5-[(E)-(2-Hydroxybenzylidene)amino]-1H-1,3-benzimidazole-2(3H)-thione

There are two molecules in the asymmetric unit of the title compound, C14H11N3OS. In each, the benzimidazole ring system is essentially planar, with maximum deviations of 0.010 (2) and 0.006 (2) Å, and makes dihedral angles of 8.70 (9) and 13.75 (8)°, respectively, with the hydroxy-substituted benzene rings. Each molecule adopts an E configuration about the central C=N double bond. In the crystal, the two independent molecules are connected via intermolecular N—H...S hydrogen bonds, forming dimers. Furthermore, the dimers are connected by N—H...O hydrogen bonds into molecular ribbons along the c axis. There is an intramolecular O—H...N hydrogen bond in each molecule, which generates an S(6) ring motif