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The ionic composition of the HF–SbF5 superacid system has been investigated by 1H and 19F high field NMR. The anionic distribution over the whole composition range could be directly calculated from the 19F NMR spectra. The cationic distribution was then estimated on the basis of charge balance. When the concentration of SbF5 in HF was higher than 20 mol%, increasing amounts of nonassociated SbF5 appeared. This change in composition can be linked to the change in reactivity of the superacid system in the activation process of small alkanes.

Electrophilic aromatic bromination of phenol ethers in superacid medium can be achieved with sodium or potassium bromide. The yield and selectivity are lower than with bromine, the oxidation of the halide to the electrophilic halogen cation is obtained by concomitant reduction of antimony pentafluoride. Selectivity is observed only in methylanisole.

The ionic composition of the HF–SbF5 superacid system has been investigated by 1H and 19F high field NMR. The anionic distribution over the whole composition range could be directly calculated from the 19F NMR spectra. The cationic distribution was then estimated on the basis of charge balance. When the concentration of SbF5 in HF was higher than 20 mol%, increasing amounts of nonassociated SbF5 appeared. This change in composition can be linked to the change in reactivity of the superacid system in the activation process of small alkanes.

Electrophilic aromatic bromination of phenol ethers in superacid medium can be achieved with sodium or potassium bromide. The yield and selectivity are lower than with bromine, the oxidation of the halide to the electrophilic halogen cation is obtained by concomitant reduction of antimony pentafluoride. Selectivity is observed only in methylanisole.

The halogen-promoted regioselective carbonylation of propane in HF–SbF5 shows a strong dependence of the rates on the partial pressure of CO indicating that carbon monoxide is associated with the halogen in the activation step.

Acid-catalyzed hydrocarbon conversion processes such as isomerization, alkylation, and cracking are industrial transformations of high economic importance. The common key step in these reactions is the formation of the reactive trivalent carbocations. In this work, they report experimental proof of the direct oxidation of isobutane by antimony pentafluoride to the tert-butyl cation. The presence of a proton trap shows that the proton is not essential for this ionization process.

Acid-catalyzed hydrocarbon conversion processes such as isomerization, alkylation, and cracking are industrial transformations of high economic importance. The common key step in these reactions is the formation of the reactive trivalent carbocations. In this work, they report experimental proof of the direct oxidation of isobutane by antimony pentafluoride to the tert-butyl cation. The presence of a proton trap shows that the proton is not essential for this ionization process.

Carbonylation of propane in HF–SbF5(5 : 1 molar ratio) superacid in the presence of carbon tetrachloride (or chloroform) at –30 °C yields exclusively the isobutyryl ion (isopropyloxocarbenium ion), analysis of the gaseous fluorocarbons generated as side products showing both hydride abstraction by CCl3+(or CHCl2+) and Cl/F exchange on the tri- and di-chloromethane formed; in the absence of CCl4(or CHCl3) no reaction takes place under the same experimental conditions.

Protolytic ionization of methylcyclopentane in HF SbF 5 , followed by carbonylation at atmospheric pressure yields either methyl cyclopentane- or cyclohexaneoxocarbenium ions depending on the reaction temperature. An example of kinetic versus thermodynamic control.