A monoclinic polymorph of (1E,5E)-1,5-bis­(2-hy­droxy­benzyl­idene)thio­carbono­hydrazide

The title compound, C(15)H(14)N(4)O(2)S, is a derivative of thio­ureadihydrazide. In contrast to the previously reported polymorph (ortho­rhom­bic, space group Pbca, Z = 8), the current study revealed monoclinic symmetry (space group P2(1)/n, Z = 4). The mol­ecule shows non-crystallographic C (2) as well as approximate C (s) symmetry. Intra­molecular bifurcated O—H⋯(N,S) hydrogen bonds, are present. In the crystal, inter­molecular N—H⋯S hydrogen bonds and C—H⋯π contacts connect the mol­ecules into undulating chains along the b axis. The shortest centroid–centroid distance between two aromatic systems is 4.5285 (12) Å.