Crystal structure of octane-1,8-diaminium 4,4'-(diazene-1,2-di-yl)dibenzoate monohydrate.

The title salt, C8H22N22+·C14H8N2O42-·H2O, represents a pseudo-polymer ionic material, resulting from the self-organizing behavior of 4,4'-azinodibenzoate dianions and doubly protonated, 1,8-diaminium-octane cations in aqueous solution. The asymmetric unit consists of two halves of octane 1,8-diaminium cations (the complete cations are both generated by crystallographic inversion symmetry), a 4,4'-azinodibenzoate anion [dihedral angle between the aromatic rings = 10.22 (4)°] and a water mol-ecule of crystallization. One of the cations is in a fully extended linear conformation while the second one has a terminal C-C-C-N gauche conformation. In the crystal, the cations, anions and water mol-ecules are linked into a three-dimensional network via a complex pattern of charge-assisted N-H⋯O and O-H⋯O hydrogen bonds.