Hydrogen fluoride-antimony pentafluoride

C. The Fluorosvlphonic Acid-Antimony Pentafluoride and Hydrogen Fluoride-Antimony Pentafluoride Solvent Systems Attempts to generate simple alkyl-, arylalkyl-, and cycloalkyl-carbonium ions in sulphuric acid or oleum solution generally result in... 

Hydrogen fluoride-Antimony pentafluoride [1,456, before Hydrogen peroxide]. 

Carbonylation of organoboranes Carbon monoxide. N,N -Carbonyl-diimidazole. 2,3-Dimethyl-2-butylborane. Hydrogen fluoride—Antimony pentafluoride. Lithium trimethoxyaluminum hydride. Palladium (II) chloride. 

An interesting de-aromatization of phenols in superacidic medium has been reported. The reaction of oestrone (81) with a hydrogen fluoride-antimony pentafluoride mixture afforded the diene-dione (87) in high yield. Dienones such... 

Hydrogen Fluoride-Antimony Pentafluoride (Fluoroantimonic Acid)... 

Hydrogen fluoride/antimony pentafluoride Migration of carbon-carbon double bonds s. 27, 159... 

Hydrogen fluoride/antimony pentafluoride Reaction in superacidic medium Isocyclic ring closure with dearomatization of phenolethers... 

Strfvents for Radical/C don Salts. All of the perfluoro aromatic cation salts are readily soluble in anhydrous hydrogen fluoride, antimony, and iodine pentafluorides and in dry sulfur dioxide. The marked dependency of solubility in HF on temperature provided for the formation of crystals useful for single-crystal X-ray diffraction studies in the case of C FgAsP. The freshly prepared salt was dissolved in anhydrous HF at room temperature and the solution cooled slowly 10 195 K, when amber-colored... 

Perchloric acid (HCIO4 Ho —13.0), fluorosulfuric acid (HSO3F Ho — 15.1), and trifluoromethanesulfonic acid (CF3SO3H Ho —14.1) are considered to be superacids, as is truly anhydrous hydrogen fluoride. Complexing with Lewis acidic metal fluorides of higher valence, such as antimony, tantalum, or niobium pentafluoride, greatly enhances the acidity of all these acids. 

Properties. Antimony pentafluoride [7783-70-2], SbF, is a colorless, hygroscopic, very viscous liquid that fumes ia air. Its viscosity at 20°C is 460 mPa-s(=cP) which is very close to the value for glycerol. The polymerization of high purity SbF at ambient temperature can be prevented by addition of 1% anhydrous hydrogen fluoride, which can be removed by distillation prior to the use of SbF. The pure product melts at 7°C (11), boils at 142.7°C,... 

For anhydrous hydrogen fluoride, the Hammett acidity function Hq approaches —11. The high negative value of Hq shows anhydrous hydrogen fluoride to be in the class of superacids. Addition of antimony pentafluoride to make a 3 Af solution in anhydrous hydrogen fluoride raises the Hammett function to —15.2, nearly the strongest of all acids (34). 

Fluorination and iodination reactions are used relatively littie in dye synthesis. Fluorinated species include the trifluoromethyl group, which can be obtained from the trichi oromethyl group by the action of hydrogen fluoride or antimony pentafluoride, and various fluorotria2iQyl and pyrimidyl reactive systems for reactive dyes, eg, Cibacron F dyes. 

Grown Ethers. Ethylene oxide forms cycHc oligomers (crown ethers) in the presence of fluorinated Lewis acids such as boron tritiuoride, phosphoms pentafluoride, or antimony pentafluoride. Hydrogen fluoride is the preferred catalyst (47). The presence of BF , PF , or SbF salts of alkah, alkaline earth, or transition metals directs the oligomerization to the cycHc tetramer, 1,4,7,10-tetraoxacyclododecane [294-93-9] (12-crown-4), pentamer, 1,4,7,10,13-pentaoxacyclopentadecane [33100-27-6] (15-crown-6), andhexamer, 1,4,7,10,13,16-hexaoxacyclooctadecane [17455-13-9]... 

Gillespie, R. J. et al., J. Chem. Soc., Chem. Comm., 1977, 595-597 Although stable at below -40°C in absence of moisture, it will explode if warmed rapidly (>20°C/h). Explosive decomposition of the solid difluoride oxide at -196°C occurs on contact with mercury, or antimony pentafluoride or arsenic pentafluoride [1], The fluoride explodes at about 0°C, and also in contact with arsenic pentafluoride in absence of hydrogen fluoride at -78°C [2],... 

Antimony pentafluoride is prepared by the reaction of antimony pentachlo-ride with anhydrous hydrogen fluoride ... 

Recently it has been reported (5,66) that ethylene oxide leads to a mixture of cyclic oligomers of D. P. 3,4, 5,6,7,8 and 9 (7 4 6 6 2 1), unaccompanied by open-chain oligomers and polymers, when treated with fluorine-containing catalysts such as antimony pentafluoride or a 1 1 mixture of borontrifluoride and hydrogen fluoride. 

These solutions are thus less acidic than those of antimony pentafluoride because the H2F+ concentration is lower. PF6 appears to behave as a non-electrolyte and it must be concluded that it is too weak a fluoride ion acceptor to enhance the acid properties of hydrogen fluoride (Dean et al., 1970). The strong proton acid HS03F exhibits no appreciable acid properties in HF (Gillespie and Humphreys, 1970). 

All manipulations were carried out in Kel-F, Teflon FEP, or fused silica reaction vessels attached to a stainless steel or Monel fluorine-type vacuum system and/or in a Vacuum Atmospheres inert atmosphere Dri lab. Hexafluorobenzme, oclafluorotoluene, octafluoronaphthalene (PCR Inc., Gainesville, FL), sulfur dioxide, anhydrous hydrogen fluoride (Matheson, E. Rutherford, NJ), cesium fluoride (ROC/RIC, Sun Valley, CA), trifluoroacetic acid (Aldrich, Milwaukee, Wl), and tungsten hexafluoride, arsenic pentafluoride, and antimony pentafluoride (Ozark-Mahoning, Inc., Tulsa, OK) were used as received after their purity was checked by infrared spectroscopy. Dioxygenyl salts and rhenium and... 

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