title: 3,3'-Diazenediyldiphthalic acid dihydrate.
abstract: In the crystal structure of the title compound, C(16)H(10)N(2)O(8)·2H(2)O, the organic mol-ecule is located on a centre of symmetry. The two benzene rings are parallel, but not coplanar, as indicated by N=N-C-C torsion angles involving the azo group of 12.1 (5) and -168.2 (3)°. The organic mol-ecule and the water mol-ecule are linked by O-H⋯O hydrogen bonds, forming a three-dimensional network.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Hou
authors.forename: Bao-Zhong
authors.initials: BZ
authors.lastname: Zhao
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu