(2E)-2-[1-(2-Hy-droxy-4-meth-oxy-phenyl)ethyl-idene]-N-phenyl-hydrazine-carbox-amide monohydrate.

The title compound, C(16)H(17)N(3)O(3)·H(2)O, exists in the E conformation with respect to the azomethine C=N double bond. While the phenyl ring is almost coplanar with the central hydrazinecarboxamide group [dihedral angle = 14.18 (11)°], it is twisted slightly with respect to the other aromatic ring in the mol-ecule, with a dihedral angle of 22.88 (13)°. The packing is dominated by O-H⋯O, N-H⋯O and C-H⋯O hydrogen-bond inter-actions, forming a three-dimensional supra-molecular structure which is augmented by two types of C-H⋯π inter-actions. An intramolecular O-H⋯N interaction is also present in the molecule.

Di-µ-acetato-κ(4)O:O-bis-({N'-[(E)-phen-yl-(pyridin-2-yl-κN)methyl-idene]benzo-hydrazidato-κ(2)N',O}copper(II)).

The binuclear molecule of the title compound, [Cu(2)(C(19)H(14)N(3)O)(2)(CH(3)COO)(2)], resides on a crystallographic inversion centre. It has an E conformation with respect to the azomethine double bond and a Z conformation about the amide C=N bond. The Cu(II) atom has a slightly distorted square-pyramidal coordination geometry. The crystal packing involves inter-molecular C-H⋯O, C-H⋯N and C-H⋯π and two types of π-π inter-actions, with centroid-centroid distances of 3.9958 (10) and 3.7016 (13) Å.

(Anilino{(Z)-2-[(E)-5-bromo-3-meth-oxy-2-oxidobenzyl-idene]hydrazin-1-yl-idene-κ(2)O(2),N(2)}methane-thiol-ato-κS)(4,4'-di-methyl-2,2'-bipyridine-κ(2)N,N')zinc N,N-dimethyl-formamide monosolvate.

The asymmetric unit of the title compound, [Zn(C(15)H(12)BrN(3)O(2)S)(C(12)H(12)N(2))]·C(3)H(7)NO, contains two independent mol-ecules with a similar structure. The doubly deprotonated Schiff base ligand O,N,S-chelates to the metal atom, and the three coordinating atoms along with one N atom of the substituted 2,2'-bipyridine ligand constitute the square plane of the distorted square pyramid surrounding the metal atom. The apical site is occupied by the second N atom of the substituted 2,2'-bipyridine. The secondary amine group of the Schiff base dianion forms a hydrogen bond to the O atom of the dimethyl-formamide solvent. In the crystal, the phenyl ring of one of the two Schiff base anions is disordered over two positions in a 1:1 ratio. The crystal studied is a racemic twin.

2-Eth-oxy-6-({2-[(3-eth-oxy-2-hy-droxy-benzyl-idene)amino]-benz-yl}imino-meth-yl)phenol.

The title compound, C(25)H(26)N(2)O(4), exists in an E conformation with respect to each azomethine link. The two phenol-substituted benzene rings are twisted away from the plane of the diimine benzene ring by dihedral angles of 27.25 (5) and 56.67 (5)°. The mol-ecular structure is stabilized by intra-molecular O-H⋯N hydrogen bonds.

Bis(1-phenyl-3-{(Z)-[phen-yl(pyridin-2-yl)methyl-idene]amino-κ²N,N'}urea-κO)nickel(II) dinitrate.

The Ni(II) atom in the title salt, [Ni(C19H16N4O)2](NO3)2, is N,N',O-chelated by two neutral Schiff base ligands in a distorted octa-hedral geometry. One nitrate ion inter-acts with the metal atom indirectly, in an outer-sphere type of coordination, through N-H⋯O hydrogen bonds; the other nitrate ion does not engage in any inter-actions and is equally disordered over two positions in the crystal.

(2E)-2-(5-Bromo-2-hy-droxy-3-meth-oxy-benzyl-idene)-N-phenyl-hydrazine-carbo-thio-amide.

The title compound, C(15)H(14)BrN(3)O(2)S, adopts an E,E conformation with respect to the azomethine and hydrazinic bonds and exists in the thio-amide form. The two rings in the mol-ecule are twisted away from each other, making a dihedral angle of 69.13 (13)°. In the crystal, mol-ecules are linked through pairs of N-H⋯O and O-H⋯S hydrogen bonds, leading to the formation of inversion dimers which are stacked along the a axis. Intra-molecular N-H⋯N, O-H⋯O and C-H⋯π inter-actions are also present.

(2E)-2-[(2-Hy-droxy-4-meth-oxy-phen-yl)(phen-yl)methyl-idene]-N-phenyl-hydrazinecarboxamide dimethyl-formamide monosolvate.

The title compound, C(21)H(19)N(3)O(3)·C(3)H(7)NO, adopts an E conformation with respect to the azomethine bond and crystallizes in the amide form. The dihedral angle between the rings lined to the C=N bond is 88.60 (12)°. The dimethyl-formamide solvent mol-ecule is disordered over two orientations with site occupancies of 0.684 (3) and 0.316 (3). The two N atoms of the hydrazinecarboxamide group are involved in inter-molecular N-H⋯O hydrogen bonds in which the dimethyl-formamide O atom acts as acceptor. The structure also features π-π inter-actions, with a centroid-centroid distance of 3.6561 (13) Å. Classical and non-classical intra-molecular O-H⋯N and C-H⋯O hydrogen bonds are also present.

(2E)-2-(5-Bromo-2-hy-droxy-3-meth-oxy-benzyl-idene)-N-cyclo-hexyl-hydrazine-carbothio-amide.

The title compound, C(15)H(20)BrN(3)O(2)S, crystallizes in the thio-amide form and adopts an E,E conformation with respect to the azomethine and hydrazinic bonds, respectively. The mol-ecules are paired through N-H⋯O and O-H⋯S hydrogen bonds, leading to the formation of centrosymmetric dimers in the crystal. These dimers are stacked along the a axis and are inter-connected through N-H⋯S hydrogen bonds to generate polymeric chains. The structure also features C-H⋯π interactions. An intra-molecular O-H⋯O bond is also present.