Tris(ethylenediamine)cobalt(III) nonaiododibismuthate

The asymmetric unit of the title compound, [Co(C2H8N2)3][Bi2I9], crystallizes in the ortho­rhom­bic space group Cmc21. The asymmetric unit contains half of a [Co(en)3]3+ cation (en is ethyl­enediamine) and half of a [Bi2I9]3− anion. Both species are located on mirror planes, requiring the [Co(en)3]3+ cation to be present as a statistically disordered mixture of both enantiomeric forms. Crystals were grown solvothermally from an ethanol–water solvent mixture using rac-[Co(en)3]I3 and bis­muth triiodide as starting materials. The compound is a rare example of a mixed-metal halobismuthate material.