Effect of Chromium Oxide Additions on the Stability of Glass Ceramic Sealants for Solid Oxide Fuel Cells

Russian Journal of Applied Chemistry - The development of electrochemical generators based on solid oxide fuel cells requires the development of sealant materials that would ensure gastight...     

Synthesis and curing of epoxy-anhydride polymers modified with an oxirane of the tetrahydroquinoline series

Epoxy-anhydride polymers were prepared from diphenylolpropane diglycidyl ether and isomethyltetrahydrophthalic anhydride in the presence of a chemical modifier, oxirane of the tetrahydroquinoline series. The kinetics of the reaction of the modifier with the anhydride and the curing kinetics of the polymeric compound containing the modifier were studied. The thermal properties and water absorption of the polymers after their curing and structure formation were determined.     

The interaction of coordinationally unsaturated 2,9-dimethylphenanthroline cobalt complex with adenine nucleotides

The study of complex formation between adenosine triphosphate (ATP) or adenosine diphosphate (ADP) and coordinationally unsaturated cobalt complex with 2, 9-dimethyl-o-phenanthroline (L) showed the possibility of formation of relatively stable mixed ligand complex CoL·ATP (log=4.45). The latter may be formed under the oxidative phosphorylation conditions in mitochondria. The presence of ATP in the complex provides the specific inhibition of the ATPase active center.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 744–748, April, 1994.     

Synthesis of Polysubstituted 1,4-Diazacycloheptan-5-ones. 1. Synthesis and Conformational Investigation of Polysubstituted 4-Piperidones

A series of tri- and tetrasubstituted 4-piperidones and their bicyclic analogs has been synthesized. It was established by ¹H NMR spectroscopy that all the piperidones obtained have the chair conformation in solution with equatorially disposed substituents.     

Copolymers of betulin esters and silver nanocomposites based on them

New biologically active silver nanocomposites based on the copolymer of lup-20(29)-ene-3,28-diol 28-O-vinylbenzoate with N-vinylpyrrolidone were prepared by the borohydride method. The formation of spherical nanoparticles with a mean diameter of 67 nm was confirmed by scanning electron microscopy. The synthesized copolymers and silver nanocomposites exhibit cytotoxic activity and show promise for the development of new materials for medical purposes.     

Structures of Bismuth(III) Complexonates in Aqueous Solutions Studied by 1H NMR Method

Aqueous solutions of bismuth(III) nitrilotriacetates BiNta · 2H₂O and M₃Bi(Nta)₂ ·nH₂O (M = Na, K, Rb, Cs, NH₄, CN₃H₆, n = 0–4) and the K[Bi(Edta)(Tu)₂] complex (Edta^4– is the anion of ethylenediaminetetraacetic acid, Tu is thiocarbamide) are studied by the ¹H NMR method at room temperature in the pH interval from 2 to 11. The formation of two types of bismuth nitrilotriacetate complexes in solutions is established. They are characterized by the presence (type 1) or absence (type 2) of the Bi–N bond. Their ratio, depending on the composition and pH of the solution, is determined. The K[Bi(Edta)(Tu)₂] compound in solutions occurs as one form. The pH values at which the substance begins to decompose are determined for each compound.     

Changes in the magnetic parameters of amorphous alloys as an indicator of structural transformations

Metallic glasses exhibit unusual physical properties, compared to their crystalline analogues of the same composition. Thermal annealing of amorphous alloys leads to the multistep transformation of their structures, considerably altering their magnetic state. The high sensitivity of magnetic characteristics to the early stages of crystallization allows us to consider the temperature dependence of saturation magnetization as an indicator of such transformations.     

Preparation of bis(1-R-o-carboranyl)mercury by direct mercuration of 1-R-o-carboranes with mercury salts in alkaline solution

Conclusions The 1-R-o-carboranes undergo direct mercuration by HgBr₂ in aqueous alkali solution to give the bis(1-R-o-carboranyl)mercury.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1184–1185, May, 1984.