α‐Fluoroalcohols: Synthesis and Characterization of Perfluorinated Methanol, Ethanol and n‐Propanol, and their Oxonium Salts

The thermally unstable, primary perfluoroalcohols, CF 3 OH, C 2 F 5 OH, and n C 3 F 7 OH, were conveniently prepared from the corresponding carbonyl compounds in anhydrous HF solution. Experimental values for the reaction enthalpies and entropies were derived from the temperature dependence of the R f COF+HF⇄R f CF 2 OH ( R f =F, CF 3 , CF 3 CF 2 ) equilibria by NMR spectroscopy. Electronic structure calculations of the gas‐phase and solution reaction energies, gas‐phase acidities and heats of formation were carried out at the G3MP2 level, showing that these compounds are strong acids. Protonation of these alcohols in HF/SbF 5 produced the perfluoroalkyl oxonium salts R f CF 2 OH 2 + SbF 6 − .