Transition metal iodates. VI. Preparation and characterization of the larger lanthanide iodates

In the continuation of this work, the Ln^III(IO₃)₃xH₂O type N compounds (abbreviated x_N) of La through Sm were prepared by precipitation, thermal decomposition, and by crystallization from the gel, from ambient and boiling water, and from boiling HNO₃. A total of 36 different compounds with 6 ? x ? 0 were obtained occurring in 12 structural types including one amorphous; in addition La₅(IO₆)₃ and four isostructural double salts of the type Ln(IO₃)₃·HIO₃ were obtained.Characterization techniques used included powder X-ray diffraction, differential thermal analysis, thermogravimetric analysis, second harmonic generation, and infrared spectroscopy.Out of the total of 16 crystalline iodate structures occurring for all the lanthanides, single crystals were obtainable in 11, comprising a total of 54 compounds.Including all the lanthanides (plus Y, less Pm), the x_N groups of isostructural compounds, with the number of compounds in parentheses, were the following: 6(1), 5_I(4), 5_II(2), 4(9), amorphous with 5 ? x ? 0 (15), 2_I(3), 2_II(9), 1(4), $\text{1}\text{2}\text{(2)}$, O_I(14), O_II(2), O_III(4), O_IV(3), O_V(4), and O_VI(1).