scholarly journals Metal Complexes of Macrocyclic Schiff-Base Ligand: Preparation, Characterisation, and Biological Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Riyadh M. Ahmed ◽  
Enaam I. Yousif ◽  
Hasan A. Hasan ◽  
Mohamad J. Al-Jeboori
Keyword(s):  
Biological Activity ◽  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Condensation Reaction ◽  
Free Ligand ◽  
Inhibition Zone ◽  
Square Planar ◽  
Planar Geometries ◽  
Macrocyclic Schiff Base

A new macrocyclic multidentate Schiff-base ligand Na4L consisting of two submacrocyclic units (10,21-bis-iminomethyl-3,6,14,17-tricyclo[17.3.1.18,12]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 NiIIand CuIIcomplexes. Biological activity of the ligand and its metal complexes against Gram positive bacterial strainStaphylococcus aureusand Gram negative bacteriaEscherichia colirevealed 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 ofPseudomonas aeruginosabacteria. There is therefore no inhibition zone.

scholarly journals Synthesis, Characterization and Biological Evaluation of New Schiff Base Ligand derived from 3-hydroxy-benzaldehyde and p-toluidine and its Divalent Metal Ions

2020 ◽  
Vol 71 (4) ◽  
pp. 47-58
Author(s):  
Noreen Mazhar ◽  
Mehwish Aftab ◽  
Tariq Mahmud ◽  
Muhammadasim Raza Basra ◽  
Mansoor Akhtar ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Protein Denaturation ◽  
Condensation Reaction ◽  
Free Ligand ◽  
Biological Evaluation ◽  
Divalent Metal ◽  
Anti Inflammatory

A new Schiff base ligand (L) and its transition divalent metal complexes were prepared by the condensation reaction; Reaction was carried out at 70-80 oC by refluxing equimolar ratio of toluidine and aldehyde by continuous stirring for 5-6 hours. Synthesized ligand and Ni(II), Fe(II), Co(II), Mn(II) and Zn(II) bimetallic complexes were characterized by using FT-IR, UV-visible spectroscopy, AAS, Single crystal X-ray analysis, 1H-NMR, molar conductance. Compounds were screened against two fungus Candida glabrata and Candida albicans by agar tube dilution protocol. In vivo anti-inflammatory activity via induced paw edema method and in vitro results by heat induced protein denaturation method were checked. Synthesized compounds were also showed antioxidant activity by using DPPH (diphenylpicrylhydrazyl) and Trolox was used as standard. These studies show that ligand and almost all metal complexes are reactive towards biological assays against reported standard drugs. Zn-L indicates more activeness for antioxidant activity and free ligand while Co-L recognized as more effective anti-inflammatory drug.

Synthesis, Characterization and Biological Activity of Nitrogen­ Oxygen-Sulfur (NOS) Transition Metal Complexes Derived from Novel S-2,4-dichlorobenzyldithiocarbazate with 5-fluoroisatin

2010 ◽  
Vol 7 (2) ◽  
pp. 67
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
Hadariah Bahron ◽  
Karimah Kassim ◽  
Mohd Asrul Hafaz Mohamad ◽  
Syed Nazmi Sayed Mohamad
Keyword(s):  
Bacillus Subtilis ◽  
Schiff Base ◽  
Metal Complexes ◽  
Condensation Reaction ◽  
Schiff Base Complex ◽  
Inhibition Zone ◽  
Azomethine Nitrogen ◽  
Strong Activity ◽  
Chelating Ligand ◽  
Physico Chemical

