title: 2-((E)-{2-[(1E)-(2,4-Dihydroxy-benzyl-idene)amino]phen-yl}iminiometh-yl)-5-hydroxy-phenolate methanol solvate.
abstract: The asymmetric unit of the title compound, C(20)H(16)N(2)O(4)·CH(3)OH, contains two Schiff base zwitterions and two methanol solvent mol-ecules. The dihedral angles between the central benzene ring and the two outer benzene rings of the Schiff base are 2.57 (7) and 52.30 (7)° in one mol-ecule and 5.83 (7) and 49.82 (7)° in the other mol-ecule. Intra-molecular O-H⋯N and N-H⋯O hydrogen bonds generate S(6) ring motifs, whereas intra-molecular N-H⋯N hydrogen bonds generate S(5) ring motifs. In the crystal structure, O-H⋯O, hydrogen bonds and weak C-H⋯O inter-actions link the mol-ecules into one-dimensional chains along the b-axis direction and are further connected by O-H⋯O and weak C-H⋯O inter-actions into a three-dimensional network. C-H⋯π and π-π inter-actions [centroid-centroid distances = 3.6228 (9) and 3.6881 (9) Å] are also observed in the crystal structure.
authors.forename: Naser Eltaher
authors.initials: NE
authors.lastname: Eltayeb
authors.forename: Siang Guan
authors.initials: SG
authors.lastname: Teoh
authors.forename: Suchada
authors.initials: S
authors.lastname: Chantrapromma
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun
authors.forename: Rohana
authors.initials: R
authors.lastname: Adnan