The crystal structure of hexathallium(I) hexatellurodigermanate(III), Tl6[Ge2Te6]

Abstract The new compound Tl 6 [Ge 2 Te 6 ] was prepared by thermal synthesis from the elements. The material is triclinic, space group P 1 , with a = 9.471(2), b = 9.714(2), c = 10.389(2) A, α = 89.39(1), β = 97.27(1), γ = 100.79(1)°, and Z = 2. The crystal structure was determined from single-crystal intensity data measured by means of an automated four-circle diffractometer and refined to an R value of 0.053 for 1831 observed reflections. Tl 6 [Ge 2 Te 6 ] is characterized by Ge 2 Te 6 units with GeGe bonds which are linked into a three-dimensional structure by Tl atoms coordinated to essentially six Te atoms. The most important mean distances are d GeGe ) = 2.456 A, d ( GeTe ) = 2.573 A, and d ( TlTe ) = 3.515 A. The lone 6 s electron pairs of the thallium(I) atoms exhibit significant stereochemical activity. Tl 6 [Ge 2 Te 6 ] represents a new structure type.