PERIODIC ACID FOR SYNTHESIS
PERIODIC ACID FOR SYNTHESIS
The periodic acid is reduced to iodic acid (HIO3). Because vicinal diols are obtained from alkenes, the combination of dihydroxylation followed by oxidative cleavage of a diol provides an alternative method to ozonolysis of alkenes to yield the same products.
Periodic acid is the highest oxoacid of iodine, in which the iodine exists in oxidation state +7. Like all periodates it can exist in two forms: orthoperiodic acid, with the chemical formula H5IO6 and metaperiodic acid, which has the formula HIO4.
Further heating to around 150 °C gives iodine pentoxide (I2O5) rather than the expected anhydride diiodine heptoxide (I2O7). Metaperiodic acid can also be prepared from various orthoperiodates by treatment with dilute nitric acid.
Modern industrial scale production involves the oxidation of a solution of sodium iodate under alkaline conditions, either electrochemically on a PbO2 anode, or by treatment with chlorine
