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2669400 
Journal Article 
Two New Cesium Thiotellurates: Cs-2[TeS2] and Cs-2[TeS3] 
Babo, JM; Wolff, KK; Schleid, T 
2013 
No 
Zeitschrift fuer Anorganische und Allgemeine Chemie
ISSN: 0044-2313 
639 
15 
2875-2881 
WOS:000328325000026 
Thermal decomposition of cesium azide (CsN3) leaves elemental cesium behind, which was in-situ produced and used for the syntheses of the two new cesium thiotellurates Cs-2[TeS2] and Cs-2[TeS3] along with appropriate amounts of tellurium and sulfur. The first compound crystallizes orthorhombically in space group Cmc2(1) with the lattice parameters a = 783.39(4), b = 1126.72(8), c = 823.04(5) pm (Z = 4) and the second one monoclinically in space group P2(1)/n with the lattice parameters a = 997.12(6), b = 1269.71(8), c = 1410.23(9) pm, = 91.218(3)degrees (Z = 8). While (1)-tetrahedral complex thiotellurate(IV) anions [TeS3](2-) are found as pyramids in Cs-2[TeS3], Cs-2[TeS2] comprises (2)-tetrahedral thiotellurate(II) units [TeS2](2-) as boomerangs and both occur isolated in the corresponding structures. In each of the title compounds, the anionic part of the structures is arranged layer-like with Cs+ cations sitting in between the layers. The cesium cations in the sulfur-rich compound Cs-2[TeS3] exhibit coordination numbers of seven and eight, while in the Cs-2[TeS2] these cations are surrounded by only six sulfide anions. But even the lone-pair electrons at the central Te4+ and Te2+ cations help to complete the Cs+ coordination spheres in both cases. 
Tellurium; Sulfur; Alkali metals; Crystal structure; Raman spectroscopy