Bis(piperazinium) di-μ-chloro-penta­chloro­triiodo­dibismuthate(III) tetra­hydrate

The title salt, (C₄H₁₂N₂)₂[Bi₂Cl₇I₃]·4H₂O, was prepared by the reaction of bis­muth trichloride, potassium iodide and piperazine in a hydro­chloric acid medium. It is composed of piperazinium dications and dimeric [Bi₂Cl₇I₃]⁴⁻ tetra­anions, together with water of crystallization. The halobismuthate(III) tetra­anion is located on a center of inversion. Hydrogen bonds, including N—H...O, N—H...Cl, N—H...I, O—H...O, O—H...Cl and O—H...I inter­actions, are present in the crystal structure.