I. G. Tarkhanova

Distinctive Characteristics of Carbon Tetrachloride Addition to Olefins in the Presence of Copper Complexes with Donor Ligands

The interaction between CCl4and olefins with different structures is studied in the presence of copper complexes with P-, S-, and N-containing donor ligands. Kinetic and spectroscopic studies show that the ability of olefins to be coordinated to copper complexes governs the rate, the product composition, and the reaction mechanism. Depending on the olefin and the structure of the metal complex, either typical radical-chain reactions or processes without free radicals are observed.

Catalysts based on the immobilized complexes of copper with quaternary ammonium bases for chlorination of alkanes with carbon tetrachloride

The complexes of copper chloride with quaternary ammonium bases supported on silica are highly active in the reaction of carbon tetrachloride with decane was found in the presence of an electron donor (ethanol). The effectiveness of the catalysts depends on the method of their deposition onto the support. The catalysts obtained as a result of covalent binding with the surface through the formation of siloxane bonds (immobilization) exhibit high stability and higher activity than the analogues prepared by the impregnation of the support with the catalytic complex. The introduction of ethanol into the reaction system substantially increases the activity and stability of all of the catalysts.

Heterogeneous catalysts based on immobilized copper complexes in the oxidation of mercaptans

Immobilization by covalent bonding of copper complexes with amino alcohols, amino acids, hydroxyalkylpyridine, and quaternary ammonium ionic liquids on the surface of mineral supports makes it possible to prepare heterogeneous catalysts for oxidation of mercaptans. An advantage of these catalysts is the combination of high performance with stability.

The Evolution of Reactive Ligands in the Catalysis of Radical Processes by Copper Complexes

Abstract Two radical reactions (addition of CCl4 to the double bond of oct-1-ene and oxidation of dodecane-1-thiol with air oxygen) catalyzed by copper complexes have been investigated. Various nitrogen-containing compounds (aliphatic and aromatic amines, aminoalcohols, aminoacids) were used as the ligands. In both cases, products of ligand transformation have been observed, products of the transformations have been identified by GLC-MS. In case of the CCl4 addition, the reaction can be initiated by the either copper complex or the ligand. In case of the thiol coupling, the reaction proceeds as a conjugated oxidation of both the thiol and the ligand. A correlation between the donor ability of the ligand and its reactivity has been found. GRAPHICAL ABSTRACT

Immobilized copper- and molybdenum-containing ionic liquids in oxidation of sulfides

The synthesis and comparative analysis of catalytic properties of Cu- and Mo-containing ethylpropylimidazolium derivatives immobilized on silica-series mineral supports have been performed. The oxidation of diethyl sulfide and methyl phenyl sulfide with oxygen and hydrogen peroxide in a hydrocarbon medium has been studied as a model process. The catalyst based on ethylpropylimidazolium polymolybdates is the most active and stable in the oxidation of methyl phenyl sulfide.

Field technology for desulfurization of associated petroleum gas

Applicability of gas desulfurization technologies for sulfur-containing gases under conditions of the limited choice is analyzed. Data on efficiency of a new process for catalytic desulfurization of sulfur-containing gases through H2S and RSH conversion in sulfur and disulfides, respectively, is demonstrated. The technology is approved in pilot projects of gas desulfurization at a flare line, on a gas-processing plant. The equipment is developed and certificated. Installations for catalytic desulfurization are intended to be equipped with a complete set of blocks for gas preparation and power-generating equipment directly at deposits. This solution substantially decreases both capital and operational expenditures compared to the traditional multi-stage absorption/desorption technologies such as expensive Claus process.

Reactions of polyhalomethanes with olefins catalyzed by copper complexes with aromatic amino alcohols

Copper complexes with amino alcohols structurally similar to ephedrin (1-phenyl-3-(N-methylamino)propan-1-ol and 1-phenyl-2-(N-methylamino)ethanol) are catalytically very active in the free-radical addition of CCl4 and CBr4 to linear alk-1-enes. These amino alcohols themselves are initiators of radical addition reactions, and, in the reaction with CBr4, they are more active than the metal complexes. In the presence of the amino alcohols, as distinct from classical radical initiators, the reaction is highly selective and affords an addition product. An analysis of kinetic equations and the data obtained for the reaction involving CHCl3 suggest that the amino alcohols and the corresponding metal complexes are involved in different ways in the addition of CCl4 and CBr4 to linear alk-1-enes.

Catalytic activity of polymetalorganosiloxanes supported on silica in the metathesis of a C-Cl bond

The catalytic activity of structurally different Cu- and Ni-containing polymetalorganosiloxanes supported on silica was studied using the reaction of C–Cl bond metathesis in the carbon tetrachloride–saturated hydrocarbon (n-decane) system as an example. Catalysts with low metal contents were found to exhibit the highest activity; an increase in the metal content resulted in a decrease in both conversion and specific activity. At the initial portions of kinetic curves, the reaction was described by first-order rate equations with respect to n-decane; the reaction was of fraction order with respect to CCl4and catalyst. The activation energy of the process in the n-decane–carbon tetrachloride system on a copper-containing network catalyst was 23 ± 2 kcal/mol. The mechanism of catalysis on immobilized catalysts from the above class is discussed.

Immobilized ionic liquids based on molybdenum- and tungsten-containing heteropoly acids: Structure and catalytic properties in thiophene oxidation

Comparative analysis of heterogeneous catalysts for the peroxide oxidation of thiophene is conducted. The catalysts are imidazole ionic liquids (ILs) containing anions of phosphomolybdic and phosphotungstic acids immobilized on mineral supports. Immobilization is implemented by the covalent bonding of an IL fragment to a silica surface or by adsorption on alumina. The catalysts are active not only in the model oxidation of thiophene in isooctane, but also in the desulfurization of a straight-run diesel fraction and the “synthetic crude oil” derived from oil shale.

Reactive ligands in radical processes catalyzed by copper complexes

The effect of the reactivity of donor ligands on the catalytic properties of copper complexes in the oxidative dimerization of mercaptans is considered. Catalytic compositions containing metal complexes in an excess of organic reagent ligands, which can show pronounced reductive properties (aromatic amines) or, on the contrary, oxidative properties (dimethyl sulfoxide) toward substrates, exhibit the greatest activity. In the course of the oxidation of mercaptans catalyzed by copper complexes, redox reactions accompanied by not only a change in the oxidation state of the metal but also the direct interaction of a substrate with an organic donor occur. In the presence of aromatic amines, the coupled oxidation of thiols and amines occurs, whereas dimethyl sulfoxide participates in the reaction as an oxidizing agent.