Preparation and crystal structure of dithallium(I) lead(II) tetrathiogermanate(IV) Tl2PbGeS4

Publikations-Art

Zeitschriftenbeitrag

Autoren

Eulenberger, G.

Erscheinungsjahr

1980

Veröffentlicht in

Z. Naturforsch., B: Anorg. Chem., Org. Chem.

Band/Volume

35B/3

Seite (von - bis)

335-9

Tl2PbGeS4 was prepd. by fusion of a stoichiometric mixt. of Tl2S, PbS, and GeS2, and prolonged heating of the reaction product. A single crystal could be isolated for intensity measurements on an automated four-circle single-crystal diffractometer. Tl2PbGeS4 is monoclinic, space group P21/a, with a 8.907(2), b 9.114(2), c 10.502(3) .ANG., .beta. 94.08(2).degree., and Z = 4. The crystal structure was detd. by means of std. methods and refined to R = 0.065. The structure is composed of tetrahedral [GeS4]4- anions which are held together by Tl+ and Pb2+ cations. The GeS4 tetrahedra are only slightly deformed (mean distance Ge-S = 2.220 .ANG.). The Tl atoms are surrounded by 8 S atoms at distances of 3.085-4.055 .ANG. forming irregular coordination polyhedra. The Pb atom is coordinated by 6 S atoms in a strongly distorted octahedral arrangement at distances of 2.803-3.256 .ANG.. The Pb atoms and the Tl(2) atoms are alternately situated between slabs of GeS4 tetrahedra parallel to the ab plane. The Tl(1) atoms are found within these slabs located between the GeS4 tetrahedra.