The asymmetric unit of the title compound, [Mo(C19H16Br4N2O2)O2], comprises two mol­ecules. The coordination environments around the MoVI atoms are distorted octa­hedral, defined by two oxide ligands and an N2O2 donor set of the tetra­dentate Schiff base in each mol­ecule. The dihedral angles between the benzene rings in the mol­ecules are 76.2 (3) and 77.7 (3)°. An inter­esting feature of the crystal structure is the presence of Br⋯Br contacts [3.4407 (11), 3.5430 (11) and 3.6492 (10) Å], which are shorter than the sum of the van der Waals radius of Br atoms (3.70 Å). The crystal structure is further stabilized by inter­molcular C—H⋯Br and C—H⋯π inter­actions. The crystal under investigation was twinned by nonmerohedry in a 0.053 (1):0.947 (1) ratio.

The asymmetric unit of the title compound, [Cu(C21H24N2O4)]·H2O, comprises half of a Schiff base complex and a water mol­ecule. The CuII atom, water mol­ecule and one C atom of the central propyl­ene segment are located on a twofold rotation axis. The geometry around the CuII atom is distorted square-planar, supported by the N2O2 donor atoms of the coordinating ligand. The dihedral angle between the symmetry-related benzene rings is 42.56 (19)°. In the crystal, O—H⋯O hydrogen bonds involving the water mol­ecule make an R 2 1(6) ring motif. Complex mol­ecules are linked into a chain along the c axis via C—H⋯O inter­actions.

The asymmetric unit of the title compound, [Mo(C19H16Cl4N2O2)O2], comprises two independent mol­ecules (A and B). The geometry around the MoVI atom is distorted octa­hedral in each complex mol­ecule, supported by two oxide O atoms and the N2O2 donor atoms of the coordinating ligand. The dihedral angle between the benzene rings is 74.96 (11) Å for mol­ecule A and 76.05 (11) Å for mol­ecule B. In the crystal, the B mol­ecules are linked by pairs of C—H⋯Cl hydrogen bonds, forming inversion dimers. The crystal structure is further stabilized by C—H⋯π inter­actions. An inter­esting feature of the crystal structure is a Cl⋯Cl contact [3.3748 (18) Å], which is shorter than the sum of the van der Waals radii of Cl atoms (3.50 Å).

The asymmetric unit of the title compound, [Cu(C21H24N2O2)]·H2O, comprises half of a Schiff base complex and half of a water mol­ecule. The whole compound is generated by crystallographic twofold rotation symmetry. The geometry around the CuII atom, located on a twofold axis, is distorted square-planar, which is supported by the N2O2 donor atoms of the coordinating Schiff base ligand. The dihedral angle between the symmetry-related benzene rings is 47.5 (4)°. In the crystal, the water mol­ecule that is hydrogen bonded to the coordinated O atoms links the mol­ecules via O—H⋯O inter­actions into chains parallel to [001]. The crystal structure is further stabilized by C—H⋯π inter­actions, and by π–π inter­actions involving inversion-related chelate rings [centroid–centroid distance = 3.480 (4) Å].

In the title mol­ecule, C15H13NO2S, an intra­molecular O—H⋯N hydrogen bond forms an S(6) ring motif. The benzothia­zole ring system and the benzene ring form a dihedral angle of 8.9 (3) Å. In the crystal, mol­ecules are linked by weak C—H⋯O hydrogen bonds, forming chains along the b axis. In addition, π–π inter­actions [centroid–centroid distances = 3.772 (4) and 3.879 (4) Å] are observed.

The asymmetric unit of the title compound, C28H22Br2N2O2S2, comprises half of a Schiff base ligand, the whole mol­ecule being generated by a crystallographic inversion center located at the mid-point of the C—C bond of the central methyl­ene segment. Intra­molecular O—H⋯N and O—H⋯S hydrogen bonds make S(6) and S(5) ring motifs, respectively. In the crystal, there are no significant inter­molecular inter­actions.

In the title Schiff base complex, [Cu(C19H18Cl2N2O2)], the CuII ion is coordinated in a distorted square-planar environment by two N atoms and two O atoms of the tetra­dentate ligand. The dihedral angle between the benzene rings is 36.86 (14)°. In the crystal, mol­ecules are linked into inversion dimers by pairs of weak C—H⋯O hydrogen bonds. In addition, π–π [centroid–centroid distance = 3.7279 (16) Å] and weak C—H⋯π inter­actions are observed.

The asymmetric unit of the title compound, [Ni(C17H12I4N2O2)], comprises half of a Schiff base complex. The NiII and central C atom of the propyl chain are located on a twofold rotation axis. The geometry around the NiII atom is square planar, supported by the N2O2 donor atoms of the coordinated ligand. In the crystal, there are no significant inter­molecular inter­actions present. The crystal studied was a non-merohedral twin with a refined twin component ratio of 0.944 (1):0.056 (1).

