Effect of the iron content on the properties of a zirconium dioxide catalyst in the hydrogenation of carbon monoxide

The hydrogenation of Co on zirconium dioxide catalysts containing from 0 to 10 mass % iron was studied. Small additions of iron up to about 0.5 mass % promote the ZrO₂ catalysts relative to the formation of C₂–C₄ olefins. In the presence of large iron additives, the catalyst operates as a complex metal-oxide system featuring interaction of its components. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, 252039 Kiev, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 3, pp. 153–158, May–June, 1997.     

Active intermediates in the oxidative bromochlorination of olefins in concentrated hydrochloric acid

A study was carried out on the oxidative bromochlorination of olefins in the presence of KBr using hydrogen peroxide and an electrochemical technique. Asymmetric trihalide anions, Br₂Cl⁻ and BrCl₂ ⁻, were found to be the active bromochlorination reagents. The reaction mechanism was discussed. Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Murmanskaya St., 253660 Kiev-94. Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 4, pp. 248–251, July–August, 1997.     

Reactivity of macroheterocycles with respect to sulfamic acid

It has been established, on the basis of the formation of a 1∶1∶1 inclusion compound of 18,19-benz-1,16-diaza-4,7,10,13-tetraoxoeicosa-17,20-dione with sulfamic acid and water from the interaction of 11–20-membered macrocyclic oxyethyleneamides of phthalic acid with sulfamic acid, that 18–20-membered oxyethylene macrocycles containing six oxygen donor atoms in the macrocycle are effective in the formation of “host-guest” complexes. Physicochemical Institute for the Preservation of the Environment and Mankind, Ministry of Education and Ukraine National Academy of Sciences of Ukraine, Odessa 270100. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1571–1573 November, 1997.     

Energetic and structural characteristics of N-substituted carbazoles and diphenylamines as components of charge transfer complexes

Geometric, spatial, and energetic characteristics of unsubstituted and some N-alkyl substituted diphenylamines and carbazoles as components of charge transfer complexes have been investigated using semi-empirical quantum mechanical modelling. L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, 70 R. Lyuksemburg ul., Donetsk 340114, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 34, No. 2, pp. 79–81, March–April, 1998.     

Ferrocene-containing ligands in the self-assembly of trinuclear μ3-oxocentered carboxylate complexes of chromium(III, III, III)carboxylate complexes of chromium(III, III, III)

New trinuclear μ₃-oxocentered chromium(III, III, III) complexes were obtained by the self-assembly of ferrocenecarboxylate ligands and the Cr₃O fragment. The complexes were investigated by fast-atom bombardment (FAB) mass spectrometry, cyclic voltammetry, and electronic and IR spectroscopy. V. I. Vernadskii Institute of General and Inorganic Chemistry, National Academy of Sciences of Ukraine, 32/34 Prospekt Akademika Vernadskogo, Kiev 03142, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 36, No. 4, pp. 233–237, July–August, 2000.     

Synthesis and properties of inclusion compounds: Zeolites containing encapsulated transition-metal complexes

Published data and original results are surveyed on the synthesis, structure, and properties of a new type of inclusion compounds based on porous substances (zeolites) containing encapsulated transition-metal complexes. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 4, pp. 199–214, July–August, 1999.     

Influence of reactant structure on composition and stability of adducts of bis-macrocyclic complexes of copper(II) with aliphatic α,ω-diamines

On the basis of spectrophotometric measurements, constants have been determined for adduct formation between bis-macrocyclic complexes of copper(II) and aliphatic diamines. For these systems, the influence of reactant structure on the specific features of complexation has been established. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of the Ukraine, 31 Nauka Prospect, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 2, pp. 83–87, March–April, 1997.     

Chemisorption and oxidative decomposition of pyridine on hydrated manganese dioxide

An experimental study using IR spectroscopy and TPSR techniques showed that the extensive oxidation of pyridine on the surface of hydrated manganese dioxide in a two-step adsorption-catalytic mode proceeds through the formation of complexes of the heterocycle with Lewis acid sites. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 03039, Ukraine. Translated from Teoreticheskaya i éksperimental'anaya Khimiya, Vol. 36, No. 2, pp. 101–104, March–April, 2000.     

Role of dimethylformamide in generating the active form of platinum for catalyzing the synthesis of diaryls from aryl iodides

A mechanism is proposed for the reaction of aryl iodides with platinum(II) tetrachloride complexes in dimethylformamide including formation of PtCl₃(CONMe₂)²⁻ in the first step through activation of a dimethylformamide C−H bond by platinum(II) and subsequent oxidative addition of ArI to this species. L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, 70 Lyuksemburg ul., Donetsk 340114, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 34, No. 4, pp. 244–246, July–August, 1998.     

Influence of encapsulation on the mechanism of thermal decomposition of hexacyanotransition metal complexes

It has been established that, in contrast to the pure substances, the thermal decomposition of hexacyanotransition metal complexes, encapsulated in the large cavities of faujasite, occurs by a hydrolytic mechanism. The composition of the gaseous products of the thermal decomposition depend on the characteristics of the localization of the cations in the inclusion compounds. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 2, pp. 107–112, March–April, 1999.     

Investigation of the structure of polyurethanes cross-linked with the ions of divalent 3d metals by a paramagnetic probe method

Polyurethanes cross-linked with Ni(2+), Cu(2+), and Zn(2+) ions were studied by ESR with two types of paramagnetic probes, 2,2,6,6-Tetramethylpiperidin-1-oxyl and copper ethylacetoacetate were used as probes. The different effects of close d-metal ions on the macrocharacteristics of the ion-linked polyurethanes may be due to the formation of additional complexes of the metal ion with the macroligands. Institute of the Chemistry of High-Molecular Compounds, National Academy of Sciences of Ukraine, 48 Khar'kovskoe Shosse, Kiev 02160, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 36, No. 2, pp. 90–94, March–April, 2000.     

