Oxidation of the [Rh(CO)2Cl2] anion in aqueous solution

The reaction of rhodium(I) carbonyl chloride, [Rh(CO)₂Cl]₂, with dichromate, cerium(IV) sulfate, hexachloroplatinic acid or p-benzoquinone in aqueous hydrochloric acid proceeds by consumption of 4 equivalents of oxidizing agent per mole or rhodium(I) in accordance with the equation Rh^I(CO)₂  4e + H₂O → Rh^III(CO) + 2H⁺ + CO₂A “cyclic” oxidation mechanism is suggested.     

Synthesis of siloxane analogue of polyethylene terephthalate

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Coordination radical polymerization of methyl methacrylate,initiated by the azobis(isobutyronitrile)–tri-<Emphasis Type="Italic">n</Emphasis>-butylborane binary system

A procedure for coordination radical polymerization of methyl methacrylate in the bulk, initiated by the azobis(isobutyronitrile)–tri-n-butylborane binary system at 60°С, was developed. Butyl radicals participating in the initiation step were detected by EPR. These radicals are generated by complexation of cyanoisopropyl radicals with trialkylborane. The radical at the boron atom transforms from the C-centered to N-centered structure with the subsequent S_R2 reaction and fast generation of n-butyl radicals. As found by NMR and confirmed by kinetic studies, the tri-n-butylborane–initiator–monomer system stimulates generation of propagating poly(methyl methacrylate) radicals.     

Parametric analysis of the regimes of shock-wave action on gas-liquid media

The salient features of shock and isentropic action on gas-liquid media are investigated using a wide-range equation of state for water and vapor. The effect of the pressure and the vapor (gas) content on the speed of sound in the gas-liquid mixture is considered. The parameters of incident and reflected wave in the gas-liquid medium are obtained on the basis of the Rankine-Hugoniot relations for the cases of isothermal, adiabatic, and shock compression of the gas component. It is shown that when the Rankine-Hugoniot equations of the shock compression of the mixture are used within the framework of the single-velocity, two-temperature model with the same pressure and under the condition of the additivity-in-mass of the internal energy of the mixture, each fraction is compressed in accordance with its own individual shock adiabat equation. The calculated and experimental data on the acoustic and shock wave propagation in vapor- and gas-liquid media and their reflection from barriers are compared.     

Co-synthesis of 1-(3-aminopyridin-2-yl)-1H-benzimidazole and 3-(2-aminophenyl)-3H-imidazo[4,5-b]pyridine

Russian Chemical Bulletin - A new method for the synthesis of N-substituted 3H-imidazo[4,5-b]pyridine via chemical reduction of 1-(3-nitropyridin-2-yl)-1H-benzimidazole in an acidic media was...