{Sn₉[Si(SiMe₃)₃]₃}⁻ and {Sn₈Si[Si(SiMe₃)₃]₃}⁻: Variations of the E₉ Cage of Metalloid Group 14 Clusters

The disproportionation reaction of the subvalent metastable halide SnBr proved to be a powerful synthetic method for the synthesis of metalloid cluster compounds of tin. Hence, the neutral metalloid cluster compound Sn₁₀[Si­(SiMe₃)₃]₆ (3) was synthesized from the reaction of SnBr with LiSi­(SiMe₃)₃. In the course of the reaction anionic clusters might also be present, and we now present the first anionic cluster compound {Sn₈E­[Si­(SiMe₃)₃]₃}⁻ (E = Si, Sn), where one position in the cluster core is occupied by a silicon or a tin atom, giving further insight into structural variations of E₉ cages in metalloid group 14 cluster compounds.