Halogens hypofluorous acid

Hypofluorous acid is the most recent of the halogen oxoacids to be prepared. Traces were obtained in 1968 by photolysis of a mixture of F2 and H2O in a matrix of solid N2 at 14-20 K but weighable amounts of the compound were first obtained by M. H. Studier and E. H. Appelman in 1971 by the fluorination of ice ... 

Fluorination of ice yields milligram amounts of hypofluorous acid, HOF, which is unstable at RT . Solutions of the other hypohalous acids and hypohalites are formed via disproportionative hydrolysis of the halogens ... 

The only oxoacid of fluorine that has been prepared is unstable hypofluorous acid, HOF. Aqueous hypohalous acids (except HOF) can be prepared by reaction of free halogens (CI2, Br2, I2) with cold water. The smaller the halogen, the farther to the right the equilibrium lies. 

Fluorine is unique among the halogens in forming no species in which it has a formal oxidation state other than — 1. The only known oxoacid is hypofluorous acid, HOF, which is unstable and does not ionize in water but reacts according to equation 16.54 no salts are known. It is obtained by passing F2 over ice at 230 K (equation 16.55) and condensing the gas produced. At 298 K, HOF decomposes rapidly (equation 16.56). 

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