scholarly journals Synthesis, Characterization, and Biological Activity of Some Transition Metal Complexes Derived from Novel Hydrazone Azo Schiff Base Ligand

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
C. Anitha ◽  
S. Sumathi ◽  
P. Tharmaraj ◽  
C. D. Sheela

A series of metal(II) complexes ML where M = VO(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from azo Schiff base ligand (N′E)-N′-(5-((4-chlorophenyl)diazenyl)-2-hydroxybenzylidene)-2-hydroxybenzohydrazide and characterized on the basis of elemental analyses, electronic, IR, and 1H NMR spectra, magnetic susceptibility and also by aid of scanning electron microscopy (SEM), X-ray powder diffraction, fluorescence spectral studies, and molar conductivity measurements. Conductivity measurements reveal that the complexes are nonelectrolytes. Spectroscopy and other analytical studies reveal distorted square planar geometry for copper, square-pyramidal geometry for oxovanadium, and tetrahedral geometry for other complexes. Redox behavior of the copper(II) complex has been studied with cyclic voltammetry, and the biological activities of the ligand and metal complexes have been studied against several microorganisms by the well diffusion method. All synthesized compounds can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG) efficiency of the ligand was measured and found to be higher than that of urea and KDP. The SEM image of the copper(II) complex implies that the size of the particles is 50 nm.

2020 ◽  
Vol 32 (7) ◽  
pp. 1768-1772
Author(s):  
Anita Rani ◽  
Manoj Kumar ◽  
Hardeep Singh Tuli ◽  
Zahoor Abbas ◽  
Vinit Prakash

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Nagesh Gunvanthrao Yernale ◽  
Mruthyunjayaswamy Bennikallu Hire Mathada

A novel Schiff base ligandN-(4-phenylthiazol-2yl)-2-((2-thiaxo-1,2-dihydroquinolin-3-yl)methylene)hydrazinecarboxamide(L)obtained by the condensation ofN-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-thioxo-1,2-dihydroquinoline-3-carbaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), and Zn(II) complexes have been characterized by elemental analysis and various spectral studies like FT-IR,1H NMR, ESI mass, UV-Visible, ESR, TGA/DTA, and powder X-ray diffraction studies. The Schiff base ligand(L)behaves as tridentate ONS donor and forms the complexes of type [ML(Cl)2] with square pyramidal geometry. The Schiff base ligand(L)and its metal complexes have been screenedin vitrofor their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage activity of ligand and its metal complexes were studied using plasmid DNA pBR322 as a target molecule by gel electrophoresis method. The brine shrimp bioassay was also carried out to study thein vitrocytotoxicity properties for the ligand and its metal complexes againstArtemia salina. The results showed that the biological activities of the ligand were found to be increased on complexation.


2017 ◽  
Vol 13 (9) ◽  
pp. 6513-6519
Author(s):  
Anil Kumar M R ◽  
Shanmukhappa S ◽  
Rangaswamy B E ◽  
Revanasiddappa M

Transition metal complexes of Cu(II), Co(II), Ni(II), Zn(II), Cd(II) and Mn(II) have been synthesized with the Schiff base ligand 5-Sub-N-(2-mercaptophenyl)salicylideneimine. Elemental analysis of these complexes suggest that these metal ions forms complexes of type ML(H2O)stoichiometry for Cu(II), Co(II), Ni(II), Zn(II), Cd(II) and Mn(II). The ligand behaves as tridentate and forms coordinate bonds through O, S and N atoms. Magnetic susceptibility, IR, UV – Visible, Mass and ESR spectral studies suggest that Cu(II), Ni(II) complexes posses square planar geometry, whereas Co(II), Zn(II), Cd(II) and Mn(II) complexes posses tetrahedral geometry. The complexes were tested for their antimicrobial activity against the bacterial strains Staphylococcus aureus and Bacillus subtilis.The Schiff base metal complexes evaluated for their antifungal activity against the fungi A. niger and C. oxysporum. The DNA cleavage studies of Schiff base complexes werestudied using Calf – Thymus DNA by agarose gel electrophoresis method.


