Synthesis, spectroscopic characterization and crystal structure of mixed ligand Ni(II) complex of N-4-diethylaminosalicylidine-N′-4-nitrobenzoyl hydrazone and 4-picoline

Crystal structure of N'-[(E)-3,5-di-chloro-2-hy-droxy-benzyl-idene]-4-nitro-benzo-hydrazide di-methyl-formamide monosolvate

In the title compound, C14H9Cl2N3O4·C3H7NO, the hydrazone mol-ecule 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 mol-ecule is stabilized by the intra-molecular 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 di-methyl-formamide solvent mol-ecule 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 mol-ecules into chains along [322]. A supra-molecular 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] inter-actions.

N′-[(E)-4-(Diethylamino)benzylidene]-4-nitrobenzohydrazide monohydrate

In the title compound, C₁₈H₂₀N₄O₃·H₂O, the two aromatic rings are linked through a methyl­idenehydrazide fragment, which is fully extended with C—C—N—N, C—N—N=C and N—N=C—C torsion angles of 179.4 (2), 174.7 (2) and 178.3 (2)°, respectively. The dihedral angle between the two aromatic rings is 7.01 (8)°. In the crystal structure, the water of hydration is involved in extensive hydrogen bonding. Inter­molecular O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonds link the components of the structure into a two-dimensional network and additional stabilization is provided by weak inter­molecular C—H⋯O hydrogen bonds.

Synthesis, spectral characterization and crystal structure of N-2-hydroxy-4-methoxybenzaldehyde-N'-4-nitrobenzoyl hydrazone and its square planar Cu(II) complex

A new aroyl hydrazone, N-2-hydroxy-4-methoxybenzaldehyde-N'-4-nitrobenzoyl hydrazone (H2L) and its mixed ligand Cu(II) complex [CuLpy] [py, pyridine] have been prepared. The ligand is characterized by elemental analysis, electronic, infrared and NMR spectral studies and the complex by electronic, infrared, EPR spectral studies and the magnetic susceptibility data. The structures of the compounds were determined by single crystal X-ray diffraction studies. Both the ligand and the Cu complex crystallize into a triclinic lattice with a space group of PI. From the crystal studies, it is concluded that the ligand molecule exits in the keto form in the solid state, while at the time of complexation, it tautomerises into the enol form. The complex is formed by the double deprotonation of the ligand molecule--both the phenolic and the enolic protons.