Halobismuth(III) salts with substituted aminopyridinium cations

The crystal structures of six halobismuth(III) salts of variously substituted aminopyridinium cations display discrete mononuclear BiCl₆]^3? and dinuclear Bi₂X₁₀]^4? anions (X = Cl or Br), and polymeric cis‐double‐halo‐bridged Bi_nX_4n]^n? anionic chains (X = Br or I). Bis(2‐amino‐3‐ammoniopyridinium) hexachloridobismuth(III) chloride monohydrate, (C₅H₉N₃)₂BiCl₆]Cl·H₂O, (1), contains discrete mononuclear BiCl₆]^3? and chloride anions. Tetrakis(2‐amino‐3‐methylpyridinium) di‐μ‐chlorido‐bistetrachloridobismuth(III)], (C₆H₉N₂)₄Bi₂Cl₁₀], (2), tetrakis(2‐amino‐3‐methylpyridinium) di‐μ‐bromido‐bistetrabromidobismuth(III)], (C₆H₉N₂)₄Bi₂Br₁₀], (3), and bis(4‐amino‐3‐ammoniopyridinium) di‐μ‐chlorido‐bistetrachloridobismuth(III)] dihydrate, (C₅H₉N₃)₂Bi₂Cl₁₀]·2H₂O, (4), incorporate discrete Bi₂X₁₀]^4? anions (X = Cl or Br), while catena‐poly2,6‐diaminopyridinium cis‐diiodidobismuth(III)]‐di‐μ‐iodido]], {(C₅H₈N₃)BiI₄]}_n, (5), and catena‐poly2,6‐diaminopyridinium cis‐dibromidobismuth(III)]‐di‐μ‐bromido]], {(C₅H₇N₂)BiBr₄]}_n, (6), include Bi_nX_4n]^n? anionic chains (X = Br or I). Structures (2) and (3) are isostructural, while that of (5) is a pseudomerohedral twin. There is no discernible correlation between the type of anionic species obtained and the cation or halide ligand used. The Bi^III centres always have a slightly distorted octahedral geometry and there is a correlation between the Bi—X bond lengths and the number of classic N—H…X hydrogen bonds that the X ligand accepts, with a greater number of interactions corresponding with slightly longer Bi—X distances. The supramolecular networks formed by classic N—H…X hydrogen bonds include ladders, bilayers and three‐dimensional frameworks.