NEW POLYOXOTANTALATE SALT Na<sub>8</sub>[Ta<sub>6</sub>O<sub>19</sub>]·24.5H<sub>2</sub>O and its properties
The interaction of Ta<sub>2</sub>O<sub>5</sub> with sodium hydroxide at 400°C yields Na<sub>8</sub>[Ta<sub>6</sub>O<sub>19</sub>], which can be recrystallized from an aqueous solution in the form of Na<sub>8</sub>[Ta<sub>6</sub>O<sub>19</sub>]·24.5H<sub>2</sub>O. The complex is characterized by IR spectroscopy, thermogravimetry, powder XRD, and single crystal XRD: hexagonal system, <i>P</i>6<sub>3</sub> space group, <i>a</i> = 12.3622(2) Å, <i>c</i> = 31.4305(7) Å, <i>V</i> = 4159.81(13) Å<sup>3</sup>, <i>d</i><sub>x</sub> = 3.217 g/cm<sup>3</sup>, <i>R</i> = 0.0195.