The supra­molecular architecture of tris­(naphthalene-1,5-diaminium) bis­(5-amino­naphthalen-1-aminium) octa­kis­[hydrogen (5-carb­oxy­pyridin-3-yl)phosphon­ate]

The asymmetric unit of the title compound, 3C₁₀H₁₂N₂²⁺·2C₁₀H₁₁N₂⁺·8C₆H₅NO₅P⁻, contains one and a half naphthalene-1,5-diaminium cations, in which the half-mol­ecule has inversion symmetry, one 5-amino­naphthalen-1-aminium cation and four hydrogen (5-carb­oxy­pyridin-3-yl)phosphon­ate anions. The crystal structure is layered and consists of hydrogen-bonded anionic monolayers between which the cations are arranged. The acid mono­anions are organized into one-dimensional chains along the [101] direction via hydrogen bonds established between the phosphon­ate sites. (C)O—H...N_py hydrogen bonds (py is pyridine) crosslink the chains to form an undulating (010) monolayer. The cations serve both to balance the charge of the anionic network and to connect neighbouring layers via multiple hydrogen bonds to form a three-dimensional supra­molecular architecture.