Oxygen difluoride synthesis

Commercial applications of oxygen difluoride are bmited. It is used in organic synthesis to prepare fluoropropylenes and acylfluorides. It is used as an oxidizing and fluorinating agent in many preparative reactions and as a monomer in diolefin copolymerization. 

Oxygen difluoride (OF2) is an attractive oxidizer for many fuels (II, 16), especially hydrocarbons, because it provides the optimum O/F ratio for hydrocarbon oxidation. Since it is denser than the equimolar 02-F2 mixture (Flox), it should be easier to handle and should perform better. However, OF2 has been expensive to make because the usual preparation from F2 plus base (18) converts half the F2 to F . Consequently, the less attractive but lower cost Flox mixtures have received more attention. A better synthesis for OF2 would remove this obstacle and justify a more thorough investigation of its performance. 

PFCAs can also be synthesized by electrochemical fluorination of the corresponding alkanoic acid however, the yield of this reaction is only 10-20%. Slightly higher yields can be obtained by fluorination of the corresponding anhydrides. For example, acetic acid and acetic acid anhydride form perfluoroacetyl fluoride in a 17% and 32% yield, respectively. A major disadvantage of this approach is the formation of water that may form explosive oxygen difluoride. Simple alkanoic acids were, therefore, never useful starting materials for the industrial synthesis of PFCA fluorides. 

Nitriles are resistant to reaction with sulfur tetrafluoride under the conditions generally used for fluorination of oxygen functions. Acetonitrile, which is used as the solvent in the laboratory synthesis of sulfur tetrafluoride (see Section 8.1.2.), is particularly resistant and no reaction occurs up to 260"C, at which temperature extensive decomposition takes place and 1,1,2-tri-fluoroethyliminosulfur difluoride is formed in low yield,202... 

Carbonyl difluoride is a particularly versatile fluorinating agent, and an important material for the synthesis of organofluorine compounds [1079], Its reactions with perfluoroalkenes gives perfluoroacyl fluorides in the presence of a fluoride ion source, and its facile reaction with amines or alcohols results in the formation of carbamoyl fluorides or fluoroformates, respectively. The fluorination of carbonyl compounds, such as aldehydes and ketones, with COF can give gem-difluorides by replacement of the carbonyl oxygen atom with two atoms of fluorine e.g.-. 

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