Synthesis and crystal structure of α-ThTe₃

The binary thorium tritelluride, α-ThTe₃, was synthesized by solid-state methods at 1223 K. From a single-crystal X-ray diffraction study the material crystallizes in the TiS₃ structure type with two formula units in space group C²_2h-P2₁/m of the monoclinic system in a cell with lattice constants a = 6.1730 (4) Aa, b = 4.3625(3) Aa, c = 10.4161(6) Aa, and β = 97.756(3) (at 100 K). The asymmetric unit of this compound comprises one Th atom and three Te atoms each with site symmetry m. Each Th atom is coordinated to eight Te atoms in a bicapped trigonal-pyramidal arrangement. Th-Te distances range from 3.1708(4) Aa to 3.2496(6) Aa. The structure features a Te-Te interaction 2.7631(8) Aa in length, which is typical for a Te-Te single bond. Thus α-ThTe₃ may be charge balanced and formulated as Th⁴⁺Te^2-Te₂^2-. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)