In the title compound, C17H14I4N2O2, there are two intra­molecular O—H⋯N hydrogen bonds, which make S(6) ring motifs. In the crystal, there are no significant inter­molecular inter­actions present.

The asymmetric unit of the title compound, C16H12Br4N2O2, comprises half of a potential tetra­dentate Schiff base ligand. The whole mol­ecule is generated by an inversion center located in the middle of the C—C bond of the ethyl­ene segment. There are intra­molecular O—H⋯N hydrogen bonds making S(6) ring motifs. In the crystal, no significant inter­molecular inter­actions are observed.

In the title compound, C15H15N3O3·H2O, the hydazide Schiff base mol­ecule shows an E conformation around the C=N bond. An intra­molecular O—H⋯N hydrogen bond makes an S(6) ring motif. The dihedral angle between the substituted phenyl rings is 23.40 (11)°. The water mol­ecule mediates linking of neighbouring mol­ecules through O—H⋯(O,O) hydrogen bonds into infinite chains along the a axis, which are further connected together through N—H⋯O hydrogen bonds, forming a two-dimensional network parallel to (001). C—H⋯O inter­actions aso occur.

The title compound, C17H14Cl4N2O2, is generated by crystallographic twofold symmetry. The two benzene rings are inclined to one another by 80.17 (10)°. There are two intra­molecular O—H⋯N hydrogen bonds, which make S(6) ring motifs. In the crystal, mol­ecules are linked by C—H⋯O and weak C—H⋯Cl inter­actions, forming a three-dimensional network.

The asymmetric unit of the title compound, C16H12Cl4N2O2, comprises half of a potentially tetra­dentate Schiff base ligand, located about a twofold rotation axis which bis­ects the central C—C bond of the ethane-1,2-diamine group. In the solid state, the compound exists in the zwitterionic form. There are two intra­molecular N—H⋯O hydrogen bonds making S(6) ring motifs. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming two-dimensional frameworks which lie parallel to (100). There are also short Cl⋯Cl [3.4395 (9) Å] contacts present.

The asymmetric unit of the title compound, C18H16Cl4N2O2, comprises half of a potentially tetra­dentate Schiff base ligand. It is located about a twofold rotation axis that bis­ects the central C—C bond of the butane-1,4-diamine group. There are two intra­molecular O—H⋯N hydrogen bonds making S(6) ring motifs. In the crystal, mol­ecules are linked by pairs of weak C—H⋯Cl inter­actions, forming inversion dimers, which are further connected by C—H⋯O hydrogen bonds into two-dimensional frameworks that lie parallel to (001).

The asymmetric unit of the title compound, C18H16Br4N2O2, comprises half the molecule, which is located adjacent to an inversion centre at the mid-point of the central C—C bond of the butane-1,4-diamine segment. There are two intra­molecular O—H⋯N hydrogen bonds making S(6) ring motifs. In the crystal, mol­ecules are linked by pairs of weak C—H⋯Br inter­actions into chains along [101], which include R 2 2(8) ring motifs. These chains are further linked by C—H⋯O hydrogen bonds, forming a three-dimensional network.

In the title Schiff base complex, [Ni(C18H14Cl4N2O2)(C3H7NO)2], the geometry around the NiII atom is distorted octa­hedral. It is coordinated by the N2O2 donor atoms of the tetra­dentate Schiff base ligand and the O atoms of two dimethyl­formamide mol­ecules, which are cis to one another. The benzene rings are almost normal to each other [dihedral angle = 88.60 (14)°]. The various intra­molecular C—H⋯O hydrogen bonds make S(5) and S(6) ring motifs. In the crystal, mol­ecules are linked by pairs of weak C—H⋯Cl inter­actions, forming inversion dimers.

The asymmetric unit of the title compound, [Cu2(C18H14Cl4N2O2)2]n, contains two independent CuII ions which are bridged by a pair of 4,4′,6,6′-tetra­chloro-2,2′-[butane-1,4-diylbis(nitrilo­methanylyl­idene)]diphenolate ligands, forming a dinuclear unit. One of the CuII ions is coordinated in a distorted square-planar environment and the other is coordinated in a distorted square-pyramidal environment. The long apical Cu—O bond of the square-pyramidal coordinated CuII ion is formed by a symmetry-related O atom, creating a one-dimensional polymer along [010]. In addition, short inter­molecular Cl⋯Cl distances [3.444 (2) Å] and weak π–π inter­actions [centroid–centroid distances = 3.736 (2)–3.875 (3) Å] are observed. The crystal studied was an inversion twin with a refined twin component ratio of 0.60 (1):0.40 (1).

