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

There are two mol­ecules in the asymmetric unit of the title compound, C(14)H(11)N(3)OS. 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.