ISOLATION AND CHARACTERIZATION OF METHYL HYPOFLUORITE (CH3OF)

Methyl hypofluorite (CH3OF) has been prepared by the reaction of elemental fluorine with methanol in acetonitrile or propionitrile at low temperature. It was removed from the reaction mixture in a stream of nitrogen and purified by fractional distillation. The compound is moderately long-lived, although the liquid has exploded upon rapid warming. The liquid compound has a freezing point of about -142-degrees-C, and vapor pressure measurements indicate a normal boiling point of -32.6 +/- 0.9-degree-C and an enthalpy of vaporization of 23.37 +/- 0.26 kJ/mol. The infrared spectrum of the vapor is consistent with the molecule being isostructural with CH3OH and CF3OF. The compound has also been characterized by mass spectrometry and by H-1, F-19, and C-13 NMR spectrometries. This novel reagent adds across various double bonds to form the corresponding fluoro methoxy adducts, which are not easily accessible by other methods.