Experimental study of reflection from discrete random inhomogeneities

Acoustic-signal backscattering by fixed discrete inhomogeneities randomly situated on a plane is modeled. The following effects are detected experimentally and discussed: the effect on backscattering intensity of coherent reflection from a weakly reflecting substrate, the collective effect associated with correlation of the scatterer locations, and the effect of multiple scattering with high inhomogeneity concentrations.Nizhny Novgorod State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 36, No. 8, pp. 832–835, August, 1993.     

Electrocatalytic fluoroalkylation of olefins

An efficient nickel-catalyzed method devoted to the direct addition of perfluoroalkyl halides (I, Br) to α-methylstyrene is described. This procedure allows for synthesis of compounds resulting from addition-dimerization in good yields.     

Electrochemical oxidative phosphorylation of azoles in the presence of silver catalysts

A new method for the phosphorylation of benzo-1,3-azoles (benzoxazole, benzothiazole, and 3-methylindole) with diethyl phosphite by electrocatalytic oxidation was proposed. The process occurs under electrochemical mild conditions (room temperature, normal pressure) in the presence of silver salts or silver oxide. This method allows one to obtain 2-phosphorylated products of benzo-1,3-azoles in good yield (up to 75%).     

Electrocatalytic fluoroalkylation of olefins. Perfluoroalkylation of 2-vinylpyridine

Perfluoroalkylation of 2-vinylpyridine was conducted under conditions for the formation of low-valent nickel complexes during electroreduction of NiBr₂L (L is the bipy, terpy) in DMF solutions. Depending on the electrosynthesis conditions, either dimeric products of addition of perfluoroalkyl substituents at the double bond of the olefin or (in the presence of triethylamine) 1-perfluorohexyl-2-pyridinethylene were formed.     

Spin-adduct of the P4 ·− radical anion during the electrochemical reduction of white phosphorus

The radical anion P₄·⁻ was detected and identified by the ESR method as a spin-adduct with nitrone during the electrochemical reduction of white phosphorus in the presence of a spin trap, viz., α-phenyl-N-tert-butylnitrone, in a special electrolysis cell with a helical platinum working electrode in the potentiostatic mode. The character of the behavior of P₄·⁻ and the spin trap during electrochemical reduction was monitored by cyclic voltammetry directly in the electrolysis cell, and the spin-adduct formed was detected by ESR.     

Reactions of N,N'-Dialkylcyclohexane-1,2-diimines with Trivalent Phosphorus Acid Chlorides

N,N'-Dialkylcyclohexane-1,2-diimines react with trivalent phosphorus acid chlorides to give, depending on the structure of the organophosphorus reagent and reaction conditions, either 1,3,2-diazaphospholanes (three-coordinate phosphorus) containing the cyclohexadiene fragment in positions 4 and 5, or 1,3,2-diazaphospholines (four-coordinate phosphorus).     

Quantum-chemical calculation on models of hydroxy-containing zeolite fragments

Fragments of the zeolite structure have been calculated by the EHT method. The results are in agreement with spectral data on structural hydroxy groups of zeolites.

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PMX . .

     

Methanol transformations on zirconium phosphate, CuX zeolite and their mixtures

It has been revealed that the mixtures of CuX zeolite and zirconium phosphate are more active catalysts for the oxidative dehydration of methanol than the individual components.

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