucleophiles catalyzed by palladium complexes. A heterogeneous palladium-zeolite catalyst has been used for the first time in telomerization of isoprene with piperidine.Moscow University Chemistry Bulletin 09/2007; 62(5):276-280. -
Article: Effect of 1,1,5-trihydroperfluoropentanol on the structure of unoriented poly(ɛ-caproamide) films
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ABSTRACT: A change in the X-ray patterns of unoriented poly(ɛ-caproamide) films cast from poly(ɛ-caproamide) solutions in formic acid in the presence of 1,1,5-trihydroperfluoropentanol has been examined. It has been shown that the polyfluorinated alcohol increases the proportion of polymer molecules in the planar trans conformation owing to their transition from the gauche conformation constituting the amorphous phase and facilitates formation of hydrogen-bonded layers of macromolecules oriented perpendicular to the film plane.Polymer Science Series B 07/2007; 49(3):70-74. · 0.56 Impact Factor