Synthesis of aryl- and heteryl-containing gem-acylnitrocyclohexenes

Reactions of 2-aryl(heteryl)-1-acetyl(benzoyl)-1-nitroethenes with 2,3-dimethyl-1,3-butadiene led to the formation of products of [4+2]-cycloaddition, 1-acyl-6-aryl(heteryl)-3,4-dimethyl-1-nitro-3-cyclohexenes. Their structure was proved by IR and ¹H NMR spectroscopy.     

Hydrolysis of Cyclopropane Derivatives of Aspartic and Adipic Acids

Hydrolysis of substituted cyclopropane amino acids was performed. Free and partially substituted Z and E isomers of cyclopropane analogs of aspartic and adipic acids were obtained.     

Reactions of 1-bromo-1-nitro-3,3,3-trichloropropene with <Emphasis Type=Italic>O</Emphasis>- and <Emphasis Type=Italic>N</Emphasis>-nucleophiles

Reactions of 1-bromo-1-nitro-3,3,3-trichloropropene with alcohols, benzidine and o-, m-, and p-phenylenediamines was investigated and the reaction conditions were developed. The alkoxylation and amination products and an unusual nitrogen-containing bis-aziridine were obtained; their structures were characterized by the spectral (IR, ¹H, ¹³C NMR, HMQC, and HMBC) methods.     

Structure of 3,4-dinitro-3,4-dimethyl-1,1-diphenyl-1-silacyclopentane

Conclusions 3,4-Dinitro-3,4-dimethyl-1,1-diphenyl-1-silacyclopentane in the liquid phase has a half-chair conformation, and in the solid phase, its conformation is described by a form intermediate between the half-chair and the envelope conformation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2731–2736, December, 1985.     

Temperature effects in high-energy muon fluxes and the problem of reconstructing the atmospheric temperature profile

The temperature dependence of the high-energy muon flux is investigated using the experimental data from the Baksan Underground Scintillation Telescope. A method for reconstructing the atmosphere temperature profile is discussed.     

Effect of High-Temperature Treatment on Optical Properties of Silica Films Doped with Al2O3, P2O5 and Rare-Earth Elements

The paper reports effects of high-temperature treatment of silica layers doped with Al₂O₃, P₂O₅, Yb and Er ions, which are coated inside silica substrate tubes and transformed through viscous flow into the core of a preform, on properties of these cores. The gel layers are applied inside the silica substrate tubes from sols based on tetraethoxysilane and corresponding chlorides in isopropanol by controlled lowering the column of the sol. The layers are thermally treated at 500°C and subject to high-temperature treatment from 1000 to 1300°C. The tube with the layers is collapsed into a preform from which fibers are drawn at about 1950°C. The results of concentration measurements show that during the high-temperature treatment the content of silica in the layer increases at least five times in comparison with that of the sol composition. This effect depends on the sol composition and the number of the coated gel layers. Measurements show that in the prepared fibers there is some remaining unsaturated absorption of erbium ions at 1535 nm, which is related to quenching of the erbium ions.     

Effect of Doping Silica Gel Layers with TiOTi-Chains and Cu2+-Ephedrine on the Sensitivity of the Layers to Gases

In this paper the interaction of polysiloxane and TiOTi-doped polysiloxane gel layers containing Cu²⁺-ephedrine (CuEP) with carbon dioxide, nitrogen and water is investigated. This interaction is studied through changes of the output optical power from an optical fiber coated with the investigated gel layer. The layers are prepared with sols based on tetraethoxysilane and titanium isopropoxide, isopropanol, acetylacetone and Cu²⁺-ephedrine by the repeated dip-coating method. The applied gel layers are dried at 70°C.Spectral and temporal changes of the output optical power due to effect of the tested gases are measured. The measurements show big changes of the output optical power of fibers coated with CuEP-doped silica gel layers in a wavelength range from 400 to 700 nm, which is in relation with spectral effects of CuEP in alcoholic solutions. Relatively lower changes of the attenuation spectra without any attenuation band are found in the spectra of TiOTi-doped siloxane gel layers containing CuEP. The angular distributions of the output optical power of the coated fibers indicate high optical losses of the layers.     

Reactions of 1-nitrocyclohexene with <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-binucleophiles

A modification of 1-nitrocyclohexene synthesis is proposed; its reaction with phenylhydrazine and benzoic acid hydrazide is shown to afford monoadducts, and with hydrazine hydrate, bisaduct. With diphenylguanidine occurs heterocyclization to 1-phenyl-2-N-phenylamino-4,5,6,7-tetrahydrobenzimidazole, whose structure is confirmed by the X-ray diffraction data. The analysis performed for this compound of the electron density distribution function in the crystal made it possible to estimate the charge distribution, π-electrons delocalization nature, and the role of N-H…N, C-H…H-C and C-H…C interactions in the formation of the crystal packing.