[en] The composition and stability of peroxomolybdates formed in an aqueous medium at different solution acidity have been determined and their absorption spectra investigated. A complex containing a single peroxogroup may contain an anion of the medium. A complex with two peroxogroups does not contain an anion of the medium and is always characterized by an absorption band at 30.000 cm^-1 (epsilon=1200) regardless of the composition of the medium. The absorption spectrum of complex I reveals a band with a molar absorption coefficient of the order of 350-500, whose position varies from 24.600 to 30000 cm^-1, depending on the composition of the medium. The equilibrium constant of the formation of the monoperoxocomplex k₁=[I]/[Mo][H₂O] varies from 8x10² to 4-5x10³ mol^-1, depending on the composition of the medium

No abstract available

[en] A study was made on kinetics of nitrobenzene hydrogenation to phenylhydroxylamine in dimethylformamide solutions of rhenium thiocomplexes. The mechanism of hydrogenation was suggested. Formation of hydride catalyst complex represents the first stage of the process. Kinetic equation derived on the basis of suggested mechanism corresponds satisfactorily with experimental results. Thermodynamic parameters of separate process stages calculated on the basis of equilibrium constant values testify as well to the benefit of suggested mechanism

[en] A study was made on kinetics of nitrobenzene hydrogenation to phenylhydroxylamine in dimethylformamide solutions of rhenium thiocomplexes. The mechanism of hydrogenation was suggested. Formation of hydride catalyst complex represents the first stage of the process. Kinetic equation derived on the basis of suggested mechanism corresponds satisfactorily with experimental results. Thermodynamic parameters of separate process stages calculated on the basis of equilibrium constant values testify as well to the benefit of suggested mechanism

No abstract available

No abstract available

[en] Catalysts produced by the interaction of VOCl₃ with Aerosil surface hydroxyl groups are studied. It is found that the structure that comprises one ion V⁴⁺ and 3-4 ions V⁵⁺ has the maximum rate of maleic anhydride formation during n-butane oxidation

[en] The state of molybdenum (6) complexes with hydroxyquinoline (oxine) and hexamethylphosphotriamide in reaction mixture in the processes of direct and catalytic epoxidation of cyclohexene and allyl chloride is studied. It is established that direct epaxidation of cyclohexene with diperoxocomplex MoO⁴ oxine² or its catalytic epoxidation with hydroperoxide of tert. butyl in presence of MoO² oxine² complex is realized with ligand (oxine) retention in the inner coordination sphere of molybdenum. Comparison of initial reaction rates under conditions of ligand retention in the composition of complexes has shown that the rate of direct epoxidation with diperoxocomplexes, containing the ligands mentioned, is almost two orders lower the rate of catalytic epoxidation of cyclohexene with tert. butyl hydroperoxide in the presence of the same complex

[en] Photocatalytic activity of graft and supported vanadium oxide catalysts in the reaction of isobutylene oxidation, taking place under conventional conditions with the formation of incomplete oxidation product, is detected. It is ascertained, that supported vanadium catalysts have a higher specific and atomic photocatalytic activity, as compared with grafted ones. It is shown, that in the process of UV irradiation in the reaction medium active centres, which can conduct the reaction in obscure conditions, are formed

[en] The effect of conditions of rhenium heptasulfide synthesis by thiosulfate method on its physicochemical and catalytic properties during hydrogenation of nitrobenzene and m-nitrobenzoic acid has been studied. It is shown that the maximum yield of m-aminobenzoic acid can be attained on insoluble sulfide rhenium contacts, containing excessive amount of sulfur (3.5 %). Under certain conditions of catalyst synthesis particles of Re₂S₇ soluble in dimethylformamide are formed, which possess selectivity towards amine