Synthesis and properties of thallium(III) periodate

The reaction of [Tl(H2O)6]3+ with H5IO6 in aqueous acid solution over a range of pH produces the insoluble orange–brown Tl5(IO6)3, which has been characterised by analysis, IR and UV–Vis spectroscopy. The compound is amorphous, but I K- and Tl LIII edge EXAFS studies identify IO6 and TlO6 as the structural units present and a possible structure is proposed. The Tl(III)–IO6 system is compared with literature data on gallium and indium periodate complexes.