Tandem silylation—desilylation reaction in the synthesis of N-methyl carboxamides

Russian Chemical Bulletin - The N-methylation of primary carboxamides is based on two consecutive reactions. The silylation of the corresponding carboxamides with chloro(chloromethyl)dimethylsilane...     

(O-Si)-Chelate acetic and benzoic acid N-(fluorosilylmethyl)amides: synthesis and structure

Russian Chemical Bulletin - New representatives of (O-Si)-chelate compounds, N-(fluorosilyl)methyl derivatives of N-methylacetamide, N-methylbenzamide, N-phenylacetamide, and N-phenylbenzamide,...     

Oxidative Transformations of Ethane and Ethylene on VMoTeNbO Catalysts

Russian Journal of Applied Chemistry - Comparative studies of oxidative transformations of ethane and ethylene were performed on multi-component oxide catalysts of the preset cationic composition,...     

Photocatalytic Properties of Thermally Annealed Films of Titanium Butoxide

Optics and Spectroscopy - We show that titanium dioxide particles capable of reactive oxygen species generation can be produced in titanium butoxide films by annealing them at 500°C. Optimal...     

(Chloromethyl)alkoxyhalogenosilanes in Reaction with N-Trimethylsilyl-N-methylacetamide

Russian Journal of General Chemistry - The reaction of N-trimethylsilyl-N-methylacetamide with polyfunctional silanes, namely methyl(chloromethyl)alkoxychlorosilanes and...     

Detection and quantification of chitosan aggregates by pressure-assisted capillary zone electrophoresis

An approach to the detection and determination of chitosan aggregates in acetic acid solutions is proposed using pressure-assisted capillary zone electrophoresis. Processes of chitosan aggregation are studied depending on the composition of dispersion medium and storage time. The presence of several species of positively charged chitosan aggregates is revealed for the first time. Particle sizes in the range 20–2500 nm are determined by scanning electron microscopy and static and dynamic light scattering. The dependence of the shape of electropherograms on particle size distribution obtained under the same conditions is found. A trend to changing electrophoretic mobility depending on the size of the aggregate is observed, which enables the approximate evaluation of the polydispersity of chitosan solutions. Chitosan is used for the effective dynamic modification of capillaries, which does not require the introduction of a modifier into the background electrolyte.     

Experimental investigation of the interaction of a shock wave with a magnetic field

We present certain results of an experimental investigation of the propagation of a shock wave S through a magnetohydrodynamic channel of the Faraday type. Under conditions of short circuiting of the induced currents in the supersonic stream that follows the shock wave, we registered the occurrence of a shock front T. The x-t diagrams of the motion of the S and T shock waves in the channel and behind it are determined. For a number of fixed sections in the channel, we have measured the density and degree of ionization of the gas and determined their time dependence. The investigations were performed in argon, and the ionizing shock wave propagated with Mach numbers 12–13. The magnetic field intensity was 1.5 T.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 3, pp. 153–183, May–June, 1971.     

Formation and Amplification of Shock Waves in a Bubble “Cord”

The structure and dynamics of the wave field generated by a bubble system in the form of an axial bubble cylinder (cord) excited by a plane shock wave propagating along the axis in an axisymmetric shock tube are numerically examined. It is shown that consecutive excitation of oscillations of the bubble zone results in formation of a quasi-steady shock wave in the cord and in the ambient liquid. Results of the numerical analysis of the maximum amplitude of the resulting wave as a function of problems parameters are described.__________Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 5, pp. 46–52, September–October, 2005.     

Synthesis of N-methyl-N-(silylmethyl)amines

Russian Chemical Bulletin - (Chloromethyl)silanes ClCH2SiMen(OMe)3-n (n = 0—2) react with methylamine at room temperature to give a mixture of secondary N-methyl-N-(silylmethyl)amines...     

Electronic effects of 2-azasilatran-3-one groups

1-Phenyl-2-azasilatran-3-ones have been studied by multinuclear NMR spectroscopy. The π-accepting ability of 2-azasilatran-3-one groups is substantially lower and their σ-donating ability is higher than those of (acetamido)diethoxysilyl groups of the model tetracoordinated compounds.