Crystal structure and Hirshfeld surface analysis of the hydrated 2:1 adduct of piperazine-1,4-diium 3,5-di­nitro-2-oxidobenzoate and piperazine

The crystal structure of the adduct piperazine-1,4-diium 3,5-di­nitro-2-oxidobenzoate–piperazine–water (2/1/2) shows the existence of a 3,5-di­nitro­salicylate dianion (DNSA(2−)) and a protonated piperazine-1,4-diium cation (PIP(2+)) along with a piperazine mol­ecule. The formula of the title adduct in the asymmetric unit is 2C(4)H(12)N(2) (2+)·2C(7)H(2)N(2)O(7) (2−)·C(4)H(10)N(2)·2H(2)O with Z = 1. The piperazine ring in the piperazine-1,4-diium cation and in the neutral piperazine mol­ecule adopt chair conformations. All O atoms in the DNSA(2−) moiety and the water mol­ecule act as hydrogen-bonding acceptors for various inter­molecular O—H⋯O, N—H⋯O and C—H⋯O inter­actions, which stabilize the crystal structure. Various supra­molecular architectures formed by the different inter­molecular inter­actions are discussed. The relative contribution of various inter­molecular contacts is analysed with the aid of two-dimensional (full and decomposed) fingerprint plots, indicating that H⋯O/O⋯H (50.2%) and H⋯H (36.2%) contacts are the major contributors to the stabilization of the crystal structure.