The effect of chemical modification on the chromatographic properties of polymeric adsorbents polysorb-1 and hisep Q and the diatomite carrier chromosorb P NAW

Polytrimethylsilylpropyne with the decomposition temperature 205°C was synthesized and characterized. The effect of chemical modification by polytrimethylsilylpropyne on the gas chromatographic properties of polymeric adsorbents and the diatomite carrier for the selective separation of C₁–C₁₀ hydrocarbons, alcohols and aromatic and sulfur-containing compounds was studied. Original Russian Text ? E.Yu. Yakovleva, V.Yu. Belotserkovskaya, V.P. Fadeeva, G.S. Litvak, E.A. Paukshtis, D.E. Babushkin, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 5, pp. 972–977.     

H+-Cu2+ ion exchange on a Cu0-KU-23 sulfocation exchanger nanocomposite in solutions with various pH values

The influence of solution pH on H⁺-Cu²⁺ exchange equilibrium was studied for the disperse copper- KU-23 (15/100 S) macroporous strongly acid sulfocation exchanger nanocomposite. In dilute solutions of copper(II) sulfate in weakly acid media (pH 3–6), ion exchange limitation is related to the consumption of hydrogen counterions and the formation of copper counterions in a side reaction between copper particles and impurity oxygen. The concentration of hydrogen counterions in the nanocomposite is replenished as pH decreases because of their sorption from solution together with copper ions. Original Russian Text ? E.V. Zolotukhina, T.A. Kravchenko, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 5, pp. 934–938.     

The specific surface area and porous structure of graphite materials

Transformations of the specific surface area and porous structure of carbon materials based on graphite were studied by low-temperature adsorption of nitrogen. Exfoliated graphite and graphite foil were found to have a developed (compared with the initial graphite) surface (up to 90 m²/g) and a porous structure formed by slit-like mesopores with a characteristic radius of ∼20 ?. The determining influence of the method of synthesis on the adsorption properties of materials was demonstrated for the first time. Original Russian Text ? O.N. Shornikova, E.V. Kogan, N.E. Sorokina, V.V. Avdeev, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 6, pp. 1161–1164.     

A novel route for the synthesis of composite dielectric core/silver shell particles

We demonstrated the possibility of preparing continuous silver shells on particles of polystyrene latex by enlarging adsorbed seeding metal nanoparticles in solution containing ascorbic acid and silver nitrate. It is shown that a strong batochromic shift of the maximum of surface plasmon resonance is observed for such composite structures. Original Russian Text ? O.V. Dement’eva, M.A. Filippenko, M.E. Kartseva, V.M. Rudoy, 2009, published in Kolloidnyi Zhurnal, 2009, Vol. 71, No. 4, pp. 569–571.     

The electrical conductivity of poly-p-xylylene + CdS nanocomposites

The dependence of electrical conductivity on the concentration of CdS (c) and temperature (T) over the temperature range 10–300 K was studied for poly-p-xylylene-CdS (PPX + CdS) nanocomposites prepared by solid-state cryochemical synthesis. The results were discussed in terms of the heterogeneous conductivity model including various charge transfer mechanisms in various nanocomposite regions. Under the illumination of a film with c > 11 vol % by a daylight lamp, the conductivity increased, and the σ(T) dependence was metallic in character at low temperatures. The photoconductivity of films at larger concentrations c was caused by the appearance of photoexcited electrons in CdS nanoparticles, the separation of charges at the nanoparticle-matrix boundary, and percolation effects in films. The PPX matrix was shown to actively participate in electrical conductivity; electrons in this matrix jumped between phenyl rings. The experimental dependence of dark conductivity σ(T) at temperatures from 150 to 300 K was analyzed using the Mott hopping conductivity model with variable jump lengths. The main points of the Mott theory of hopping conductivity were discussed. Original Russian Text ? I.A. Misurkin, S.V. Titov, T.S. Zhuravleva, I.V. Klimenko, S.A. Zav’yalov, E.I. Grigor’ev, S.N. Chvalun, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 3, pp. 534–540.     

