Platinum Metals Rev., 1969, 13, (4), 152
Iridium Iodate: A New Complex
The iodates of quadrivalent elements such as cerium, zirconium and thorium have, as would be expected, a stoichiometry of M(IO3)4. A short paper by Professor G. Wilkinson and D. Rose of the Inorganic Chemistry Laboratories, Imperial College, and F. M. Lever and A. R. Powell of the Johnson Matthey Research Laboratories (J.Chem.Soc. (A ), 1969, 1690) describes the preparation and characterisation of iridium (IV) iodate, produced by the reaction of sodium iodate with a perchloric acid solution of iridium. The reaction yields a quantitative precipitate of an amorphous bluish-black complex. This seems to be a unique compound and entirely different from the iodates of other quadrivalent elements, having only one iodate radical for each iridium atom.
It is suggested that the compound is a polymeric bridged iodate complex IrIO3(OH)3 formed by the following mechanisms: