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A new macrocyclic multidentate Schiff-base ligand Na4L consisting of two submacrocyclic units (10,21-bis-iminomethyl-3,6,14,17-tricyclo[17.3.1.1]tetracosa-1(23),2,6,8,10,12(24),13,17,19,21,-decaene-23,24-disodium) and its tetranuclear metal complexes with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) are reported. Na₄L was prepared via a template approach, which is based on the condensation reaction of sodium 2,4,6-triformyl phenolate with ethylenediamine in mole ratios of 2 : 3. The tetranuclear macrocyclic-based complexes were prepared from the reaction of the corresponding metal chloride with the ligand. The mode of bonding and overall geometry of the compounds were determined through physicochemical and spectroscopic methods. These studies revealed tetrahedral geometries about Mn, Co, and Zn atoms. However, square planar geometries have been suggested for Ni(II) and Cu(II) complexes. Biological activity of the ligand and its metal complexes against Gram positive bacterial strain Staphylococcus aureus and Gram negative bacteria Escherichia coli revealed that the metal complexes become more potentially resistive to the microbial activities as compared to the free ligand. However, these metal complexes do not exhibit any effects on the activity of Pseudomonas aeruginosa bacteria. There is therefore no inhibition zone.

The synthesis of a new mixed Schiff-base and DTCs ligands and its metal complexes are reported. Schiff-base was prepared by reaction of ((E)-2-amino-6-(pyridin-2-yl diazenyl)phenol) with 4-(dimethylamino)benzaldehyde). The complexes were prepared by mixing the (2-(((E)-4-(dimethylamino)benzylidene)amino)-6-((E)-pyridin-2-yldiazenyl)phenol) ligand (HL) and (potassium diphenylcarbamodithioate) ligand (L) with the metal salts; Cobalt(II), Nickel(II), Zinc(II) and Cadmium(II) in a 1:1:1 mole ratio. Physico-chemical techniques were implemented, as required, to characterise the ligands and complexes. These include; elemental microanalysis, Fourier Transform Infrared Spectra, Electronic spectra and 1H-Nuclear magnetic resonance spectroscopy, chloride content, magnetic susceptibility and conductance. Thermal stability (TGA-DSC) of the ligand and selected complexes were also investigated. These analyses revealed the isolation of six and four coordinate structures in the solid and solution sate. The antimicrobial activity of the ligand and its complexes against bacterial strains species was examined. [ABSTRACT FROM AUTHOR]

Synthesis and characterisation two Schiff bases ligands[L1] (N1Z, N3Z)-N1, N3-bis(4-((E)-anthracen-9-ylmethyleneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-ylidene)benzene-1,3-diamine Synthesis via reaction of m-phenylenediamine, 4-aminoantipyrine and 9-anthracenecarboxaldehyde with mole ratio (1:2:2) respectively two steps. And[L2] (N1Z, N2Z)-N1, N2-bis(4-((E)-anthracen-9-ylmethyleneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-ylidene)-4-methylbenzene-1,2-diamine Synthesis from reaction of 3,4diaminotoluene, 4-aminoantipyrine and 9-anthracenecarboxaldehyde with mole ratio (1:2:2)respectively two steps. A new series of transition metal complexes of Mn(II), Co(II), Ca(II), Cd(II), Zn(II) and pd(II) were synthesized. The structural features were derived from their elemental analyses, infrared, UV-visible spectroscopy, 1HNMR, 13CNMR spectroscopy, thermal gravimetric analyses spectral, magnetic susceptibility measurement, chloride content and conductivity measurements. The electronic spectral data and magnetic measurements indicate that the complexes exhibit octahedral geometry around Ca(II), Mn(II), Cd(II), Co(II), Zn(II) while Square planer geometry around Pd(II). [ABSTRACT FROM AUTHOR]

Synthesis and characterisation two Schiff bases[L1] (N2Z,N6Z)-N2,N6-bis(4-((E)-anthracen-9-ylmethyleneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-ylidene)pyridine-2,6-diamine Synthesis via reaction of 2,6-diaminopyridine, 4-aminoantipyrine and 9-anthracenecarboxaldehyde with mole ratio (1:2:2) respectively two steps. And[L2] (N1Z,N2Z)-N1,N2-bis(4-((E)-anthracen-9-ylmethyleneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-ylidene)-4-methylbenzene-1,2-diamine Synthesis from reaction of o-phenylendiamine,4-aminoantipyrine and 9-anthracenecarboxaldehyde with mole ratio (1:2:2)respectively two steps. A new series of transition metal complexes of Mn(II), Co(II), Ca(II), Cd(II), Zn(II) and pd(II) were synthesized. The structural features were derived from their elemental analyses, infrared, UV-visible spectroscopy, 1HNMR, 13CNMR spectroscopy, thermal gravimetric analyses spectral, magnetic susceptibility measurement, chloride content and conductivity measurements. The electronic spectral data and magnetic measurements indicate that the complexes exhibit octahedral geometry around Ca(II), Mn(II), Cd(II), Co(II), Zn(II) while Square planer geometry around Pd(II). [ABSTRACT FROM AUTHOR]

