Homocyclic Tellurium Cations

Tellurium forms the most extensive series of homoatomic chalcogen cations. The list of structurally characterised tellurium polycations includes Te4, 6, Te6, Teg and Teg and also the polymeric species (Te4 ) , 

The eight-atom systems provide a compelling illustration of the structural diversity of tellurium polycations. There are examples of (a) structural isomers of the monomeric dication Tcg, (b) a polymeric (Teg ) cation and (c) a tetracation Teg . Unlike cyclo-Sg and -Seg , the Teg dication cannot be made by oxidising tellurium with MF5 (M = As or Sb) in liquid SO2. However, the reactions of (a) the tellurium subhalide Te3Cl2 with ReC at 200 °C and (b) tellurium with WCl6 at 180°C produce the salts Teg[MCl6] (w=l, M = Re  

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