The crystal structure of Tl2[Ge2S4], a ternary thallium(I) sulfide with divalent and tetravalent germanium
- Publikations-Art
- Zeitschriftenbeitrag
- Autoren
- Eulenberger, G.
- Erscheinungsjahr
- 1985
- Veröffentlicht in
- J. Less-Common Met.
- Band/Volume
- 108/1
- Seite (von - bis)
- 65-72
Tl2[Ge2S4] is orthorhombic, space group Pmnb with a 6.633(2), b 8.824(2), and c 13.977(4) .ANG.; and d.(calcd.) = 5.54 for Z = 4. Final R = 0.044 (Rw = 0.036). At. coordinates are given. The structure is characterized by infinite double chains Ge2IIGe2IVS84- parallel to [100] which are held together by Tl+ cations situated between them. The double chains are composed of single chains contg. alternately divalent and tetravalent Ge atoms linked by S atoms. These single chains are linked in pairs by S bridges between the Ge(II) and Ge(IV) atoms. The divalent Ge atoms are each bonded to 3 S atoms, thus forming .psi.-tetrahedral GeS3 arrangements (mean Ge-S distance 2.355 .ANG.). The tetravalent Ge atoms are tetrahedrally coordinated to 4 S atoms (mean Ge-S distance 2.224.ANG.). The 9 S atoms around Tl(2) form a distorted tricapped trigonal prism. The same configuration is adopted by 8 S atoms and 1 Ge(II) atom around Tl(1). The mean Tl-S distance is 3.437 .ANG. and the Tl-GeII distance is 3.133 .ANG., with the lone pair of electrons directed towards the Tl atom.