Quinolinium 8-hy­droxy-7-iodo­quinoline-5-sulfonate 0.8-hydrate

In the crystal structure of the title hydrated quinolinium salt of ferron (8-hy­droxy-7-iodo­quinoline-5-sulfonic acid), C(9)H(7)N(+)·C(9)H(5)INO(4)S(−)·0.8H(2)O, the quinolinium cation is fully disordered over two sites (occupancy factors fixed at 0.63 and 0.37) lying essentially within a common plane and with the ferron anions forming π–π-associated stacks down the b axis [minimum ring centroid separation = 3.462 (6) Å]. The cations and anions are linked into chains extending along c through hy­droxy O—H⋯O and quinolinium N—H⋯O hydrogen bonds to sulfonate O-atom acceptors which are also involved in water O—H⋯O hydrogen-bonding inter­actions along b, giving a two-dimensional network.