1,4-Bis(4,5-dihydro-1H-imidazol-2-yl)benzene-4-amino-benzene-sulfonic acid-water (1/2/2).

The asymmetric unit of the title compound, C12H14N4·2C6H7NO3S·2H2O, contains one half of a centrosymmetric 1,4-bis­(4,5-dihydro-1H-imidazol-2-yl)benzene (bib) molecule, one 4-amino­benzene­sulfonic acid molecule and one water mol­ecule. In the bib molecule, the imidazole ring adopts an envelope conformation. The benzene rings of bib and 4-aminobenzenesulfonic acid are oriented at a dihedral angle of 21.89 (4)°. In the crystal structure, inter­molecular N—H⋯O, O—H⋯N and O—H⋯O inter­actions link the mol­ecules into a three-dimensional network. Weak π–π contacts between the benzene and imidazole rings and between the benzene rings [centroid–centroid distances = 3.895 (1) and 3.833 (1) A, respectively] may further stabilize the structure.