Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Well ordered single crystals of TaI<jats:sub>5</jats:sub> (orthorhombic, <jats:italic>Pnma</jats:italic> (no. 62), <jats:italic>a</jats:italic> = 1396.2(2), <jats:italic>b</jats:italic> = 2009.5(4), <jats:italic>c</jats:italic> = 660.7(1) pm, Z = 8, R<jats:sub>1</jats:sub> for 967 reflections with I<jats:sub>0</jats:sub>>2σ(I<jats:sub>0</jats:sub>): 0.0381) were obtained from a reaction of the elements. The structure determination confirms Müller's prediction of 1978. Single crystals of CsTaI<jats:sub>6</jats:sub> (monoclinic, <jats:italic>C</jats:italic>2/<jats:italic>c</jats:italic> (no. 15), <jats:italic>a</jats:italic> = 1362.3(2), <jats:italic>b</jats:italic> = 709.9(1), <jats:italic>c</jats:italic> = 1736.2(3) pm, <jats:italic>β</jats:italic> = 128.77(1)°, Z = 4, R<jats:sub>1</jats:sub> for 1140 reflections with I<jats:sub>0</jats:sub>>2σ(I<jats:sub>0</jats:sub>): 0.0378) were obtained by the oxidation of tantalum with CsI<jats:sub>3</jats:sub>. Both crystal structures contain [TaI<jats:sub>6</jats:sub>] octahedra which are edge‐connected to Ta<jats:sub>2</jats:sub>I<jats:sub>10</jats:sub> dimers in TaI<jats:sub>5</jats:sub> and isolated as [TaI<jats:sub>6</jats:sub>]<jats:sup>−</jats:sup> anions in the salt Cs[TaI<jats:sub>6</jats:sub>] (CsWCl<jats:sub>6</jats:sub> type of structure).</jats:p>