The asymmetric unit of the title coordination polymer consists of a dinuclear neutral complex mol­ecule of formula [Cu2(C18H14Br4N2O2)2]n. One of the CuII ions is coordinated in a distorted square-planar geometry, whereas the other is coordinated in a distorted square-pyramidal geometry, the long apical Cu—O bond [2.885 (4) Å] of the square-pyramidal coordination being provided by a symmetry-related O atom creating a one-dimensional polymer along [010]. π–π stacking inter­actions [centroid–centroid distance = 3.783 (4) Å] and short inter­chain Br⋯Br inter­actions [3.6142 (12)–3.6797 (12) Å] are observed.

The asymmetric unit of the title compound, C15H15N3O2, comprises two crystallographically independent mol­ecules (A and B), each having an E conformation around the C=N bond. In each mol­ecule, there is an intra­molecular O—H⋯N hydrogen bond making an S(6) ring motif. The dihedral angles between the substituted phenyl rings are 17.49 (9) and 10.03 (9)°. In the crystal, N—H⋯O hydrogen bonds link neighbouring independent mol­ecules into infinite chains, of the type –A–B–A–B–, along the a axis, enclosing R 2 1(7) ring motifs. The chains are linked by N—H⋯O hydrogen bonds and C—H⋯O inter­actions, leading to the formation of a three-dimensional network.

The asymmetric unit of the title compound, C7H9N3O2, comprises two crystallographically independent mol­ecules (A and B). In each mol­ecule there is an intra­molecular O—H⋯O hydrogen bond making an S(6) ring motif. In the crystal, a pair of N—H⋯N hydrogen bonds link the two mol­ecules (A and B) into a dimer with an R 2 2(6) ring motif. The B mol­ecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R 2 2(10) ring motif. The mol­ecules are further linked via other N—H⋯O hydrogen bonds, forming undulating two-dimensional networks lying parallel to the bc plane. These networks are finally linked via N—H⋯O hydrogen bonds, forming a three-dimensional structure.

In the title hydrazide Schiff base compound, C14H12ClN3O2, the conformation around the C=N double bond is E. The dihedral angle between the benzene rings is 41.57 (14) Å. An intra­molecular O—H⋯N hydrogen bond makes an S(6) ring motif. In the crystal, mol­ecules are linked by N—H⋯O (bifurcated acceptor) and N—H⋯N hydrogen bonds, forming chains along the a axis. The inter­esting feature of the crystal structure is the short inter­molecular C⋯O [3.216 (3), 3.170 (3), and 2.992 (3) Å] contacts, one of which is significantly shorter than the sum of the van der Waals radii of these atoms [3.22 Å].

In t the title compound, C14H12BrN3O2. H2O, the conformation of the C=N double bond in the hydrazide Schiff base mol­ecule is E. The dihedral angle between the benzene rings is 48.01 (11) °. An intra­molecular O—H⋯N hydrogen bond makes an S(6) ring motif. In the crystal, mol­ecules are linked through N—H⋯O (bifurcated acceptor) and O—H⋯O hydrogen bonds, forming two-dimensional networks lying parallel to (100).

The asymmetric unit of the title compound, [Ni(C19H16I4N2O2)], comprises half of a Schiff base complex. The NiII atom is located on a twofold rotation axis which also bis­ects the central C atom of the 2,2-dimethyl­propane group of the ligand. The geometry around the NiII atom is distorted square-planar, with a dihedral angle of 21.7 (3)° between the symmetry-related N/Ni/O coordination planes. The dihedral angle between the symmetry-related benzene rings is 27.9 (3)°. In the crystal, short inter­molecular I⋯I [3.8178 (9) and 3.9013 (10) Å] inter­actions are present.

The asymmetric unit of the title compound, [Zn(C19H16Cl4N2O2)(H2O)], comprises two crystallographically independent mol­ecules. The geometry around the ZnII atoms is distorted trigonal–bipyramidal, supported by the N2O2 donor atoms of the tetradentate Schiff base and a coordinating water mol­ecule. The dihedral angles between the benzene rings in the two mol­ecules are 34.10 (15) Å and 30.61 (15) Å. In the crystal, neighbouring independent mol­ecules are linked by pairs of O—H⋯O hydrogen bonds, forming dimers with R 2 2(6) ring motifs, and by O—H⋯Cl hydrogen bonds. There are short Cl⋯Cl [3.4728 (16), 3.4863 (16), and 3.388 (1) Å] contacts present, and mol­ecules are also linked by C—H⋯O and π–π [centroid–centroid distance = 3.671 (2) Å] inter­actions.

In the title compound, [Cu(C19H16I4N2O2)], the CuII atom and the substituted C atom of the diamine segment lie on a crystallographic twofold rotation axis. The geometry around the CuII atom is distorted square-planar, which is supported by the N2O2 donor atoms of the coordinated Schiff base. The dihedral angle between the symmetry-related substituted benzene rings is 29.40 (19)°. In the crystal, a short I⋯I [3.8766 (6) Å] contact is present and links neighbouring mol­ecules into chains propagating along the a axis.