Complexing between orthoperiodic acid and periodate ion in nitric acid solutions

Preparative synthesis techniques have been developed for four complex salts (Rb[H4IO6 · H5IO6], Cs[H4IO6 · H5IO6], Cs[H4IO6 · H5IO6 · 0.5H2O], and 2CsNO3 · HNO3 · H5IO6). In the Cs(Rb)NO3-H5IO6-HNO3-H2O systems, the starting component ratios, temperature schedules, and solvent-evaporation (H2O + HNO3) parameters have been determined to ensure the crystallization of the said compounds in individual states. For complex 2CsNO3 · HNO3 · H5IO6, solid-phase synthesis has also been developed. Highly water-sensitive Cs[H4IO6 · H5IO6] in the presence of water vapor converts to Cs[H4IO6 · H5IO6 · 0.5H2O].