Synthesis, Crystal Structures and Antibacterial Activities of N,N'-Ethylene-bis(3-bromosalicylaldimine) and Its Copper(II) and Cobalt(III) Complexes.

A bis-Schiff base N,N'-ethylene-bis(3-bromosalicylaldimine) (H2L) was prepared from 3-bromosalicylaldehyde and ethane-1,2-diamine. With H2L as ligand, a new copper(II) complex [CuL] (1) and a new cobalt(III) complex [CoL(NCS)(DMF)] (2) were prepared and characterized by physico-chemical methods and single crystal X-ray analysis. X-ray analysis indicates that the Cu atom in complex 1 is in square planar coordination, and the Co atom in complex 2 is in octahedral coordination. The compounds were tested in vitro for their antibacterial activities on Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens. Both complexes have effective activities on the bacteria.

Two Zinc(II) Complexes with Similar Hydrazone Ligands: Syntheses, Crystal Structures and Antibacterial Activities.

A pair of new mononuclear zinc(II) complexes with hydrazone ligands 4-methoxybenzoic acid (1-pyridin-2-ylmethylidene)hydrazide (HLa) and benzoic acid (1-pyridin-2-ylethylidene)hydrazide (HLb) were prepared. They are [Zn(La)2] (1) and [Zn(Lb)2] (2). The complexes were characterized by physico-chemical methods and single crystal X-ray determination. The tridentate hydrazone ligands coordinate to the Zn atoms through the pyridine nitrogen, imino nitrogen and enolate oxygen atoms. The Zn atom in each complex is six coordinated by two hydrazone ligands, to form octahedral coordination. The complexes have effective activities against the bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens.

Synthesis and Crystal Structure of a Polymeric Copper(II) Complex Derived from 2-Hydroxy-5-methylbenzaldehyde Oxime with Antibacterial Activities.

A centrosymmetric O-bridged polynuclear copper(II) complex, [CuL2]n, where L is the deprotonated form of the Schiff base ligand 2-hydroxy-5-methylbenzaldehyde oxime, has been prepared and characterized by IR, UV and single-crystal X-ray determination. There is a crystallographic inversion center in the complex. The Cu atom in the complex is coordinated by the phenolate oxygen, imino nitrogen and hydroxyl oxygen atoms from two Schiff base ligands, forming octahedral geometry. The complex was tested in vitro for its antibacterial activity.

Synthesis, Crystal Structures and Antibacterial Activities of Trifluoromethylsulfonate Salts of 2-[(3-Chloropyridinium-2-yl)hydrazonomethyl]-6-methoxyphenol and its Copper(II) and Cobalt(III) Complexes.

A new trifluoromethylsulfonate salt of 2-[(3-chloropyridinium-2-yl)hydrazonomethyl]-6-methoxyphenol, (HL)CF3SO3, and its copper(II) and cobalt(III) complexes, [CuL(OH2)]CF3SO3 · 0.5H2O (1) and [CoL2]CF3SO3 · CH3OH (2), were prepared and characterized by physico-chemical methods and single crystal X-ray analysis. A trifluoromethylsulfonate anion is present in each of the compounds. The Cu atom in complex 1 is coordinated by the phenolate O, imino N and pyridine N atoms of L ligand, giving square planar geometry. The Co atom in complex 2 is coordinated by two phenolate O, two imino N and two pyridine N atoms from two L ligands, giving octahedral geometry. The three compounds were tested in vitro for their antibacterial activities.

N'-(3,5-Dibromo-2-hydroxy-benzyl-idene)-3,4-methyl-enedioxy-benzohydrazide.

In the asymmetric unit of the title hydrazone compound, C(15)H(10)Br(2)N(2)O(4), there are two independent mol-ecules. In each mol-ecule, the five-membered ring adopts a flattened envelope conformation; the flap atoms are displaced by 0.114 (2) and 0.219 (2) Šfrom the planes of the other four atoms. In one mol-ecule the dihedral angle between the two benzene rings is 22.8 (2)°, while in the other it is 40.8 (2)°. Each mol-ecule displays an E configuration with respect to the C=N bond. In both mol-ecules, intra-molecular O-H⋯N hydrogen bonds are observed. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains along the a axis.

N'-(5-Bromo-2-methoxy-benzyl-idene)-3,4-methyl-enedioxy-benzohydrazide.

In the title mol-ecule, C(16)H(13)BrN(2)O(4), the two benzene rings form a dihedral angle of 74.9 (2)°. In the crystal, mol-ecules are linked via inter-molecular N-H⋯O hydrogen bonds into chains propagating along the c axis.

N'-(5-Bromo-2-methoxy-benzyl-idene)-2-methoxy-benzohydrazide.

The title hydrazone compound, C(16)H(15)BrN(2)O(3), adopts an E configuration about the C=N double bond. The mol-ecule is twisted, the dihedral angle between the two substituted benzene rings being 22.0 (2)°. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains along the c axis.

N'-(5-Bromo-2-methoxy-benzyl-idene)-4-hydroxy-benzohydrazide methanol solvate.

In the title hydrazone compound, C(15)H(13)BrN(2)O(3)·CH(3)OH, the methanol solvate is linked to the benzohydrazide molecule through O-H⋯N and O-H⋯O hydrogen bonds. The benzohydrazide mol-ecule adopts an E configuration about the C=N double bond. The mol-ecule is twisted, with a dihedral angle between the two substituted benzene rings of 35.7 (2)°. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O and O-H⋯O hydrogen bonds, forming layers parallel to the ac plane.