4,4'-Methyl-enedianilinium bis-(3-carb-oxy-4-hydroxy-benzene-sulfonate) monohydrate.

Co-crystallization of 4,4'-methyl-enediphenyl-amine (MDA) and 5-sulfosalicylic acid (5-H(2)SSA) yields the title salt, C(13)H(16)N(2) (2+)·2C(7)H(5)O(6)S(-)·H(2)O. The asymmetric unit is comprised of one dication, two anions and one water mol-ecule. In the crystal structure, the components of the salt are linked by a combination of inter-molecular O-H⋯O, N-H⋯O and weak C-H⋯O hydrogen bonds into a three-dimensional framework. In addition, two weak π-π inter-actions [with centroid-centroid distances of 3.8734 (15) and 3.7465 (15) Å] and one C-H⋯π inter-action further stabilize the crystal structure.