4-Nitro­anilinium triiodide monohydrate

In the title compound, C(6)H(7)N(2)O(2) (+)·I(3) (−)·H(2)O, the triiodide anions form two-dimensional sheets along the a and c axes. These sheets are separated by the 4-nitro­anilinium cations and water mol­ecules, which form part of an extended hydrogen-bonded chain with the triiodide along the c axis, represented by the graph set C (3) (3)(14). The second important hydrogen-bonding inter­action is between the nitro group, the water mol­ecule and the anilinium group, which forms an R (2) (2)(6) ring and may be the reason for the deviation of the torsion angle between the benzene ring and the nitro group from 180 to 163.2 (4)°. These two strong hydrogen-bonding inter­actions also cause the benzene rings to pack off-centre from one another, with an edge-on-edge π–π stacking distance of 3.634 (6) Å and a centroid–centroid separation of 4.843 (2) Å.