title: 6,6'-Dihydr-oxy-2,2'-[(butane-1,4-diyldi-oxy)bis-(nitrilo-methyl-idyne)]diphenol.
abstract: The mol-ecule of the centrosymmetric title compound, C(18)H(20)N(2)O(6), assumes an E configuration with respect to the azomethine C=N bond. The imino group is coplanar with the aromatic ring. Intra-molecular O-H⋯O and O-H⋯N bonds are found between the hydroxyl groups and adjacent O (or N) atoms. In the crystal structure, inter-molecular O-H⋯O bonds link each mol-ecule to two others, forming a layered network.
authors.affiliation: School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, People's Republic of China.
authors.forename: Wen-Kui
authors.initials: WK
authors.lastname: Dong
authors.forename: Xue-Ni
authors.initials: XN
authors.lastname: He
authors.forename: Yin-Xia
authors.initials: YX
authors.lastname: Sun
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Yong-Hong
authors.initials: YH
authors.lastname: Guan