title: 4,4'-{[1,2-Phenyl-enebis(methyl-ene)]bis-(-oxy)}di-benzoic acid di-methyl-formamide disolvate.
abstract: In the title solvate, C22H18O6·2C3H7NO, the complete dicarboxylic acid molecule is generated by a crystallographic twofold axis, which bisects the central benzene ring and one N,N-di-methyl-formamide solvent mol-ecule. The dihedral angle between the central and pendant benzene rings is 54.53 (5)° while that between the pendant rings is 45.44 (5)°. In the crystal, the acid molecules are linked to the solvent molecules via O-H⋯O and weak C-H⋯O hydrogen bonds. Further weak C-H⋯O inter-actions link adjacent acid mol-ecules into a three-dimensional network.
authors.affiliation: Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650050, People's Republic of China.
authors.forename: Zhen-Zhe
authors.initials: ZZ
authors.lastname: Qiu
authors.affiliation: Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650050, People's Republic of China.
authors.forename: Bi
authors.initials: B
authors.lastname: Jing
authors.affiliation: Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650050, People's Republic of China.
authors.forename: Qiu-Xia
authors.initials: QX
authors.lastname: Li
authors.affiliation: Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650050, People's Republic of China.
authors.forename: Ai-Xin
authors.initials: AX
authors.lastname: Zhu