Synthesis and crystal structure of [Li(NH3)4]4[Sn9]·NH3 and [Li(NH3)4]4[Pb9]·NH3 †

Zusammenfassung

The reduction of an excess of Sn or Pb with a concentrated solution of Li in liquid ammonia yielded black crystals of [Li(NH3)(4)](4)[Sn-9]. NH3 or [Li(NH3)(4)](4)[Pb-9]. NH3 as main product, respectively. The compounds are isotypic and crystallise in space group P2(1)/c. They contain the isolated Zintl anions Sn-9(4-) and Pb-9(4-), which form slightly distorted monocapped square antiprisms. The lead compound is the first example of a "naked" Pb-9(4-) cage without contacts to metal atoms.