Tellurium Polycations Stabilized by Halogenobismutates – Syntheses and Crystal Structure of te 4 [bi 6 Cl 20 ] and te 4 [bi 2 br 8 ]

The reaction of Te, TeX 4 and BiX 3 [X = Cl, Br] in sealed, evacuated glass ampoules in the temperature range 170° 100°C yields a variety of compounds composed of tellurium polycations and halobismutate anions. Two of these have been identified by crystal structure analyses as Te 4 [Bi 6 Cl 20 ] (triclinic, P ., a = 738.8(2), b = 875.1(2), c = 1389.1(6) pm, α = 87.89(2), β = 82.87(4), γ = 87.89(2) ·, Z = 1) and Te 4 [Bi 2 Nr 8 (triclinic, P ., a = 726.0(4), b = 773.7(4), c = 901.8(5) pm, α = 92.95(2), β = 102.23(2), γ = 92.87(2)., Z = 1). Both compounds were obtained as black crystals with a violet lustre and contain square‐planar Te 4 2+ cations. Te 4 [Bi 6 Cl 20 ] contains a two‐dimensional polymeric anion [Bi 6 Cl 20 ] 2− made up of corner‐ and edge‐sharing BiCl 6 octahedra with attached BiCl 3 groups. The Bi–Cl distances vary over a very wide range from 245 to 334 pm. Te 4 [Bi 2 Br 8 ] consists of a onedimensional chain [BiBr 2 Br 4/2 − [ n of cis ‐edge‐connected BiBr 6 octahedra with Bi–Br distances ranging from 264 to 318 pm.