A novel Schiff base containing nitrogen-oxygen-sulfur (NOS) donor atoms formed from the condensation reaction of S-2,4-dichlorobenzyldithiocarbazate (S-2,4BDTC) with 5-fluroisatin has been synthesized. Complexes of cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) with this Schiff base have been prepared and characterized using elemental analysis and various physico-chemical techniques. In the cobalt(II) and nickel(II) complexes the Schiff base behaves as a uninegatively charged tridentate nitrogen-oxygen-sulfur (NOS) chelating ligand, bonding through the azomethine nitrogen, thiolate sulfur and carbonylic oxygen of the isatin moiety. However, in the copper(II), zinc(II) and cadmium(II) complexes the Schiff base behaves as a nitrogen-sulfur (NS) bidentate chelating ligand, bonding through the azomethine nitrogen and thiolate sulfur. The Schiff base and the metal complexes were evaluated with respect to antimicrobial activity, which was performed in relation to two selected pathogenic microbials (Bacillus subtilis and Pseudomonas aeruginosa). It was observed that only the zinc Schiff base complex exhibited strong activity against the Bacillus subtilis bacteria with an inhibition zone of 25 mm. 

Synthesis, Characterization and Biological Activity of NitrogenOxygen-Sulfur (NOS) Transition Metal Complexes Derived from Novel S-2,4-dichlorobenzyldithiocarbazate with 5-fluoroisatin

2010 ◽  
Vol 7 (2) ◽  
pp. 67
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
Hadariah Bahron ◽  
Karimah Kassim ◽  
Mohd Asrul Hafiz Muhamad ◽  
Syed Nazmi Sayed Mohamad
Keyword(s):  
Bacillus Subtilis ◽  
Schiff Base ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Condensation Reaction ◽  
Inhibition Zone ◽  
Azomethine Nitrogen ◽  
Strong Activity ◽  
Chelating Ligand ◽  
Physico Chemical

A novel Schiff base containing nitrogen-oxygen-sulfur (NOS) donor atoms formed from the condensation reaction of S-2,4- dichlorobenzyldithiocarbazate (S-2.4BDTC) with 5-fluroisatin has been synthesized. Complexes of cobalt(ll), nickel(ll), copper(ll), zinc(ll) and cadmium(ll) with this Schiff base have been prepared and characterized using elemental analysis and various physico-chemical techniques. In the cobalt(ll) and nickel(II) complexes the SchifJbase behaves as a uninegatively charged tridentate nitrogen-oxygen-sulfur (NOS) chelating ligand, bonding through the azomethine nitrogen, thiolate sulfur and carbonylic oxygen of the isatin moiety. However. in the copper(ll), zinc(II) and cadmium(II) complexes the Schiff base behaves as a nitrogen-sulfur (NS) bidentate chelating ligand, bonding through the azomethine nitrogen and thiolate sulfur. The Schiff base and the metal complexes were evaluated with respect to antimicrobial activity, which was performed in reallion to two selected pathogenic microbials (Bacillus subtilis and Pseudomonas aeruginosa). It was observed that only the zinc Schiffbase complex exhibited strong activity against the Bacillus subtilis bacteria with an inhibition zone of25 mm.

scholarly journals Synthesis and Spectral Studies of 4,4′-(Hydrazine-1,2-diylidenedimethylylidene)-bis-(2- methoxyphenol) and Its Transition Metal Complexes with Promising Biological Activities

2020 ◽  
Vol 32 (7) ◽  
pp. 1768-1772
Author(s):  
Anita Rani ◽  
Manoj Kumar ◽  
Hardeep Singh Tuli ◽  
Zahoor Abbas ◽  
Vinit Prakash
Keyword(s):  
Schiff Base ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Schiff Base Ligand ◽  
Biological Activities ◽  
Condensation Reaction ◽  
Analytical Techniques ◽  
Spectral Studies

The study describes the synthesis, characterization and biological activity of a novel Schiff base ligand and its transition metal complexes. The Schiff base ligand was obtained by a condensation reaction between 4-hydroxy-3-methoxybenzaldehyde (p-vanillin) and hydrazine hydrate using ethanol as solvent. A new series of Ni(II) and Fe(III) complexes were also derived by reaction of prepared Schiff base ligand with NiCl2 and FeCl3. Both the ligand and its metal complexes were characterized by solubility, melting point and elemental analysis. These compounds were further identified by analytical techniques, FTIR, NMR and mass spectrometry. The ligand and its transition metal complexes were also subjected to in vitro biological activities i.e. antimicrobial, antiangiogenic and DNA photo cleavage. For antimicrobial activity compounds were tested against two strains of bacteria and two strains of fungi. Different concentrations of prepared compounds were treated with fertilized chicken eggs and plasmid DNA to find out antiangiogenic and DNA photocleavage activity, respectively.

