Metal Assisted Synthesis of Cationic Sulfidobismuth Cubanes in Ionic Liquids

Bi2S3 was dissolved in the presence of either AuCl/PtCl2 or AgCl in the ionic liquids [BMIm]Cl ⋅ xAlCl3 (BMIm=1‐n‐butyl‐3‐methylimidazolium; x=4–4.3) through annealing the mixtures at 180 or 200 °C. Upon cooling to room temperature, orange, air‐sensitive crystals of [BMIm](Bi4S4)[AlCl4]5 (1) or Ag(Bi7S8)[S(AlCl3)3]2[AlCl4]2 (2) precipitated, respectively. 1 did not form in the absence of AuCl/PtCl2, suggesting an essential role of the metal cations. X‐ray diffraction on single‐crystals of 1 revealed a monoclinic crystal structure that contains (Bi4S4)4+ heterocubanes and [AlCl4]− tetrahedra as well as [BMIm]+ cations. The intercalation of the ionic liquid was confirmed via solid state NMR spectroscopy, revealing unusual coupling behavior. The crystal structure of 2 consists of (Bi7S8)5+ spiro‐dicubanes, [S(AlCl3)3]2− tetrahedra triples, isolated [AlCl4]− tetrahedra, and heavily disordered silver(I) cations. No cation ordering took place in 2 upon slow cooling to 100 K. Two new compounds containing sulfidobismuth cubane or spiro‐dicubane cations were obtained from metal assisted ionothermal syntheses. Fine‐tuning of the composition of the reaction mixture including the ionic liquid proved to be essential for successful syntheses.