The electrosurface characteristics of dispersions of silicon and titanium aeroxides in solutions containing indifferent and specifically sorbed ions

The electrokinetic potentials of silicon and titanium aeroxides and the adsorption of potential-determining ions on them are measured as functions of pH in 10^?3-1 M NaCl solutions. The positions of the points of zero charge and the isoelectric points are determined. The adsorption of a cationic dye, oxazine 1, from aqueous solutions free of background electrolytes and in the presence of 10^?2 M NaCl is measured for both the oxides. The effect of the adsorption of the specifically sorbed cation on the electrokinetic behavior of the tested aeroxides is analyzed.     

4-(<Emphasis Type="Italic">N,N</Emphasis>-Dialkylthiocarbamoylthio)-5-nitropyrimidines as new potential nitric oxide donors

On heating at pH 6.86, 4-(N,N-dialkylthiocarbamoylthio)-5-nitropyrimidines are transformed into dithiolopyrimidines, which are either oxidized to bis(4-dialkylthiocarbamoylpyrimidin-5-yl) disulfides or converted into 4,6-diamino-5-nitropyrimidine derivatives with carbon disulfide elimination. The direction of the reaction is determined by the nature of a substituent in position 2 of pyrimidine and the bulk of the thiocarbamate substituent. Mechanistic schemes for these processes were proposed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2777–2783, December, 2005.     

Synthesis of Carboxylated Monodisperse Latexes and Their Self-Organization in Thin Films

The capability of carboxylated latexes of poly(methyl methacrylate) and copolymers of styrene with glycidyl methacrylate or methacrylic acid for self-organization in thin films was studied in relation to the compositions of the dispersion medium and polymer and to the latex particle size.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 1, 2005, pp. 161–167.Original Russian Text Copyright © 2005 by Men’shikova, Shabsel’s, Evseeva, Shevchenko, Bilibin.     

Synthesis of macrocycles incorporating azo‐bis(azofurazan) framework

A series of macrocycles containing four furazan rings bonded by three azo bonds 2, 5 and 7 have been synthesized from the common precursor, 3‐amino‐3′‐nitro(azofurazan) 3 . The macrocycles closure is a result of N?N bond formation at oxidative cyclization of corresponding bis(3‐aminofurazan‐4‐yl) precursors. X‐Ray crystal structures of macrocycles 2, 2 ?AcOH, 11 and 13 are reported.     

On-Line Sorption–Chromatographic Determination of Phenols with Amperometric Detection

Conditions of the preconcentration of phenol on a microcolumn filled with MN-200 hypercrosslinked polystyrene were determined using the linear sorption dynamics model. Conditions of the on-line determination of phenol and its chloro derivatives by reversed-phase high-performance liquid chromatography with amperometric detection were optimized. The detection limit of phenol and chlorophenols for preconcentration from 30 mL of a sample was 3 and 15 ng/L, respectively. The proposed procedure was used for the determination of phenols in tap and river water.     

Foliosidine acetonide

Summary Foliosidine acetonide has been isolated from the mixture of alkaloids fromH. foliosum.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 724–727, November–December, 1970.     

2-isoxazolines from arylcyclopropanes: I. Monoarylcyclopropanes in a reaction with nitrosyl chloride activated by sulfur(IV) oxide

A reaction of monoarylcyclopropanes with nitrosyl chloride activated by sulfur (IV) oxide gave in good yields 5-arylisoxazolines. The reaction is of electrophilic character. A scheme of the reaction was suggested.     

Catalytic methods for obtaining thiophene and alkylthiophenes from petroleum refining products and sulfur-containing organic compounds

This review is devoted to catalytic methods for obtaining thiophene and alkylthiophenes from C₂-C₆ hydrocarbons and from various organosulfur compounds — aliphatic sulfides, mercaptans, alkylthiophenes, thiophane, and sulfones. Multicomponent chromium-containing catalysts have considerable activity in the majority of the reactions. The catalytic method for obtaining thiophene and alkylthiophenes by the reaction of C₂-C₆ hydrocarbons with hydrogen sulfide may be the most promising one.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1299–1312, October, 1971.     

Preparative fractionation of cerebral gangliosides with the aid of ion-exchange chromatography on Spheron CH 300

A new preparative method is proposed for the separation of natural mixtures of gangliosides into fractions of mono-, di-, and trisialogangliosides which is based on ion-exchange chromatography on a weak anion-exchange resin — Spheron CH 300. The latter ensures a considerably faster separation than the ion-exchange resins usually employed.Scientific-Research Laboratory of Biologically Active Substances of Hydrobionts, USSR Ministry of Health, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 28–30, January–February, 1990.