scholarly journals Synthesis, Spectroscopy, Theoretical, and Electrochemical Studies of Zn(II), Cd(II), and Hg(II) Azide and Thiocyanate Complexes of a New Symmetric Schiff-Base Ligand

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Morteza Montazerozohori ◽  
Kimia Nozarian ◽  
Hamid Reza Ebrahimi
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Structural Parameters ◽  
Free Ligand ◽  
Basis Set ◽  
Cyclic Voltammograms ◽  
Hybrid Functional ◽  
Ft Ir ◽  
C Nmr

Synthesis of zinc(II)/cadmium(II)/mercury(II) thiocyanate and azide complexes of a new bidentate Schiff-base ligand (L) with general formula of MLX2(M = Zn(II), Cd(II), and Hg(II)) in ethanol solution at room temperature is reported. The ligand and metal complexes were characterized by using ultraviolet-visible (UV-visible), Fourier transform infrared (FT-IR),1H- and13C-NMR spectroscopy and physical characterization, CHN analysis, and molar conductivity.1H- and13C-NMR spectra have been studied in DMSO-d6. The reasonable shifts of FT-IR and NMR spectral signals of the complexes with respect to the free ligand confirm well coordination of Schiff-base ligand and anions in an inner sphere coordination space. The conductivity measurements as well as spectral data indicated that the complexes are nonelectrolyte. Theoretical optimization on the structure of ligand and its complexes was performed at the Becke’s three-parameter hybrid functional (B3) with the nonlocal correlation of Lee-Yang-Parr (LYP) level of theory with double-zeta valence (LANL2DZ) basis set using GAUSSIAN 03 suite of program, and then some theoretical structural parameters such as bond lengths, bond angles, and torsion angles were obtained. Finally, electrochemical behavior of ligand and its complexes was investigated. Cyclic voltammograms of metal complexes showed considerable changes with respect to free ligand.

scholarly journals Synthesis, Characterization and Antibacterial Activity of Schiff Base, 4-Chloro-2-{(E)-[(4-Fluorophenyl)imino]methyl}phenol Metal (II) Complexes

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
F. K. Ommenya ◽  
E. A. Nyawade ◽  
D. M. Andala ◽  
J. Kinyua
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Metal Complexes ◽  
Elemental Analysis ◽  
Schiff Base Ligand ◽  
Condensation Reaction ◽  
Molar Conductance ◽  
Diffusion Method ◽  
Elemental Analysis Data ◽  
Ft Ir

A new series of Mn (II), Co (II), Ni (II), Cu (II), and Zn (II) complexes of the Schiff base ligand, 4-chloro-2-{(E)-[(4-fluorophenyl)imino]methyl}phenol (C13H9ClFNO), was synthesized in a methanolic medium. The Schiff base was derived from the condensation reaction of 5-chlorosalicylaldehyde and 4-fluoroaniline at room temperature. Elemental analysis, FT-IR, UV-Vis, and NMR spectral data, molar conductance measurements, and melting points were used to characterize the Schiff base and the metal complexes. From the elemental analysis data, the metal complexes formed had the general formulae [M(L)2(H2O)2], where L = Schiff base ligand (C13H9ClFNO) and M = Mn, Co, Ni, Cu, and Zn. On the basis of FT-IR, electronic spectra, and NMR data, “O” and “N” donor atoms of the Schiff base ligand participated in coordination with the metal (II) ions, and thus, a six coordinated octahedral geometry for all these complexes was proposed. Molar conductance studies on the complexes indicated they were nonelectrolytic in nature. The Schiff base ligand and its metal (II) complexes were tested in vitro to evaluate their bactericidal activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus subtilis and Staphylococcus typhi) using the disc diffusion method. The antibacterial evaluation results revealed that the metal (II) complexes exhibited higher antibacterial activity than the free Schiff base ligand.

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