The anodic behavior of saturated hydrocarbons in fluorosulfuric acid

The oligocondensations of methane, ethane and propane have been studied by allowing an excess of these hydrocarbons to react on carbenium ions, derived from these alkanes (and obtained by their gentle oxidation at an anode) dissolved in HSO 3 F + HF mixture (1:1) which is a good non-nucleophilic solvent. Since these three compounds are not chemically oxidized by HSO 3 F into the corresponding carbenium ions, unlike all the other saturated hydrocarbons, an activation method has been developed. Thus the electrooxidation of these gases was conducted successfully in the mixture HSO 3 F + HF (1:1) with anodes made of platinum or vitreous carbon “V10”. Ethane was formed from methane and propane, isobutane and isopentane were formed from ethane. The oligocondensation of methane comes to a stop, to give predominantly ethane due to the low electrooxidation rate of this last compound compared with that of methane. In the case of propane, isobutane, isopentane and a mixture of branched-chain hexanes were obtained. A high pressure electrolysis cell has been developed.