Tellurium Cations by Lewis Acid-Base Reactions: Syntheses and Crystal Structures of (Te24⊕)Zr2Br210⊖ and (TeBr3p⊕)(Zr2Br9⊖)
✍ Scribed by Beck, Johannes
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1991
- Tongue
- English
- Weight
- 417 KB
- Volume
- 124
- Category
- Article
- ISSN
- 0009-2940
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✦ Synopsis
Abstract
ZrBr~4~ reacts with Te~2~Br in a sealed evacuated ampoule at 210°C in quantitative yield to afford (Te^2^~4~^⊕^)(Zr~2~Br^2^~10~^⊖^) as blueblack, moisture‐sensitive crystals. The crystal‐structure determination shows, that (Te~4~)(Zr~2~Br~10~) consists of planar, nearly square Te^2^~4~^⊕^ and Zr~2~Br^2^~10~^⊖^ ions, that form edge‐sharing double octahedra. Both ions possess crystallographic 2/m (C~2~h) symmetry. At temperatures above 250°C (Te~4~)(Zr~2~Br~10~) decomposes with cleavage of Te –Te bonds into (TeBr~3~^⊕^)(Zr~2~Br~9~^⊖^), which forms yellow, hygroscopic crystals. (TeBr~3~)(Zr~2~Br~9~) can also be obtained by the reaction of two equivalents of ZrBr~4~ with TeBr~4~ at 260°C. The crystal structure is built of Zr~2~Br~9~^⊖^ ions, that form face‐sharing double octahedra, and of pyramidal TeBr~3~^⊕^ ions. Each TeBr~3~^⊕^ ion exhibits three Te – Br contacts to two different Zr~2~Br~9~^⊖^ ions, resulting in a strongly deformed octahedral coordination for the Te atom. The Zr~2~Br~9~ double octahedra and the TeCl~6~ octahedra are connected by common edges and corners to infinite chains.