Synthesis, spectral characterization, in-vitro microbiological evaluation and cytotoxic activities of novel macrocyclic bis hydrazone

A macrocyclic hydrazone Schiff base was synthesized by reacting 1,4-dicarbonyl phenyl dihydrazide with 2,6-diformyl-4-methyl phenol and a series of metal complexes with this new Schiff base were synthesized by reaction with Co(II), Ni(II) and Cu(II) metal salts. The Schiff base and its complexes have been characterized by elemental analyses, IR, 1H NMR, UV-vis, FAB mass, ESR spectra, fluorescence, thermal, magnetic and molar conductance data. The analytical data reveal that the Co(II), Ni(II) and Cu(II) complexes possess 2:1 metal-ligand ratios. All the complexes are non-electrolytes in DMF and DMSO due to their low molar conductance values. Infrared spectral data suggest that the hydrazone Schiff base behaves as a hexadentate ligand with NON NON donor sequence towards the metal ions. The ESR spectral data shows that the metal-ligand bond has considerable covalent character. The electrochemical behavior of the copper(II) complex was investigated by cyclic voltammetry. The Schiff base and its complexes have also been screened for their antibacterial (Escherichia coli, Staphylococcus aureus, Shigella dysentery, Micrococcus, Bacillus subtilis, Bacillus cereus and Pseudomonas aeruginosa) and antifungal activities (Aspergillus niger, Penicillium and Candida albicans) by MIC method. The brine shrimp bioassay was also carried out to study their in-vitro cytotoxic properties. © 2009 Elsevier Masson SAS. All rights reserved

Synthesis and characterization of Schiff base metal complexes and reactivity studies with maleimide epoxy resin

A novel maleimide epoxy contg. Co(II)​, Ni(II)​, and Cu(II) ions have been synthesized by curing a maleimide epoxy resin (MIEB-​13) with Co(II)​, Ni(II)​, and Cu(II) complexes of a macrocyclic bis-​hydrazone Schiff base. The Schiff base was synthesized by reacting terephthaloyl dihydrazide with 2,​6-​diformyl-​4-​methylphenol. The Schiff base and its Co(II)​, Ni(II)​, and Cu(II) complexes have been characterized by elemental analyses, spectral (IR, 1H NMR, UV-​vis., FAB mass, ESR)​, thermal, and magnetic data. The curing reaction of the epoxy resin was carried out with the metal complex crosslinking agents. The stability of the cured samples was studied by thermogravimetric analyses; the products have excellent chem. (acid​/alkali​/solvent) and water absorption resistance. Further, SEM and DSC techniques confirmed the phase homogeneity of the cured systems

3-Chloro-N′-(2-chloro-5-nitro­benzyl­idene)­benzohydrazide

The title mol­ecule, C14H9Cl2N3O3, has an E configuration with respect to the methyl­idene unit. The dihedral angle between the mean planes of the two benzene rings is 12.3 (3)°. In the crystal, mol­ecules are linked via bifurcated N—H⋯(O, N) hydrogen bonds into chains along [001]

Synthesis, spectral characterization and in vitro microbiological evaluation of novel glyoxal, biacetyl and benzil bis-hydrazone macrocyclic Schiff bases and their Co(II), Ni(II) and Cu(II) complexes

A series of binuclear Co(II), Ni(II) and Cu(II) complexes were synthesized by the template condensation of glyoxal, biacetyl or benzil bis-hydrazide, 2,6-diformyl-4-methylphenol and Co(II), Ni(II) or Cu(II) chloride in a 2:2:2 M ratio in ethanol. These 22-membered macrocyclic complexes were characterized by elemental analyses, magnetic, molar conductance, spectral, thermal and fluorescence studies. Elemental analyses suggest the complexes have a 2:1 stoichiometry of the type M2LX2·nH2O and Ni2LX22H2O·nH2O (where M = Co(II) and Cu(II); L = H2L1, H2L 2 and H2L3; X = Cl; n = 2). From the spectroscopic and magnetic studies, it has been concluded that the Co(II) and Cu(II) complexes display a five coordinated square pyramidal geometry and the Ni(II) complexes have a six coordinated octahedral geometry. The Schiff bases and their metal complexes have also been screened for their antibacterial and antifungal activities by the MIC method. © 2011 Elsevier Ltd. All rights reserved

N′-(3,5-Dichloro-2-hy­droxy­benzyl­idene)-4-nitro­benzohydrazide methanol solvate

In the title compound, C14H9Cl2N3O4·CH4O, the dihedral angle between the two benzene rings in the hydrazone mol­ecule is 6.3 (3)°. An intra­molecular N—H⋯O hydrogen bond stabilizes the mol­ecular conformation. In the crystal, centrosymmetrically related mol­ecules are linked through inter­molecular O—H⋯O and N—H⋯O hydrogen bonds

N′-(2-Meth­oxy­benzyl­idene)-4-nitro­benzohydrazide

The mol­ecule of the title compound, C15H13N3O4, adopts an E configuration with respect to the C=N bond. The dihedral angle between the two benzene rings is 6.0 (3)°. In the crystal, mol­ecules are linked through inter­molecular N—H⋯O hydrogen bonds to form chains along the c axis

N′-(4-Chloro­benzyl­idene)-2-[4-(methyl­sulfan­yl)phen­yl]acetohydrazide

In the title compound, C16H15ClN2OS, the hydrazine group is twisted slightly: the C—N—N—C torsion angle is 175.46 (13)°. The dihedral angle between the two terminal aromatic rings is 87.01 (8)°. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R 2 2(8) loops. The dimers are further linked by weak C—H⋯π inter­actions

N′-(4-Fluoro­benzyl­idene)-2-(4-fluoro­phen­yl)acetohydrazide

In the title compound, C15H12F2N2O, the dihedral angle between the two benzene rings is 48.73 (8)°. The hydrazine group is twisted slightly, with a C—N—N—C torsion angle of 172.48 (12)°. In the crystal, mol­ecules are connected by strong N—H⋯O and weak C—H⋯O hydrogen bonds, forming supra­molecular chains along the c axis. The structure is consolidated by π–π [centroid–centroid separation = 3.6579 (10) Å] and C—H⋯π inter­actions

10,21-Dimethyl-2,7,13,18-tetraphenyl-3,6,14,17-tetraazatricyclo[17.3.1.18,12]tetracosa-1(23),2,6,8(24),9,11,13,17,19,21-decaene-23,24-diol cyclohexane 0.33-solvate

The title compound, C46H40N4O2·0.33C6H12, was obtained unintentionally as a product of an attempted synthesis of a cadmium(II) complex of the [2,6-{PhSe(CH2)2N=CPh}2C6H2(4-Me)(OH)] ligand. The full tetra­imino­diphenol macrocyclic ligand is generated by the application of an inversion centre. The macrocyclic ligand features strong intra­molecular O—H⋯N hydrogen bonds. The dihedral angles formed between the phenyl ring incorporated within the macrocycle and the peripheral phenyl rings are 82.99 (8) and 88.20 (8)°. The cyclo­hexane solvent mol­ecule lies about a site of symmetry. Other solvent within the lattice was disordered and was treated with the SQUEEZE routine [Spek (2009). Acta Cryst. D65, 148–155]