Halogen derivatives of oxoacids

Finally in this section we mention iodine oxide pentafluoride, F5IO, obtained as a colourless liquid, mp 45°, when IF7 is allowed to react with water, silica, glass or I2O5. As implied 

Numerous compounds are known in which the H atom of an oxoacid has been replaced by a halogen atom. Examples are  

The properties of halogen(I) perchlorates are in Table 17.25. FOCIO3 was originally prepared 

884 The Halogens Fluorine, Chlorine, Bromine, Iodine and Astatine 

The formation of isomers in this last reaction implies a low bond polarity of FO- in FOCIO3. 

In addition, halogen(III) derivatives such as Br(0N02)3, I(0N02)3, Br(0S02F 3 and I(OS02- 

F)4] (X=Br, I). In general, thermal stability decreases with increase in atomic number of the halogen. 

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This section considers compounds in which X (Cl, Br or I) is bonded to both O and F, i.e. F XOm. Oxofluorides -OF and peroxofluorides -OOF have already been discussed (p. 638) and halogen derivatives of oxoacids, containing -OX bonds are treated in the following section (p. 883). 

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