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

The thermally unstable, primary perfluoroalcohols, CF OH, C F OH, and nC F 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 COF+HF⇄R CF OH (R =F, CF , CF CF ) 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 produced the perfluoroalkyl oxonium salts R CF OH SbF .