In the 4-nitro-benzene sulfonate anion of the title compound, C(2)H(4)N(3) (+)·C(6)H(4)NO(5)S(-)·H(2)O, the nitro group is slightly twisted from the plane of the benzene ring [dihedral angle = 2.8 (3)°]. In the crystal, the three components are linked via N-H⋯O, O-H⋯N, O-H⋯O and C-H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane. A short inter-molecular O⋯N contact of 2.872 (3) Å is also observed between the nitro and sulfonate groups.
* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.