Arylation of Pyridine with 9,10-Dioxoanthracenyl-1(2)-diazonium Hydrosulfates

Russian Journal of General Chemistry - 9,10-Dioxoanthracenyl-1(2)-diazonium hydrosulfates reacted with pyridine under both the modified Gomberg–Bachmann reaction conditions and in the...     

Effect of Indium Oxide Modification on the Phase Composition,the Structure of a Hydroxyl Cover,and the Electron-Acceptor Properties of Zirconium Dioxide

The effect of modification with indium oxide on the crystal structure, hydroxyl cover, and electron-acceptor properties of zirconium dioxide was studied. It was found that complex binary systems with a highly thermally stable tetragonal ZrO₂ phase can be prepared by the modification. The concentration of In³⁺ in the lattice of ZrO₂ depends only slightly on the total concentration of In₂O₃ in the system. The major portion of the indium oxide added is localized as an individual X-ray amorphous phase in intercrystallite voids. The In₂O₃ phase formed in these systems does not cover the surface of ZrO₂ but is mainly localized in the intercrystallite space. The presence of the modifier component affects the predominant crystallographic direction and the defect structure of the surface formed. The modification was found to affect the structure of a hydroxyl cover and the electron-acceptor properties of zirconium dioxide.     

Thermal irradiation of deactivated heterogeneous catalysts

Radiation heating decreases 10–100 — fold the regeneration time of deactivated catalysts, accelerates the removal of carbon and sulfur, affects on phase composition, pore structure and mechanical properties of catalysts and sorbents.     

Some new polymeric semiconductors

This paper deals with some new methods for synthesis of the polymeric semiconductors by conjugated reactions and also with electrophysical properties of the polymers. Elimination of hydrogen halides from α,β-dihalo derivatives by bases (calcium oxide or tertiary amines) yields polymers with conjugated bonds. The reaction proceeds at 200–300°C. under atmospheric or elevated pressures, acetylenes being the intermediates. α,β-Dihalo compounds with calcium carbide above 150°C. produce polyacetylenic copolymers by elimination of two moles of hydrogen halide, also by generating acetylene from calcium carbide. The identical reaction (elimination of water) was observed between carbonyl compounds and calcium carbide. Elimination of water from monoand bifunctional phenols in the presence of zinc chloride under pressure above 200°C. yields polyphenylenes and polyhydroxyphenylenes, dehydrobenzene (benzyne) and hydroxybenzyne being intermediates. The polyhydroxyphenylenes prepared have a degree of polymerization from 4–5 to several thousand and are of interest as intermediates for thermostable resins, inhibitors etc. Linear polycyanamide and polycyanic acid were first prepared by polycondensation of urea with ammonium bicarbonate in the presence of zinc chloride. Analogous polymers were obtained from the ring-opening polymerization of melamine and cyanuric acid. The polymers show good semiconductor and ion-exchange properties. Polycondensation of ketones with ammonium bicarbonate also gave conjugated polymers. Thus, organometallic polymers were prepared from acetyl- and diacetyl ferrocene. We have also studied electrophysical, magnetic, and catalytic properties of the conjugated polymers prepared by the new methods. The electrical conductivity of the best specimens ranged from 10^?3 to 10^?6 ohm^?1 cm.^?1; the number of electrons unpaired was 10¹⁸–10¹⁹ spins/g.     

Calculational method for isoparametric compositions and the width of the forbidden band of five-component solid solutions based on AIII BV compounds

A method is presented for the thermodynamic calculation of the isoparametric composition and of the width of the forbidden band of five-component solid solutions of A^III B^V compounds. Calculation has been performed of compositions and of the width of the forbidden band of five-component solid solutions whose lattice is commensurate with binary substrates A^III B^V. The necessity of taking into account the effect of ordering on the width of the forbidden band of a solid solution is shown.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 41–47, July, 1989.     

Synthesis and properties of symm-triazines. 3. Reactions of 2-alkyl-4,6-bistrichloromethyl-symm-triazines containing higher alkyl groups with ammonia and aliphatic amines

The reaction of 2-alkyl-4,6-bistrichloromethyl-symm-triazines containing higher alkyl groups with ammonia or aliphatic amines results, depending on the reaction conditions, in the replacement of one or both trichloromethyl groups. On heating these symm-triazines with aqueous ammonia or dimethylamine, 2-oxo-4-amino-6-alkyl-1(3)H-symm-triazines are obtained.For communication 2, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1557–1563, November, 1985.     

Alteration of the thermodynamic characteristics of corneal collagen denaturation as a result of nonenzymatic glycation

The thermal stability of the scleral and corneal tissues after in vitro treatment with ribose, threose, and glyceraldehyde was investigated. The thermal transition temperature and the enthalpy of collagen fiber crosslinking were determined by differential scanning calorimetry (DSC). The resistance of the tissues toward trypsin was also determined after heating tissue samples in the DSC furnace. It was shown that the denaturation temperature of scleral and corneal samples treated by crosslinking agents increased, but the enthalpy of denaturation decreased. It is suggested that crosslinking in the collagen matrix of the cornea and sclera prevents complete collagen denaturation if the temperature does not rise up to 110 °C.     

Formation of Co-Ru/MgO/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalysts for the Fischer-Tropsch synthesis: A magnetic method for the estimation of cobalt particle size

The physicochemical properties of Co-supported catalysts were studied, and the particle size of Co in Co/MgO/Al₂O₃ and Co-0.2% Ru/MgO/Al₂O₃ catalysts for the Fischer-Tropsch synthesis (FTS) was estimated using a magnetic method. It was found that a considerable fraction of superparamagnetic Co particles, which increase selectivity for C₅₊ hydrocarbons and decrease the yield of methane in the FTS, was present in a ruthenium-containing catalyst along with single-domain ferromagnetic particles. In this case, the catalyst activity increased by a factor of 10.     

Hydrodechlorination of Tetrachloromethane in the Vapor Phase in the Presence of Pd–Fe/Sibunit Catalysts

The hydrodechlorination of CCl₄ in the presence of Pd–Fe/Sibunit catalysts of different composition was studied. An optimum concentration of the metals (2.5% at the ratio Pd/Fe = 1 : 4) was determined, which corresponds to the highest stability of catalysts and selectivity of C₂–C₄ olefin and paraffin formation. With the use of TPR and magnetic measurements, it was found that the metals occurred in an oxidized state in the course of the reaction; it is likely that this resulted in the formation of C₂–C₄ hydrocarbons.