Diiodine pentoxide

There appears to be only one true oxide of iodine, diiodine pentoxide, IjOs- It is a white solid prepared by heating iodic acid(V) to 450 K ... 

The iodic acid(V) and some diiodine pentoxide separate out and the iodic(V) acid is purified by recrystallization from hot water. 

Kinetic smdies of the iodination of benzene and acetanilide by iodine, diiodine pentoxide, and sulfuric acid in acetic acid indicate that benzene is involved in an equilibrium reaction prior to the rate-limiting <7-complex formation." It is proposed that this equilibrium involves the formation of a itt-complex between iodine adsorbed on diiodine pentoxide and the benzene as it is adsorbed. In the case of acetanilide the a-complex is formed directly with activated iodine adsorbed on the diiodine pentoxide. 

Diiodine pentoxide may be prepared by thermal dehydration of iodic acid. 

Diiodine pentoxide is useful In devices such as respirators because it reacts with the dangerous gas carbon monoxide, CO, to produce relatively harmless CO2 according to the following equation ... 

Chlorine dioxide is usually made on-site to bleach flour and wood pulps and for water and waste treatment and is always kept well-diluted to decrease the chances of explosion. Dichlorine heptoxide, CI2O7 or O3CIOCIO3, is a shock-sensitive, oily liquid. It is formally the acid anhydride of perchloric acid. There are no stable bromine oxides at room temperatures. Of the iodine oxides, diiodine pentoxide, I2O5, is the most important. It is used to quantitatively determine carbon monoxide concentrations by the reaction represented in Equation (18.27) ... 

Although periodic acid is known (Section 6.6), I2O7 is not. The highest known normal oxide of iodine is diiodine pentoxide, I2O5, which can be made by the dehydration of the white crystals of iodic acid, HIO3, which is itself obtained by the oxidation of iodine with nitric acid. Dehydration is achieved by heating in a stream of dry air ... 

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