Synthesis and structure of 2-acetylpyridine-salicyloylhydrazone and its copper(ii) and zinc(ii) complexes. The effect of the metal coordination on the weak intermolecular interactions

Synthesis and characterization of several rhenium(I) complexes of 2-acetylpyridine and ferrocenyl carbaldehyde derivatives of 2-hydroxybenzoic acid hydrazide

“…doi:10.1016/j.jorganchem.2009.05.032 the phenolic hydroxy, amide oxygen and one/two imine nitrogen atoms. However, in the copper(II) and zinc(II) complexes of the pyridine derivatives reported, we observed exclusively the tridentate monodeprotonated ligand [H(py)L 2 ] À [16]. The structural data for H 2 (Fc)L 2 are even more scarce, although the presence of a bidentate neutral ligand has been reported in a ruthenium(II) complex [17].…”

“…The differences between these angles are statistically insignificant apart from the expected longer Re-Br distance than Re-Cl and the N(2)@C(8) distance in 1a being clearly shorter than in 1b. The latter distance in 1a is statistically equivalent to that observed in the free ligand [1.285(4) Å] [16] and in its hydrochloride form [1.288(2) Å] [20] while that in 1b is similar to that found in the ferrocene derivatives 2 (vide infra).…”

“…Other interesting differences with respect to the free ligand structure are the change in the orientation of the pyridine nitrogen atom to allow N,N 0 coordination to the rhenium and the loss of the planarity observed in the free form [16] by rotation around the N(1)-N(2) bond. Consequently, the angle between the planes defined by the salicylaldehyde and pyridine groups (see Scheme 3) is greater than 60°.…”

Crystal Structures and Antimicrobial Activities of N'-[2,5-Dihydroxybenzylidene]-3,4,5-Trimethoxybenzohydrazide, N'-[2,4-Dichlorobenzylidene]-3,4,5-Trimethoxybenzohydrazide, and 2,4-Dichloro-N'-(2-Hydroxy-3-Methoxy-5-Nitrobenzylidene)benzohydrazide Ethanol Solvate

“…The benzohydrazone molecules in the compounds have E configurations with respect to the C=N double bonds and C-N single bonds. In each compound, the benzohydrazone molecule is twisted, with the dihedral angle between the two benzene rings of 28.5(3)° for (1), 40.9(3)° for (2), and 48.8(3)° for (3). All the bond lengths in the compounds are within normal ranges, 16 and comparable to each other.…”

“…[1][2][3] The chemistry of these compounds has been intensively investigated in recent years. The reasons are manifold: the versatile biological activities, such as antibacterial and antitubercular, [4][5][6] the coordination abilities to most metal ions, 7,8 and promising properties for analytical applications.…”