Diffusion Modification of Polymethyl Methacrylate with Oligoglycol Acrylates

The structural transformations of oligoglycol acrylates in the surface layers of polymethyl methacrylate were studied.     

Kabachnik–Fields Reaction in the Synthesis of New Acetal-Containing Aminophosphine Oxides

Russian Journal of General Chemistry - The Kabachnik–Fields reaction in a ternary system of 4,4-diethoxybutylamine–dialkyl(tolyl)-phosphine...     

1,3,2(1,4,2)-Dioxaphosphepins annelated with naphthalene fragment: Synthesis and steric structure

Reaction of hexafluoroacetone and chloral with 2-R-naphtho-1,3,2-dioxaphosphorin-4-ones yields 2-R-2,5-dioxo-4,4-bis(trifluoromethyl)naphthol-1,3,2-and 2-R-2,5-dioxo-3-trichloromethylnaphtho-1,4,2λ⁵-dioxaphosphepins. Hydrolysis of the fluorophosphepins gives naphthyl-substituted fluorinated hydroxy ketones. The steric structure of the dioxaphosphepins and some fluorinated ketones was confirmed by single crystal X-ray diffraction. A competition between the π-π and halogen-halogen interactions and hydrogen bonds of classic type in the formation of crystal packing and supramolecular structure was revealed.     

Oxidation of quinopimaric acid derivatives by dimethyldioxirane

Successful application of dimethyldioxirane for selective oxidation of an oxygen-containing tertiary C atom to form a hemiacetal, the preparation of which is inaccessible by other methods, was demonstrated using dihydroquinopimaric acid derivatives as examples.     

Synthesis of nontrivial quinopimaric acid derivatives by oxidation with dimethyldioxirane

Oxidation of dihydroquinopimaric acid methyl ester and its derivatives with dimethyldioxirane results in the formation of a nontrivial derivative and hemiacetals in high yields with excellent regioselectivity, as is demonstrated for an unsaturated diol. The structures of the products were confirmed by X-ray crystallographic analysis. Dihydroquinopimaric acid and its nontrivial derivative are found to be moderately active against influenza virus type A and the papilloma virus.     

Phase formation in the BaCO<Subscript>3</Subscript>–PbO–Fe<Subscript>2</Subscript>O<Subscript>3</Subscript>–Nb<Subscript>2</Subscript>O<Subscript>5</Subscript> system

Features of the formation of lead-ferroniobate compounds in the xBaCO₃–(1 – x)PbO–Fe₂O₃–Nb₂O₅ system by solid-phase synthesis are investigated. For perovskite-type lead-ferroniobate solid solution, a single-phase concentration region is revealed at 1233 K. The crystalline structures of the synthesized compounds are refined using Rietveld analysis and the Pm3?m and R3m space groups. Ceramic samples of lead ferroniobate are studied by scanning electron microscopy.