title: 2,2'-Dihydroxy-3,3'-[(1E,1'E)-hydrazine-1,2-diylidenedimethylidyne]dibenzoic acid N,N-dimethylformamide disolvate.
abstract: The title compound, C(16)H(12)N(2)O(6)·2C(3)H(7)NO, lies across a crystallographic inversion centre which is situated at the midpoint of the central N-N bond. The substitution at the C=N bond adopts a trans configuration and it is essentially coplanar with the benzene ring [N-C-C-C torsion angles = -173.9 (4) and 6.4 (6)°]. All torsion angles involving non-H atoms are close to 180°. Intra-molecular O-H⋯O and weak C-H⋯O hydrogen bonds form S(6) and S(5) ring motifs, respectively, while inter-molecular O-H⋯O and weak C-H⋯O hydrogen bonds connect the Schiff base mol-ecule to solvent dimethyl-formamide mol-ecules.
authors.affiliation: College of Pharmacy, Gannan Medical University, Ganzhou, Jiangxi 341000, People's Republic of China.
authors.forename: Sheng-Sen
authors.initials: SS
authors.lastname: Zhang
authors.forename: Geng-Jin-Sheng
authors.initials: GJ
authors.lastname: Cheng
authors.forename: Yu
authors.initials: Y
authors.lastname: Lei
authors.forename: Yin-Bao
authors.initials: YB
authors.lastname: Li