Adsorption and kinetics of the oxidation of ethylene on PdCl2/SiO2

A new variant of the kinetic distributive method was used to study the kinetics of the oxidation of ethylene by PdCl₂ complexes supported on silica gel taking account of the equilibrium distribution of ethylene between the gas phase, silica gel, and metal complex reaction sites. Mono-, bi-, and polynuclear palladium(II) species are found to participate in the reaction. The Pd^II activity increases with increasing amount of nuclei in the species. L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, 70 R. Lyuksemburg ul., Donetsk 83114, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 36, No. 4, pp. 243–246, July–August, 2000.     

The effect of encapsulated cyanide complexes on the localization of cations in faujasite

Features of the localization of various types of cations and their distribution between the structural elements of the framework of faujasite with encapsulated hexacyanide complexes of iron(II) and cobalt(III) were established. The content of the alkali-metal cations in the sodalite cells is increased compared with faujasite, and the cations of the transition metals are localized in the large cavities with the formation of Me(S_II)−NC−Fe(CN)₅ (Me=Cu, Co) and (NC)₅Fe−CN−Me(S_V)−NC−Fe(CN)₅ (Me=Ni, Cu, Co) fragments. L. V. Pisarzhevskii Institute of Physical Chemsitry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 35, No. 1, pp. 56–61, January–February, 1999.     

Separation of C1–C4 hydrocarbon gases on impregnated liquid membranes

Diffusion plays an important role along with complexation in the separation of C₁–C₄ hydrocarbon gases on copper-containing impregnated liquid membranes. The partition factor changes as the process goes from nonsteady-state to steady-state. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 34, No. 3, pp. 191–195, May–June, 1998.     

Chemisorption of N-vinyl-2-pyrrolidone on the surface of hydridosilica gel

The solid phase hydrosilation of N-vinyl-2-pyrrolidone by≡Si−H bonds immobilized on a silica gel surface has been investigated. Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252022, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 4, pp. 236–239, May–June 1999.     

The role of the geometric factor in the selective oxidation of lower paraffins at VPO catalysts

For the most widely published oxidation of n-butane at vanadium-phosphorus catalysts it was shown that the geometric factor plays a deciding role in the formation of the selective oxidation products. The mechanism proposed for the transformation of the paraffin at the [100] plane of the vanadyl pyrophosphate, which takes account of the geometry of the molecule being oxidized, explains the observed experimental facts, i.e., the increase in the oxidation rate with increase in the effective negative charge at the oxygen atoms of the catalyst, the positive effect of the hyperstoichiometric phosphorus on the selectivity of oxidation, the increased selectivity of oxidation with the introduction of additives that form phosphates, and the difference in the characteristics and mechanism of the oxidation of a paraffin and C₄ olefins. On the basis of the proposed mechanism suggestions are made about possible paths for the transofrmation of C₂−C₆ paraffins at VPO catalysts and the factors that could affect the selectivity of these processes. A number of the suggestions were confirmed by the author's own investigations and by published investigations. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 5, pp. 265–276, September–October, 1999.     

The α-effect of oximate ions and solvent effect in the transfer of the toluenesulfonyl group in aqueous dimethylsulfoxide

The kinetic behaviour of oximate ions was studied in the transfer of the toluenesulfonyl group in aqueous dimethylsulfoxide (0–95 vol.% DMSO). The solvation effects of the solvent are a factor controlling the nucleophilicity and magnitude of the α-effect of the oximate ions. L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, 70 R. Lyuksemburg ul., Donetsk 340114, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 36, No. 1, pp. 30–35, January–February, 2000.     

Investigation of the mechanism of methane formation in the fischer-tropsch synthesis on a Co/SiO2·ZrIV catalyst

Methane is formed in the Fischer-Tropsch synthesis under real conditions both through intermediates leading to chain propagation and by hydrogenation of surface carbon. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, Prospekt Nauki 31, 252039 Kiev, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, No. 1, pp. 41–43, January–February, 1996.     

α-Effect of hydroxylamine in the transfer of a toluenesulfonyl group in water—Dimethyl sulfoxide mixtures

A kinetic and thermodynamic analysis of the reactions of hydroxylamine with aryltoluenesulfonates in H₂O-DMSO mixtures (0–90 vol.% DMSO) indicated that the neutral and anionic forms of hydroxylamine are strong α-nucleophiles, and the magnitude of the α-effect shows an asymmetric bell shape depending on the DMSO content. This phenomenon is interpreted. L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, 70 R. Lyuksemburg ul., Donetsk 340114, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 2, pp. 83–88, March–April, 1999.     

Application of topological indexes to predict immunomodulating activity of new peptides

The application of topological indexes to codify the structures of peptide immunomodulators — analogs of taftsin — and to predict the pharmacological activity of new compounds by the κ-neighbor and neural network methods is described. It is shown that if the conformational state of the model compound is chosen correctly, topological indexes can be used successfully for effective screening in the development of new medicinals with corresponding mechanisms of action. Institute of Bioorganic Chemistry and Petrochemistry, Ukraine National Academy of Sciences, Ukraine, 252660 Kiev-94, 1 Murmanskaya Ulitsa. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 2, 100–104, March–April, 1997.