Formation of [Bi11]3−, A Homoatomic, Polycyclic Bismuth Polyanion, by Pyridine‐Assisted Decomposition of [GaBi3]2−

Until now, polycyclic bismuth polyanions have not been known—thus discriminating bismuth from its lighter congeners. However, the synthesis of [K([2.2.2]crypt)]3(Bi11)⋅2 py⋅tol, allows us to present the first structurally characterized homoatomic, polycyclic bismuth polyanion, which exhibits the [P11]3− “ufosan” structure. It was obtained upon treatment of [K([2.2.2]crypt)]2(GaBi3)⋅en with the solvent pyridine. The binary Zintl anion [GaBi3]2− decomposes under oxidative coupling of pyridine molecules and release of H2 to form the title compound. The unprecedented reaction, its products and by-products were investigated by means of spectroscopy, spectrometry, and DFT studies. All findings reveal the specific reaction conditions to be crucial for the formation of the [Bi11]3− ion—and indicate the possibility of the generation and isolation of further, large bismuth polyanions.