Ukrainian Chemistry Journal

Contents of Volume 82 № 1 (2016)

Editorial board’s column

FRITSKY I.O., PAVLISHCHUK A.V., GOLENYA I.O., SAFYANOVA I.S.
Structural types of hydroxamate metallacrowns
  • Summary: In this review we discuss a comparatively new class of polynuclear complexes, coordination analogues of crown ethers — metallacrowns. This class of coordination compounds is being intensively investigated due to the whole range of their non-trivial properties (i.e. magnetic, luminescent and sorption). This could allow the following usage of metallacrowns for the multifunctional materials creation. The general structural features of different types of hydroxamate-based metallacrowns are described in review.
  • Keywords: metallacrowns, structural types, hydroxamic acids, polynuclear complexes.
  • pp.: 3 - 16

Inorganic and Physical Chemistry

KOBYLIANSKAYA S.D., LINOVA B.O., KOVALENKO L.L., BELOUS A.G.
Synthesis and investigation of the electrophysical properties of the Li0.33La0.57–хВіхTiO3 system
  • Summary: Based on lithium-lanthanum-bismuth titanate Li0.33La0.57–хВіхTiO3 (0 x 0.1) had been synthesized system of solid solutions with the structure of the defect perovskite by solid-phase reaction. It is found that the solid solution with a perovskite structure are formed in the range 0 x 0.07. It is shown that a partial replacement of La3+ ions by Bi3+ ions in the system Li0.33La0.57–хВіхTiO3 (x=0—0.03) reduces the overall resistance and increases ionic conductivity. The maximum value of the ionic conductivity and the minimum value of the resistance is achieved when x=0.03. Further increasing the concentration of bismuth leads to an increase of resistance and lowering the ionic conductivity.
  • Keywords: lithium conductors, defect perovskite, lithiumlanthanum titanate, method of solid-phase reactions.
  • pp.: 17 - 21

STOYANOVA I.V., CHIVIREVA N.A., EREMIN O.G., ZINCHENKO V.F., ANTONOVICH V.P.
Estimation of oxide admixtures contents in lead (II) fluoride by diffuse reflectance spectroscopy method
  • Summary: Diffuse reflectance spectra (DRS) of industrially produced specimens of PbF2 and model systems based on PbF2 and PbO mixtures annealed in helium medium with the various ratio of components are studied. Possibility of estimation of oxygencontaining admixtures contents calculated relating on Pb2OF2 (wt. %) in materials based on lead (II) fluoride using nondestructive DRS method is established. The equation of the dependence of the magnitude of F(R) (Kubelka– Munk function) from the contents logarythm of Pb2OF2 at 250nm has a linear character. It is established that especially purified PbF2 contains Pb2OF2 up to 1.8wt.%. For confirming presence of oxygen-containng admixtures in PbF2 based materials method of establishing stoichiometry for basic components is used.
  • Keywords: lead fluoride, lead oxofluoride, diffuse reflectance spectroscopy.
  • pp.: 22 - 26

KHALYAVKA Т.А., CAMYSHAN S.V., TCYBA N.N.
Physico-chemical and photocatalytic properties of composite samples based on titanium dioxide and strontium titanate
  • Summary: Mesoporous composite samples of SrTiO3/TiO2 were obtained. Pore volume and specific surface area of the samples are decreasing and pore radius samples showed higher photocatalytic activity in the destruction of organic dyes, compared with pure TiO2 and SrTiO3, which can be explained by an increase in the generation of electron–hole pairs and free radicals involved in the photocatalytic process, as well as the suppression of recombination of photogenerated electrons and holes at the interface SrTiO3 and TiO2.
  • Keywords: titanium dioxide, strontium titanate, photocatalysis, dyes.
  • pp.: 27 - 30

ROIK N.V., BELYAKOVA L.A., DZYAZKO M.A., ORANSKAYA Ye.I.
Design of pH-sensitive supramolecular structures on the outer surface of MCM-41 type mesoporous silicas
  • Summary: Chemical immobilization of N-[N’-(N’-phenyl)-2-aminophenyl]-aminomethyl and N-[N’-(N’-phenyl)-2-aminophenyl]-3-aminopropyl groups on the outer surface of silica particles of MСM-41 typewas realized by chemical assembly method. Introduction of aromatic amino groups in the surface layer of silica was confirmed by IR spectral and chemical analysis of surface substances. Using X-ray diffraction and low-temperature nitrogen adsorption-desorption it was proved that selective post-synthetic modification of MCM-41 surface does not lead to the destruction of hexagonally ordered pore structure. Protolytic properties of grafted aromatic amino groups were studied by potentiometric titration method. It was found that basicity of aromatic amino groups of MCM-41 type mesoporous silica surface increases in the presence of b-cyclodextrin. Obtained results demonstrate the ability of chemical design of pH-controlled nanovalves on the surface of ordered mesoporous matrices.
  • Keywords: MCM-41, surface aromatic amino groups, b-cyclodextrin, protolytic properties
  • pp.: 31 - 39

Electrochemistry

PIRSKYY Yu.K., PANCHISHYN T.N., BARANOVSKАYA O.R.
Oxygen reduction electrocatalysts based on tungsten carbide with 3d-metals
  • Summary: Based on tungsten carbide modified with metallic nanoparticles of 3d-metals (Ni, Co, Fe, Zn, Cu and Mn) nanodisperse composites catalytically active in the reaction of oxygen electroreduction have been synthesized. With the aid of a gas diffusion floating electrode their electrochemical characteristics in 0.5M H2SO4 solution, which simulates the acidic medium of the fuel cell with a proton-exchange membrane have been studied. It has been found that composite WC-electrocatalysts with cobalt and iron have the highest activity in the oxygen reduction reaction.
  • Keywords: oxygen electroreduction, electrocatalysis, electrocatalysts, composites, tungsten carbide, synthesis.
  • pp.: 40 - 44

KOZIN V.F., BLIZNYUK A.V.
The electroreduction of titanium complexes
  • Summary: The laws governing the electroreduction of titanium complexes have been established. On metals with high hydrogen overpotential, deposition ceases and hydrogen evolution begins after titanium deposition and the formation of a sound coating 2–5 mm in thickness. A mechanism of Ti4+ and Ti3+ ion charge exchange during electrode processes is proposed. The dependence of titanium deposition on cathodic materials: Cd, Tl, In, Sn, Bi, Sb, Fe, which differ in nature, on hydrogen overpotential and zero-charge potential is shown.
  • Keywords: electroreduction of titanium, kinetics, reaction mechanism, voltammetry.
  • pp.: 45 - 51

Chemistry of High-Molecular Compounds

FAINLEIB A.M., GUSAKOVA K.G., LAVRENYUK N.S.
Interaction of dicianate ester of bisphenil E with aniline
  • Summary: The present work discloses the chemistry of interaction between the reactive groups of dicyanate ester of bisphenol E and aniline resulting in generation of diylbis(4,1-phenylene)bis(phenylcarbamimidate) ethane. Chemical structure of the reaction product has been confirmed using FTIR and 1H NMR spectroscopies. The yield of the product around 84% after synthesis carried out at 30оC for 1 h has been found. The resulting product can be used as a model of grafting fragment of amino-functionalized nanofillers of different nature to polycyanurate network during synthesis of nanocomposites including sol–gel technique.
  • Keywords: dicyanate estor of bisphenol E, aniline, FTIRspectroscopy, 1H NMR-spectroscopy, diylbis(4,1-phenylene) bis(phenylcarbamimidate)ethane.
  • pp.: 52 - 58

BEY I.N., DENISENKO V.D., NESTERENKO G.M., SLISENKO O.V., BUDZINSKAYA V.L.
Thermal and mechanical properties of urethane-silicate polymer composites with different concentration of inorganic component
  • Summary: Organic-inorganic composites (OIC) based on soft-chain isocyanate oligomer and water-soluble sodium silicate were synthesized. Effect of the organic to inorganic components ratio on thermal and mechanical properties of the obtained OIC was investigated.
  • Keywords: organic-inorganic composites, thermal properties.
  • pp.: 59 - 64

   

   

   

   

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