Perchloryl fluoride, FCIO

Perchlorylation. The stabiUty of perchloryl fluoride [7616-94-6] FCIO, makes possible perchlorylation of aromatics, a reaction closely related to the Friedel-Crafts acylation (159) ... 

The perchloryl fluoride [7616-94-6] FCIO, the acyl fluoride of perchloric acid, is a stable compound. Normally a gas having a melting poiat of —147.7° C and a boiling poiat of —46.7°C, it can be prepared by electrolysis of a saturated solution of sodium perchlorate ia anhydrous hydrofluoric acid. Some of its uses are as an effective fluorinating agent, as an oxidant ia rocket fuels, and as a gaseous dielectric for transformers (69). 

These compounds range from the thermally unstable FCIO to the rather chemically inert perchloryl fluoride FCIO3. The structure and properties of this family of compounds resemble those of the halogen fluorides. Therefore, they have to be handled with the same care as elemental fluorine and its chemically reactive fluorides. The halogen oxide fluorides can be prepared by fluorination of halogen oxides with elemental fluorine or with halogen fluoride. 

Oxofluorination. This is the name given hy Neeman to a new electrophilic nmhidcnt reaction of perchloryl fluoride with olefins of the type of indene (1). A solution of indene in aqueous dioxane is kept saturated with FCIO at room... 

Five chlorine oxyfluorides have been definitely characterized (Table VIII). Their stabilities range from FCIO, which decomposes with a half-Ufe of about 25 at room temperature, to FCIO3 (perchloryl fluoride), which is thermally stable to about 400°C. 

---