Improvement of procedures for preparing Tetrafluoroethane-β-sultone and fluorocarbonyldifluoromethanesulfonyl fluoride

Synthesis of tetrafluoroethane-β-sultone by the reaction of tetrafluoroethylene with sulfuric anhydride and of fluorocarbonyldifluoromethanesulfonyl fluoride by catalytic reaction of tetrafluoroethylene with sulfuric anhydride using BAU-2, SKT-6, or AG-3 activated carbon as catalyst was studied. The possibility of replacing sulfuric anhydride prepared by distillation from oleum by sulfuric anhydride prepared by sulfur dioxide oxidation was demonstrated.     

A 19F NMR study of products of hexafluorobutadiene sulfotrioxidation

The products of hexafluorobutadiene sulfotrioxidation were identified by ¹⁹F NMR. The major products are hexafluoro-1-butene-3,4-β-sultone, hexafluoro-2-butene-1,4-sultone, hexafluoro-1-butene-3,4-pyrosultone, and hexafluoro-2-buten-1,4-diyl sulfate.     

Catalytic synthesis of certain perfluorinated ketones and study of their structure by 19F NMR spectroscopy

An efficient catalyst of a perfluorinated ketone synthesis of a high selectivity in the absence of solvent was proposed. Products of reaction of perfluorinated fluorides of various structures with tetrafluoroethylene and hexafluoropropylene in the presence of efficient catalysts without solvent were examined. The structure of the resulting products and their isomeric composition were identified by ¹⁹F NMR spectrscopy.     

Development of technology of perfluoroethyl isopropyl ketone production

Synthesis of perfluoroethyl isopropyl ketone by an interaction of hexafluoropropene with perfluoropropionic acid fluoride or hexafluoropropene oxide was examined. Interchangeability of perfluoropropionic acid fluoride and hexafluoropropene oxide was demonstrated. The features of perfluoroethyl isopropyl ketone synthesis were studied in polar aprotic solvents on catalysts: alkali metal fluoride. A method for obtaining perfluoroethyl isopropyl ketone by direct catalytic reaction in a tubular reactor without use of solvents was suggested and investigated. The mechanism of interaction was considered. The main impurities resulting in obtaining perfluoroethyl isopropyl ketone were determined. The methods of cleaning perfluoroethyl isopropyl ketone were worked out.     

Some exact solutions of the equations of the mechanics of nonhomogeneous media

We consider problems of the torsion of nonhomogeneous prismatic rods and the oscillation of plats of variable thickness operating in shear. We obtain an inequality characterizing the dependence of the maximum tangential stress on the shear modulus. An estimate from below is obtained for the torsional moment. An optimization problem for plates of variable thickness for a specified class of thicknesses is reduced to a problem on characteristic values for the Helmholtz equation.Translated from Matematicheskie Metody i Fiziko-Mekhanicheskie Polya, No. 25, pp. 87–90, 1987.     

Perfluoroethanesulfonyl fluoride: Preparation from sultone

A procedure was developed for preparing perfluoroethanesulfonyl fluoride by synthesis of hexafluoropropane-2-β-sultone from sulfuric anhydride and perfluoropropene, followed by hydrolysis of the sultone to α-tetrafluoroethanesulfonyl fluoride and fluorination of the latter with elemental fluorine.     

Fluorination of Organic Compounds with Cobalt Trifluoride and Elemental Fluorine in the Presence of Cobalt Trifluoride

Fluorination of organic compounds with cobalt trifluoride and elemental fluorine in the presence of cobalt trifluoride was studied. Fluorination with elemental fluorine proceeds under external-kinetic control at a constant rate. Examples of fluorination with elemental fluorine of certain fluorinated olefins and polyfluorinated paraffins in the presence of CoF₃ are presented.