title: 2,2'-(2,2'-Biimidazole-1,1'-di-yl)diethanoic acid.
abstract: In the title compound, C(10)H(10)N(4)O(4), the two imidazole rings adopt a trans conformation and are inclined to one another at a dihedral angle of 55.64 (4)°. In the crystal structure, mol-ecules are linked by inter-molecular O-H⋯N hydrogen bonds into chains running parallel to [010] and layers are formed from these by inter-molecular C-H⋯O hydrogen bonds. Additional C-H⋯O hydrogen bonds produce a three-dimensional network.
authors.affiliation: State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, People's Republic of China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Yingtao
authors.initials: Y
authors.lastname: Ren
authors.forename: Hongze
authors.initials: H
authors.lastname: Liang