2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
C. Anitha ◽  
C. D. Sheela ◽  
P. Tharmaraj ◽  
V. V. Hema

Azo Schiff base complexes of VO(II), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from 4-((4-chlorophenyl)diazenyl)-2-((p-tolylimino)methyl)phenol (CDTMP). The nature of bonding and the structural features of the complexes have been deduced from elemental analysis, molar conductance, magnetic susceptibility measurements, IR, UV-Vis,1H-NMR, EPR, mass, SEM, and fluorescence spectral studies. Spectroscopic and other analytical studies reveal square-planar geometry for copper, square-pyramidal geometry for oxovanadium, and octahedral geometry for other complexes. The EPR spectra of copper(II) complex in DMSO at 300 K and 77 K were recorded, and its salient features are reported. Antimicrobial studies against several microorganisms indicate that the complexes are more potent bactericides and fungicides than the ligand. The electrochemical behavior of the copper(II) complex was studied by cyclic voltammetry. All the synthesized compounds can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic conversion efficiency of the synthesized azo Schiff base was found to be higher than that of urea and KDP (potassium dihydrogen phosphate). SEM image of copper(II) complex implies the crystalline state and surface morphology of the complex.


2011 ◽  
Vol 2011 ◽  
pp. 1-8
Author(s):  
S. Sumathi ◽  
C. Anitha ◽  
P. Tharmaraj ◽  
C. D. Sheela

Transition metal complexes of various acetylacetone-based ligands of the type ML (where M=  Cu(II), Ni(II), Co(II); L=  3-(aryl)-pentane-2,4-dione) have been synthesized. The structural features have been derived from their elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, H1NMR, mass and ESR spectral studies. Conductivity measurements reveal that all the complexes are nonelectrolytic in nature. Spectroscopic and other analytical data of the complexes suggest square planar geometry for copper(II), cobalt(II), and nickel(II) complexes of 3-(3-phenylallylidene)pentane-2,4-dione and octahedral geometry for other metal(II) complexes. The redox behaviors of the copper(II) complexes have been studied by cyclic voltammetry. The free ligands and their metal complexes have been screened for their in vitro biological activities against bacteria and fungus. The metal(II) complexes are found to possess increased activities compared to those of the free ligands. All synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG) efficiency of the ligands was found to have considerable effect compared to that of urea and KDP.


2020 ◽  
Vol 32 (5) ◽  
pp. 1091-1096
Author(s):  
Netra Pal Singh ◽  
Uma Agarwal ◽  
Anuroop Kumar ◽  
Kaushal Kumar

A new Schiff base ligand (L) [2,2′-((1Z,1′Z)-((4-methyl-1,2- phenylene)bis(azanylidene))bis(methanylylidene))diphenol], derived from condensation of salicyaldehyde and 3,4-diamino toluene. The synthesized ligand was used for complexation with different metal ions Cr(III), Co(II), Zn(II) and Cd(II) using a molar ratio of metal:ligand (1:1). The synthesized ligand and its metal complexes were characterized by TLC, NMR (1H & 13C), UV-visible, mass, FT-IR spectroscopies, elemental analysis, magnetic moment and conductivity measurement. On the basis of above studies the proposed structure of synthesized mononuclear metal complexes have been found to possess tetrahedral geometry while Cr(III) and Co(II) ions possess octahedral geometry. The spectral studies revealed that the synthesized ligand was acting as tetradentate chelating agent and coordinated to metal centre via deprotonated phenolate oxygen and azomethine-N atom. The biological activity of ligand and its metal complexes were screened in vitro against Gram-negative bacteria (Salmonella typhimurium and E. coli), Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and fungus (Aspergillus fumigatus) to ascertain their antibacterial and antifungal properties.


