Ultra-facile mechanochemical synthesis of sodium and silver metaperiodate at room temperature

Ultra-facile mechanochemical synthesis of single phase metaperiodates, AgIO4 and NaIO4, was achieved in a matter of minutes by gentle grinding of AgNO3 or NaNO3 with orthoperiodic acid, H5IO6, at room temperature. The reaction mechanism is hypothesised to involve the equilibrium between H5IO6 and HIO4, effected under the tribological conditions of grinding, leading to the release of H2O, production of metaperiodate species, and formation of the products by dissolution – precipitation, as evidenced by powder X-ray diffraction and Scanning Electron Microscopy data. Time resolved X-ray diffraction demonstrated that initial grinding of reagents, over 60 s, is sufficient to initiate the reaction. The mechanochemical method presented here meets the need for a simple, safe, scalable and sustainable approach to the synthesis of sodium and silver metaperiodates.