Bis[1-(isopropyl­ideneamino)guanidinium] bis­(3-nitro­benzoate) monohydrate

The asymmetric unit of the title salt hydrate, 2C(4)H(11)N(4) (+)·2C(7)H(4)NO(4) (−)·H(2)O, comprises two independent 1-(isopropyl­ideneamino)guanidinium cations, two independent 3-nitro­benzoate anions and a water mol­ecule of crystallization. There are minimal geometric differences between the two planar [maximum deviations 0.061 (2) and 0.088 (2) Å] cations, and between the two almost planar anions [C–C–C–O and C–C–N–O torsion angles of 0.3 (3) and 11.1 (4) °, respectively in the first anion and −173.7 (2) and −0.1 (4), respectively in the second anion]. Extensive O—H⋯O and N—H⋯O hydrogen bonding between all components of the structure leads to the formation of a two-dimensional array with an undulating topology in the bc plane.