3,4,5-Trihy­droxy­benzohydrazidium perchlorate–3,4,5-trihy­droxy­benzohydrazide–water (1/1/1)

The crystal studied of the title compound, C(7)H(9)N(2)O(4) (+)·ClO(4) (−)·C(7)H(8)N(2)O(4)·H(2)O, was found to be a racemic twin with a 0.72 (18):0.28 (18) domain ratio. The hydrazidium group is close to planar, with an r.m.s deviation of 0.105 Å; the hydrazide group deviates more from planarity, with an r.m.s deviation of 0.174 Å. In the crystal, the hydrazidium cation, hydrazide mol­ecule, perchlorate anions and water mol­ecules are linked through O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds into a three-dimensional supra­molecular network. In addition, the benzene rings of the hydrazidium and hydrazide units are connected via π–π inter­actions into infinite chains along the c axis; the centroid–centroid distances are 3.486 (3) and 3.559 (3) Å.