Polybismuthide Anions as Ligands: The Homoleptic Complex [(Bi7)Cd(Bi7)]4− and the Ternary Cluster [(Bi6)Zn3(TlBi5)]4−

We present the results from a reactivity study of the binary anion (TlBi₃)^2? towards Group 12 metal compounds MPh₂ (M=Zn, Cd, Hg) to gain access to coordination compounds of polycyclic polypnictide molecules such as Bi₇^3? or Bi₁₁^3?. The coordination chemistry of these polybismuthide cages has been unprecedented to date, while it has been known for a long time for the lighter Group 15 anions Pn₇^3? (Pn=P, As, Sb). The use of (TlBi₃)^2?, previously shown to release Tl under certain conditions in situ, resulted in the formation of the first heterometallic polyanion in which a nortricyclane‐type polybismuthide coordinates a transition‐metal atom, [(Bi₇)Cd(Bi₇)]^4?. Reactions with the lighter Group 12 metal precursor yielded the uncommon ternary cluster [(Bi₆)Zn₃(TlBi₅)]^4?, most likely representing a reaction intermediate, and at the same time hinting at the formation of the nortricyclane‐shaped cage. Quantum‐chemical studies provide deeper insight into the stability trends of the [(E₇)M(E₇)]^4? anion family and reveal a complex bonding situation in [(Bi₆)Zn₃(TlBi₅)]^4?, which features both localized and multi‐center bonding.