2-((E)-{2-[(1E)-(2,4-Dihydroxy-benzyl-idene)amino]phen-yl}iminiometh-yl)-5-hydroxy-phenolate methanol solvate.

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)†à ] are also observed in the crystal structure.