Sulphur pentafluoride, reaction

Arsenic Pentafluoride, AsFs, may be prepared by the interaction of arsenic and fluorine in a platinum vessel,2 or by the action of bromine and antimony pentafluoride on arsenic trifluoride.3 The reagents should be dry, and if the reaction in the second case is carried out in a glass vessel, the apparatus should be in one piece and well dried. The bromine is added to the mixture of fluorides at - 20° C. and, after cooling in liquid air, the arsenic pentafluoride is obtained by heating on a water-bath at 55° C., the gas passing through a reflux condenser to a receiver surrounded by liquid air. The product contains bromine, which is removed by passing the gas over molten sulphur. 

HYDRoaEN fluoride rarely occurs free in nature but its presence has been detected in the effluvia from vents in volcanic districts for example, R. V. Matteucci found it in the gaseous products of the fumeroles of Vesuvius. Hydrogen fluoride is formed by the direct union of the elements and by the action of fluorine on water, ammonia, hydrocarbons, and many organic compounds. It is also formed by the action of steam on some of the metal fluorides—-lead fluoride, silver fluoride, etc.—and by the action of some fluorides on water—e.g. iodine pentafluoride. The fluorides and fluosilicates are decomposed by sulphuric acid, with the evolution of hydrogen fluoride—the reaction is incomplete with hydrochloric acid in place of sulphuric acid. G. Gore used chromic fluoride and sulphuric acid R. Luboldt decomposed cryolite with the same acid. 

The reaction between iVAr -bis(trimethylsilyl)sulphur di-imide and phosphorus pentafluoride gives a small amount of SaNgPFg, for which (77) is the suggested structure the n.m.r. spectrum shows two doublets,supporting... 

Ionic Reactions.—Reactions of either trans- or m-l-p-methoxyphenylpentafluoro-propene with antimony pentafluoride in sulphur dioxide yields the long-lived allyl cation (27), which yields ester (28) when quenched by methanol. No similar cation was observed with hexafluoropropene instead dimer (29) was isolated. Stable arenonium ions (see p. 377) are readily formed from fluorinated cyclohexa-1,4-dienes and -2,5-dienones. ... 

Gasteiger and Huisgen have discovered a particularly simple synthesis of (119). Reaction of cyclo-octatetraene with antimony pentafluoride in sulphur dioxide gives a 95% yield of (119). Photorearrangement of (120) or (121)... 

Addition of sulphur dioxide to cyclo-octatetraene in the presence of antimony pentafluoride gives the homotropylium ion (300), which on reaction with water produces (301). Addition of iodine azide and sodium azide to cyclo-octatetraene gives the diazide (302), which is in equilibrium with the bicyclo-... 

C,Fs-C N+ 2C1F->CjF5 CF, NC1 4.C,F,N N C,F, -1- Cl,). Pyrolysis (at 180°C) or photolysis of the CIF-adduct of theimineC,F,-N CF, ((CF,)-(C,F5)NC1, also obtainable via reaction of OF with (CF,XC,Fj)NH] yields the tetrasubstituted hydrazine (CF,XC,Fj)N N(C,FsXCF,). Reaction of chlorine monofluoride with potassium thiocyanate at — 30°C yields INW-dichlorotrifluoromethylamine, sulphur chloride pentafluoride, chlorine, potassium fluoride, and traces of sulphur hexafluoride and hexafluoroazo-methane. ... 

Trifluoromethylsulphur chloride tetrafluoride, CF3-SF4C1 (which possesses a tronj-octahedral configuration so that all four fluorines attached to sulphur are equivalent), has been prepared by reaction of trifluoromethylsulphur trifluoride with chlorine in the presence of caesium fluoride at room temperature this synthesis is analogous to that of sulphur chloride pentafluoride from sulphur tetrafluoride, chlorine, and caesium fluoride, a method claimed to be inferior to the addition of chlorine monofluoride to sulphur tetrafluoride in the presence of caesium fluoride specially activated by a fusion-solidification-fine-grinding technique. Bis(perfluoroalkyl)-sulphur difluorides result from the fluorination of bis(perfluoroalkyl) sulphides with chlorine monofluoride ... 

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