The photochromic properties of indoline spirooxazine-thermoplastic polymer systems obtained by supercritical fluid impregnation

The impregnation of thermoplastic polymers (polyethylene, polypropylene, polymethyl methacrylate, and polycarbonate) with photochromic compounds from the class of indoline spirooxazines in supercritical carbon dioxide (SC-CO₂) was studied. The concentration of the photochrome and the kinetics of decolorization of its colored form depended strongly on the type of the polymer matrix and the structure of spirooxazine. The introduction of 1,3′,3′-trimethylspiro(indoline-2′,3-3H-anthraceno[2,1-b][1,4]oxazine) (SAO) into polycarbonate caused anomalous stabilization (the prolonged conservation of the excited colored form of SAO in the polymer matrix). In contrast to other photochrome-polymer pairs, after supercritical impregnation into polycarbonate, at least 10% of all SAO molecules were in the colored form, which was highly stable and did not decolorize after 150 days; the rest of the impregnated SAO molecules were localized in the matrix as individual molecules, partially colorized after matrix relaxation, or nanocrystals of characteristic sizes ∼10–20 nm. The mechanisms of the anomalous stabilization of the colored SAO form in the polycarbonate matrix are discussed. Original Russian Text ? N.N. Glagolev, A.B. Solov’eva, A.V. Kotova, V.T. Shashkova, B.I. Zapadinskii, N.L. Zaichenko, L.S. Kol’tsova, A.I. Shienok, P.S. Timashev, V.N. Bagratashvili, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 5, pp. 985–992.     

The physicochemical properties of micro/mesoporous materials prepared by the recrystallization of zeolite BEA

Micro-mesoporous materials with various ratios between micro- and mesopores were prepared by the recrystallization of zeolite BEA in an alkaline medium in the presence of cetyltrimethylammonium bromide. The materials were characterized by X-ray diffraction, low-temperature nitrogen adsorption, and IR spectroscopy. Recrystallization under mild conditions did not cause substantial changes in the number of acid centers but increased the accessibility of acid centers to large-sized molecules because of the creation of mesopores. An increase in the degree of recrystallization caused first partial and then complete zeolite transformation into MSM-41 mesoporous aluminosilicate, which was accompanied by a decrease in the number of acid centers. The IR spectra were used to determine the diffusion coefficients of cumene in the initial and recrystallized samples. Recrystallization increased the diffusion coefficient by 3–4 times. Original Russian Text ? V.V. Ordomskii, Yu.V. Monakhova, E.E. Knyazeva, N.S. Nesterenko, I.I. Ivanova, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 6, pp. 1150–1155.     

The dynamics of reductive sorption of oxygen by a granular bed of electron-ion exchangers with different copper dispersities

The behavior of an immobile granular sorbent bed in one-component sorption in a column reactor is described in terms of the kinetic model of redox sorption taking into consideration the dispersity of metal particles, their radial distribution, peculiarities of chemical oxidation, and the relation of the overall rate of the process to the properties of the ion exchange matrix. The mathematical problem is formulated and solved numerically; the solution is analyzed theoretically in relation to the basic parameters of the sorption system. A satisfactory agreement is obtained between the experimental and calculated data on the reductive sorption of molecular oxygen from water on a copper-containing electron-ion exchanger. Original Russian Text ? D.V. Konev, T.A. Kravchenko, A.I. Kalinichev, E.S. Kipriyanova, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 5, pp. 948–953.     

Kinetics and mechanism of nickel reaction with benzyl bromide in dimethylformamide

Abstarct  The reaction of nickel with benzyl bromide in DMF has been studied. The reaction intermediates were investigated by different methods and the kinetic and thermodynamic parameters were determined. The reaction of benzyl bromide with nickel was shown to occur on the metal surface by the Langmuir-Hinshelwood scheme, with the formation of benzyl radicals which are recombined and isomerized in solution to form 1,2-diphenylethane and trace amounts of 4.4′-dimethylbiphenyl. Original Russian Text ? A.M. Egorov, S.A. Matyukhova, I.S. Kocherova, A.A. Novikova, A.V. Anisimov, 2009, published in Zhurnal Obshchei Khimii, 2009, Vol. 79, No. 3, pp. 455–463.     