2021 ◽  
Author(s):  
Yasmin mamdoh hussien Ahmed ◽  
Gehad G. Mohamed

Abstract A new tetradentate Schiff base ligand was prepared from condensation of 4,6-dihydroxy-1,3-phenylenediethanone with ethane-1,2-diylbis(oxy)diethanamine. The ligand forms complexes in good yield. The Schiff base and its complexes were characterized by analytical (CHN elemental analyses, solubility, melting point, conductivity) measurements, spectral (IR, UV-vis, 1H NMR and MS) and magnetic measurements. The elemental analyses, Uv-vis spectra, and room temperature magnetic moment data and theoretically through density function theory were used as characterizing techniques in supporting of further interpretation of the complexes structures. The results of elemental analyses, EI-mass and conductivity measurements confirmed the stoichiometry of the ligand and its complexes while the characteristic absorption bands and resonance peaks in IR and NMR spectra confirmed the formation of the ligand frameworks around the metal ions. The octahedral environment for complexes derived from Schiff base ligand have been confirmed on the basis of results of electronic and diffused reflectance spectral studies and magnetic moment measurements. Detailed studies of the thermal properties of the Schiff base ligand and complexes were investigated by thermogravimetric technique. Moreover, the molecular docking into (PDB: 6NE0) was the DNA binding and supports the experimental finding and 6IY0 Crystal structure of conserved hypothetical protein SAV0927 from Staphylococcus aureus subsp. aureus Mu50. The synthesized ligand and its complexes were tested for in vitro antimicrobial activity against Candida albicans, Bacillus subtilis, Aspergillus flavus, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus by using agar-well diffusion method.


2021 ◽  
Vol 33 (6) ◽  
pp. 1222-1228
Author(s):  
R. Selvarani ◽  
S. Balasubramaniyan ◽  
K. Rajasekar ◽  
M. Thairiyaraja ◽  
R. Meenakshi

A new bidentate Schiff base (E)-N′[(E)-3-phenylallylidene]benzene-1,2-diamine derived from the condensation of o-phenylenediamine and cinnamaldehyde and its Mn(II) and Hg(II) complexes were synthesized and characterized by elemental analysis, molar conductance, magnetic moment, electronic spectra, IR, far-IR and NMR (1H & 13C) spectral studies. The elemental analysis and these metal proposed the metal:ligand stoichiometry and molecular formulae of the metal complexes. The molar conductance and electrochemical property indicates monomeric, neutral nature and redox properties of the metal complexes. The UV-visible spectral study supports the octahedral geometry for Mn(II) complex and square planar geometry for Hg(II) complex and further confirmed by magnetic moment. IR spectral data examined the coordination mode but far-IR is useful to identify the metal-ligand vibrations. The geometry, magnetic property and unsymmetrical nature of these metal complexes corroborated by NMR (1H & 13C) spectra. The DFT of Mn(II) complex studied and the structure optimized by B3LYP/Lan L2DZ using Gaussian 09W. Quantum chemical calculations were done by Mullikan population analysis, HOMO-LUMO and molecular electrostatic potential. The in vitro biological screening effects of the investigated complexes were tested against some bacteria and fungus by agar-well diffusion method. The results indicated that Mn(II) and Hg(II) complexes exhibit potentially active than the Schiff base which was further confirmed by pharmacokinetics study. The antioxidant activity of Schiff base and its Mn(II) complex was examined by radical scavenging DPPH method.


2020 ◽  
Vol 13 (2) ◽  
pp. 1-8
Author(s):  
R.K. Sree Devi ◽  
S. SudhaKumari

Transition metal complexes of Cu(II), Ni(II), Co(II) with a Schiff base Ligand (R,Z)-2-(2-hydroxy-3-methoxybenzylideneamino)-5-guanidinopentanoic acid (HMA-GPA) was synthesized by the condensation of 2-hydroxy-3-methoxybenzaldehyde and L- Arginine. These were characterized by elemental analysis IR, UV, magnetic susceptibility and molar conductivity measurements. The IR spectra of the Ligand HMA-GPA and the metal complexes suggest that the Ligand coordinates the metal ion through azomethine nitrogen, carboxylate Oxygen and Oxygen of the phenolic -OH group. The electronic absorption spectra and magnetic data indicate the Cu(II), Ni(II)complexes to be square planar and Co(II) complex to be octahedral. The metal complexes and the ligand were subjected to antimicrobial studies by Kirby Bayer Disc-diffusion method and found to have significant activity against the selected bacterial and fungal strains under study.


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