Bis(dimethylformamide-κO){4,4′,6,6′-tetrachloro-2, 2-[butane-1,4-diyl(nitrilomethanylylidene)]diphenolato-κ4O,N, N′,O′}nickel(II).

In the title Schiff base complex, [Ni(C18H14Cl 4N2O2)(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. © 2012 International Union of Crystallography

Aqua{4,4′,6,6′-tetra­chloro-2,2′-[(2,2-di­methylpropane-1,3-diyl)bis­(nitrilomethanylyl­idene)]diphenolato}zinc.

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 R22(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

The specificity of learned associations in visuomotor and perceptual processing

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 [pi]-[pi] 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)

(E)-4-Amino-N′-(2-hydroxy-5-methylbenzylidene)benzohydrazide

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 R21(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