The standard enthalpies of formation of 4,4′-dinitrodiphenyl ether

The energy of combustion and the standard enthalpy of formation of 4,4′-dinitrodiphenyl ether were determined experimentally for the first time. Original Russian Text ? S.V. Mel’khanova, S.M. Pimenova, I.A. Nesterov, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 7, pp. 1399–1400.     

The complex formation properties of 18-crown-6-2-styrylbenzothiazole and the product of its photocyclization

Complex formation of 18-crown-6-2-styrylbenzothiazole and a crown-containing benzothiazolquinoline derivative with alkaline earth metal perchlorates was studied. The structures and stability constants of the complexes were determined. Original Russian Text ? O.A. Fedorova, E.N. Gulakova, I.E. Lobazova, Yu.V. Fedorov, N.E. Shepel’, L.G. Kuz’mina, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 6, pp. 1178–1182.     

Comparative evaluation of magnetite dissolution efficiencies of EDTA and OEDP aqueous solutions

The influence of EDTA and OEDP on the magnetite dissolution rate in various experimental conditions was studied. From a comparative analysis of rate data in commensurate conditions, EDTA is a more efficient complexone than OEDP. The effect of both the nitrogen-bearing and the phosphorus-bearing complexones was to change the potential at the oxide/solution interface. The potential-controlling reaction was recognized as Fe^IIIY⁻ + H⁺ + e = Fe^IIHY⁻. Original Russian Text ? I.G. Gorichev, I.V. Artamonova, E.E. Nifant’ev, E.O. Zaben’kina, V.V. Kurilkin, N.A. Kishkina, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 5, pp. 869–880.     

Solvent effects on the formation and absorption spectra of nanodisperse molybdenum disulfide

The optical absorption spectra of molybdenum disulfide prepared by monolayer dispersion of a crystalline precursor in a liquid medium were studied. On the whole, the three-dimensional structure of the crystalline analogue was reconstructed in disperse MoS₂ dried to a powder state. A substantial fraction of the material transformed into a nanosized state during dispersion and was stabilized in the form of nanoparticles in various solvents. The stabilizing action of the solvents studied decreased in the series acetonitrile, ethanol > chloroform > water. The data on the optical absorption of MoS₂ suspensions in various solvents were evidence of a broad particle-size distribution. Along with nanoscale particles, the samples contained larger particles responsible for long-wave absorption (>600 nm). The size of nanoparticles was estimated using an empirical correlation between the position of maximum A (the long-wave maximum of the first allowed absorption band) in the absorption spectrum and the size of particles (2R). This correlation was obtained using the literature data on monodisperse particles and mixtures of particles. The number of particles showed a tendency to increase as the concentration of disperse MoS₂ in acetonitrile decreased. Original Russian Text ? I.V. Klimenko, A.S. Golub’, T.S. Zhuravleva, N.D. Lenenko, Yu.N. Novikov, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 2, pp. 346–350.     

Proton magnetic relaxation in aromatic polyamides during water vapor sorption

The state of the components in the aromatic polyamide-water system was studied by NMR and sorption. A comparative analysis of spin-lattice and spin-spin relaxation in aromatic para-polyamide (para-aramid) technical fibers Rusar, Kevlar, and Technora was performed depending on the sorption value. The NMR results correlated with the supramolecular structure of polymers and quasi-chemical equation parameters for water vapor sorption. Original Russian Text ? T.V. Smotrina, Yu.S. Chulkova, D.V. Karasev, N.P. Lebedeva, K.E. Perepelkin, S.F. Grebennikov, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 7, pp. 1346–1351.     