New Schiff-base ligands bearing tetrazole moiety and their polymeric metal complexes with Co(II), Ni(II) and Cd(II) ions are reported. Ligands were prepared in a multiple-step reaction. The reaction of sodium 2,6- diformylphenolate and cyclohexane-1,3-dione with 5-amino-2-fluorobenzonitrile resulted in the isolation of two precursors sodium 2,6-bis((E)-(3-cyano-4-fluorophenylimino)methyl)-4-methylphenolate 1 and 5,5'- (1E,1'E)-cyclohexane-1,3-diylidenebis- (azan-1-yl-1-ylidene)bis(2-fluorobenzonitrile) 2, respectively. The reaction of precursors with azide gave the required ligands; sodium 2,6-bis((E)-(4-fluoro-3-(1H-tetrazol-5- yl)phenylimino)methyl)-4-methylphenolate (NaL) and (N, N'E, N, N'E)-N, N'-(cyclohexane-1,3-diylidene)bis(4- fluoro-3-(1H-tetrazol-5-yl)aniline) (L1). The reaction of these ligands with the appropriate metal ions gave polymeric metal complexes of the formulae {[M2(L)]Cl}n and [M(L1)Cl2]n (where M = Co(II), Ni(II) and Cd(II)). A range of techniques were used to confirm the entity of ligands and their complexes. The formation of ligands and mode of complexation and geometrical structure of the title polymeric complexes were verified using FTIR, electronic spectra, NMR, ESMS, magnetic susceptibility, micro-elemental analysis, metal content, chloride content and conductance. The analytical and spectroscopic data indicated the formation of four-coordinate complexes, with a tetrahedral geometry for Co(II) and Cd(II), and square planer for Ni(II) in L- and L1 complexes. Biological evaluation of ligands and their polymeric complexes against gram-positive bacteria (G+), Bacillus stubtili, Staphylococcus aureus, and gram-negative bacteria (G-), Escherichia coli and Pseudomonas aeruginosa, showed ligands and their polymeric metal complexes have a good effect on the screened bacteria. [ABSTRACT FROM AUTHOR]

The study includes preparation and characterisation of mixed azo-linked Schiff-base ligands and their complexes. The starting material was isolated from the mixing of 2-amino pyridine diazonium salt with 2-amino-phenole and 4-amino-3-hydroxy-1-naphthalene sulfonic acid respectively in 1:1 mole ratio in water. In this work, the formation of azo-linked Schiffbase ligands are reported. Ligands of the azo-linked Schiff-base was achieved by the reaction of starting material with 4-(dimethylamino) benzaldehyde) (HL1 and HL2). The complexes were prepared by mixing the azo-linked Schiff-base ligands with the metal salts; CoII, NiII and CdII in a 1:1:1 mole ratio. Ligands and complexes were characterised by analytical and spectroscopic analyses including; microanalysis, chloride content, thermal analysis, magnetic susceptibility for complexes, conductance, FTIR, UV-Vis and 1H-NMR spectroscopy. Physico-chemical techniques indicated complexes demonstrated six coordinate structures in the solid and solution sate. Biological activity of the ligands and their metal complexes were screened for their antimicrobial activity against four bacterial species (Escherichia coli and Enterobacter (G-)), (Bacillus stubtilis and Staphylococcus aureus (G+)). [ABSTRACT FROM AUTHOR]

Two series of metal complexes were prepared in this study, the first set from reaction of metal salts with Schiff base (HL1) as a primary ligand (which prepared by condensation of Benzdine, 2-hydroxynaphthaldehyed and 9-anthracen carbaldehyed in a one pot step with 1:1:1 molar ratio. The second series was synthesized by reaction of two mixed ligands [HL1] and 1,10-phenanthroline [L2] with the metal saltes in a 1:1:1 molar ratio. The Schiff base ligand and mixed ligand chelates characterization based on spectroscopic method; FTIR, UV-Vis, 1H-NMR along with elemental analysis, metal content, melting point, magnetic susceptibility and conductance measurements. The Schiff base ligand and mixed ligand complexes were found to have the general formulae [M(L1)2(H2O)2]. H2Oand [M(L1)(1,10phen)] Cl. H2O, where (M=Mn(II), Co(II), Cu(II), Ni(II), Zn(II) and Cd(II) respectively. Octahedral geometrical structures were proposed for (HL1) complexes while a tetrahedral structure was proposed for the mixed ligand complexes. The interactions of prepared compounds with DNA were investigated by gel electrophoresis and Ultra-Violet spectroscopy. The results of DNA binding and cleavage experiments displayed that some metal complexes were able to interact with DNA in intercalative mode, these results suggested the possible utilization of metal complexes for pharmaceutical applications. [ABSTRACT FROM AUTHOR]

The preparation, spectroscopic characterisation of complexes derived from the mixed ligands with CdII, ZnII and CoII metal ions with Schiff base, Dithiocarbamates (DTCs) and 8-Hydroxyquinoline are reported. The compounds that prepared have been defined via; chloride content, F.T-IR, UV-Vis ¹H-NMR spectroscopy and C.H.N.S, as well as conductance and magnetic susceptibility.All data which collected from such methods specified complexes with 6 coordinates in solution and solid states. The biologicalactivity that is related to all the prepared compounds which were screened for their antimicrobial activitiesagainst (G+ and (G-)). The data that collected from biological activity indicate that complexes will have extra activity against such tested bacteria in comparison to that in free ligands. [ABSTRACT FROM AUTHOR]