Preparation and crystal structure of thallium thiotitanate (Tl4TiS4), thallium thiostannate (Tl4SnS4), and thallium selenotitanate (Tl4TiSe4)
- Publication Type
- Journal contribution
- Authors
- Klepp, K. O.; Eulenberger, G.
- Year of publication
- 1984
- Published in
- Z. Naturforsch., B: Anorg. Chem., Org. Chem.
- Band/Volume
- 39B/6
- Page (from - to)
- 705-12
The isostructural Tl4TiS4, Tl4SnS4, and Tl4TiSe4 crystallize in the monoclinic system, space group P21/c with a 8.328, b 8.191, c 15.248.ANG., .beta. 104.53.degree.; a 8.395, b 8.2808 c 15.398 .ANG., .beta. 103.69.degree., and a 8.517, b 8.389, c 15.672 .ANG., .beta. 103.50.degree., resp. with Z = 4. They are characterized by isolated tetrahedral thioanions which are connected with each other by Tl+ ions. The mean bond lengths are Ti-S = 2.26 .ANG., Sn-S =2.40 .ANG., and Ti-Se = 2.38 .ANG.. The Tl atoms are surrounded by 6 and 7 chalcogen atoms, resp., in an irregular and polar arrangement, thus indicating stereochem. activity of the lone electron pair of the Tl+ ions. Tl-S distances vary from 2.93 to 3.98 .ANG., Tl-Se distances from 3.03 to 3.96 .ANG.. The Tl atoms have nearest Tl neighbors at distances 3.46-3.65 .ANG.. The crystal structure can be described as built from pseudotetragonal slabs oriented parallel to (001) which contain the cations and the tetrahedral anions. A similar description is valid also for the crystal structures of Tl4GeS4 and Na4SnS4.