Darstellung und Kristallstruktur von Tl₂TiS₄ : Ein Perthiotitanat(IV) mit _∞ ¹-[TiS₄ ^2-]-Ketten Preparation and Crystal Structure of Tl₂TiS₄ : A Perthiotitanate(IV) with _∞ ¹-[TiS₄ ^2-]-Chains

Abstract

Abstract Tl 2 TiS 4 is orthorhombic, space group Pbca, with a = 22.176(7), b = 9.484(4), c = 6.3977(9) Å, Z = 8. The crystal structure was solved by direct methods and refined to a conventional R of0.058 for 704 reflections with I ≥3σ(I). The crystal structure is characterized by infinite perthioanions, ∞ 1 -[TiS 4/2 (S2) 2- ], which are separated by Tl + -cations. The anion chains are built up by distorted octahedra which share two skew edges to form infinite cis-chains running along [001], The two unshared S-atoms of each octahedron are connected via a S -S-single bond of 2.10 Å length. The crystal structure is described as a mixed packing of TI-and S-atoms, composed of puckered TlS 2 -layers, in which the Ti-atoms occupy the octahedral interstices. The relationship of the ∞ 1 -[TiS 4 2- -]-chains to the anionic groups of Cs 2 TiS 3 is discussed.