The title compound, [MoO2(C14H9N2O2Br)H2O]·C3H7NO, has a three-dimensional supra­molecular arrangement via a number of inter­molecular C—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, as well as C—H⋯π and π–π inter­actions.

In the title compound, C14H9Cl2N3O4·C3H7NO, the hydrazone mol­ecule adopts an E conformation with respect to azomethine bond, and the dihedral angle between the two aromatic rings [8.96 (11)°] shows that the rings are almost co-planar. The planar conformation of the mol­ecule is stabilized by the intra­molecular O—H⋯N hydrogen bond involving the OH group and azomethine N atom. The azomethine and keto bond distances [1.269 (2) and 1.210 (2) Å, respectively] are very close to the formal C=N and C=O bond lengths. The di­methyl­formamide solvent mol­ecule is connected to the hydrazone NH group via an N—H⋯O hydrogen bond. In the crystal, non-classical C—H⋯O and C—H⋯Cl hydrogen bonds link the mol­ecules into chains along [322]. A supra­molecular three-dimensional architecture is created by weak C—Cl⋯π [4.163 (3) Å, 83.26 (9)°] and π–π [centroid–centroid distance = 4.0395 (14) Å] inter­actions.

The title azine mol­ecule, C28H24N2O4, lies about a center of inversion. The dihedral angle between the phenyl ring and the hy­droxy-substituted ring is 70.3 (5)°. The phenolic O–H group forms an intra­molecular hydrogen bond to the azine N atom.

The title compound, C21H19N3O2S, exists in the thione form. The configuration about the C=N bond is E. The hydrazinecarbothio­amide unit adopts an almost planar arrangement, with maximum deviations of 0.016 (3) and −0.016 (2) Å for the two thio­urea N atoms. An intra­molecular O—H⋯N hydrogen bond occurs. Weak inter­molecular N—H⋯S, C—H⋯O and C—H⋯π inter­actions are observed in the crystal structure.

The asymmetric unit of the title compound, C 21 H 25 N 3 O 2 SÁ0.5C 2 H 3 N, contains two independent molecules with almost similar structural properties along with a solvent molecule of acetonitrile. The compound exists in the E conformation with respect to the azomethine C N double bond. The hydrazinecarbothioamide moieties in both independent molecules are almost planar [maximum deviations of 0.013 (2) and 0.007 (2) Å ]. The molecular conformation is stabilized in each case by an intramolecular N-HÁ Á ÁN hydrogen bond. In the crystal, pairs of N-HÁ Á ÁS hydrogen bonds link each of the independent molecules into inversion dimers. The dimers are interconnected by means of three C-HÁ Á Á interactions.Keywords: crystal structure; hydrazinecarbothioamide; hydrogen bonding; C-HÁ Á Á interactions; antimicrobial applications.