title: 2,2'-[(4,6-Dinitro-1,3-phenyl-ene)dioxy]diacetic acid hemihydrate.
abstract: The skeletons of both independent mol-ecules of the carboxylic acid hemihydrate, C(10)H(8)N(2)O(10)·0.5H(2)O, are approximately planar [maximum deviations 0.642 (3) and 0.468 (1) Å]. The deviations arise from the twisting of the nitro groups with respect to the aromatic rings [dihedral angles = 3.24 (2) and 27.01 (1), and 7.87 (1) and 16.37 (2)° in the two molecules]. The crystal structure features inter-molecular O-H⋯O hydrogen bonds, which the link the dicarboxylic acid and water mol-ecules into a supra-molecular layer network.
authors.affiliation: College of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, People's Republic of China.
authors.forename: Dong-Sheng
authors.initials: DS
authors.lastname: Ma
authors.forename: Xiu-Mei
authors.initials: XM
authors.lastname: Zhang
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Dan
authors.initials: D
authors.lastname: Mu
authors.forename: Guang-Feng
authors.initials: GF
authors.lastname: Hou