Structure and proton donating ability of 2- and 2,5-bis(1-trifluoromethanesulfonylamido-2,2,2-trichloroethyl)pyrroles

2-(1-Trifluoromethanesulfonylamido-2,2,2-trichloroethyl)pyrrole and 2,5-bis(1-trifluoromethanesulfonylamido-2,2,2-trichloroethyl)pyrrole according to quantum chemical calculations (B3LYP/6-311G**) exist in the isomeric forms whose structure determines the formation of intramolecular hydrogen bonds NH⋯Cl, NH⋯O=S and CH⋯O=S of different strength. Potentiometric and spectroscopic acidity of these compounds is determined. From the data of IR spectroscopy their proton donating ability upon interaction with Lewis bases is shown depending on the presence of intramolecular hydrogen bonds, mutual effects of intermolecular hydrogen bonds formed by the sulfonamide and pyrrole NH groups with the base, and electronic effects of the substituents. Original Russian Text ? L.P. Oznobikhina, N.N. Chipanina, B.A. Shainyan, L.V. Sherstyannikova, V.A. Kukhareva, T.N. Aksamentova, E.V. Kondrashov, G.G. Levkovskaya, 2009, published in Zhurnal Obshchei Khimii, 2009, Vol. 79, No. 2, pp. 326–333.     

The thermodynamics of benzene adsorption on carbon obtained by the pyrolysis of hypercrosslinked polystyrene

The Glukauf chromatography method was used to study the adsorption of benzene on a microporous carbon material prepared by the pyrolysis of hypercrosslinked polystyrene. The thermodynamic characteristics of adsorption were determined as functions of the degree of pore filling. Over the range of relative pressures studied (<0.005), adsorption was shown to occur in ultramicropores by the mechanism of primary filling without condensed phase formation. Original Russian Text ? L.D. Asnin, V.A. Davankov, A.V. Pastukhov, K. Kaczmarski, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 7, pp. 1356–1359.     

The standard enthalpies of formation of 1-nitrodispiro[2.0.2.1]heptane and 1-nitrodispiro[2.0.3.1]octane

The energies of combustion and standard enthalpies of formation of 1-nitrodispiro[2.0.2.1]heptane and 1-nitrodispiro[2.0.3.1]octane were determined experimentally. Original Russian Text ? S.V. Mel’khanova, S.M. Pimenova, N.V. Yashin, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 7, pp. 1396–1398.     

Effects of the degree of substitution on the physicochemical properties and photodynamic activity of zinc and aluminum phthalocyanine polycations

A series of zinc and aluminum phthalocyanines containing 3–8 pyridiniomethyl or cholinyl substituents on average were synthesized. As the number of cation substituents increased, in aqueous solutions, the aggregation ability of phthalocyanines decreased, while the quantum yields of fluorescence and singlet oxygen generation increased. The photodynamic inactivation of coliform bacteria sensitized by zinc and aluminum phthalocyanine polycations with an increase in the substitution degree became more effective. Original Russian Text ? D.A. Makarov, N.A. Kuznetsova, O.A. Yuzhakova, L.P. Savvina, O.L. Kaliya, E.A. Lukyanets, V.M. Negrimovskii, M.G. Strakhovskaya, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 6, pp. 1183–1190.     

The influence of carrier gas pressure on the retention of sorbates on monolithic capillary columns in gas chromatography

The influence of carrier gas pressure on the retention factor k′ of light hydrocarbons C₁–C₄ in a monolithic capillary column based on divinylbenzene was studied. It was shown that, for monolithic columns and nonideal carrier gases, the pressure dependence of lnk′ was nonlinear over a wide pressure range and could be described by the classic Everett equation. It was concluded that the competitive adsorption model failed to describe the experimental data correctly, especially for strongly retained sorbates and/or heavy carrier gases. Original Russian Text ? A.A. Korolev, V.E. Shiryaeva, T.P. Popova, A.V. Kozin, A.A. Kurganov, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 4, pp. 776–783.     

Systems based on A2TeC6 (A = K, Rb, Cs, and Tl(I); C = Br and I) compounds with peritectic interactions

This work presents six peritectic quasi-binary systems based on A₂TeC₆ (A = K, Rb, Cs, and Tl(I); C = Br and I) ternary halides. We consider factors influencing physicochemical interactions between components in these systems. Original Russian Text ? E.Yu. Peresh, V.I. Sidei, O.V. Zubaka, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 2, pp. 360–363.