scholarly journals Synthesis, characterization, thermal, theoretical and antimicrobial studies of Schiff base ligand and its Co(II) and Cu(II) complexes

2020 ◽  
Vol 85 (2) ◽  
pp. 215-225 ◽  
Author(s):  
Palaniswamy Venkittapuram ◽  
Mahalakshmi Dhandapani ◽  
Jonekirubavathy Suyambulingam ◽  
Chitra Subramanian

A Schiff base ligand L was synthesized by condensation of 1,2-diaminoethane with creatinine. The reaction of the ligand with metal chloride salt gives Co(II) and Cu(II) complexes. The synthesized ligand and its metal complexes were characterized by elemental analysis, FT-IR, NMR, UV?Vis, conductivity and magnetic susceptibility measurements as well as thermal analyses. Based on spectral data, tetrahedral geometries have been proposed for the Co(II) and Cu(II) complexes. The molar conductivity data show that the complexes are non-electrolytic in nature. In DFT studies, the geometry of the Schiff base ligand and its Co(II) and Cu(II) complexes were fully optimized using the B3LYP functional together with 6-31g(d,p) and LANL2DZ basis sets. The ligand and its metal complexes were tested against four bacterial species and two fungal species. The results revealed that the metal complexes are more potent against the microbes than the parent ligand.

2016 ◽  
Vol 11 (7) ◽  
pp. 3723-3728
Author(s):  
Soleiman Mahjoub ◽  
Sara Ansari ◽  
Felora Heshmatpour

The Schiff base ligand (E)-3-(2-methoxy benzylidene amino)-2-thioxothiazolidin-4-one (L), was prepared from N-amino rhodanine and 2-methoxy benzaldehyde . Moreover, Its complexes were synthesized by mixing metal chloride Co(II), Cu(II), Ni(II) with the prepared Schiff base ligand. These compounds were characterized by FTIR, 1H NMR, and elemental analysis. The antimicrobial activity of the ligand and its complexes were tested using four pathogenic bacterial and two fungal species. The bacterial species used in the screening were Salmonella typhi and Vibrio cholera (gram negative) and Staphylococcus aureus and Bacillus subtilis (gram-positive). The fungal species were Aspergillus flavus and Aspergillus nigar. The antimicrobial activities of the ligand and its metal complexes were studied by disc agar diffusion method and compared with Ampicillin. Diameter of inhibition zone (mm) including the disc diameter was measured for each treatment. The findings indicated that the CuL, NiL and CoL complexes have good biological activity but the ligand (L) did not had any activity against the microorganisms under identical experimental conditions.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Morteza Montazerozohori ◽  
Kimia Nozarian ◽  
Hamid Reza Ebrahimi

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.


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.


2021 ◽  
Vol 11 (1) ◽  
pp. 3249-3260

Herein, we describe the synthesis and characterization of a Schiff base ligand (E)-N'-(2-hydroxybenzylidene)-4-methoxybenzohydrazide (HBMB) and its Mn(II), Ni(II), and Cu(II) metal complexes (C1-C3) respectively. The ligand HBMB was synthesized by reacting condensation of salicylaldehyde and 4-methoxy benzohydrazide in a 1:1 molar ratio. The structure of HBMB and its metal complexes (C1-C3) were evaluated by using UV-Vis, FT-IR, 1H-NMR, mass spectroscopy as well as on the basis of elemental analysis, conductivity measurements, and thermogravimetric techniques (TGA). The synthesized molecules' tumoricidal properties were performed against human breast cancer (MCF-7) and colon cancer (HT 29) cell lines. The biological results indicated that the ligand, HBMB, and metal complexes possess dose-dependent selective cytotoxicity against the tested carcinoma cells. The synthesized compounds were further evaluated for their in vitro antimicrobial activities against Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and fungal strains (Aspergillus niger).


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
F. K. Ommenya ◽  
E. A. Nyawade ◽  
D. M. Andala ◽  
J. Kinyua

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.


2012 ◽  
Vol 9 (3) ◽  
pp. 1113-1121 ◽  
Author(s):  
A. P. Mishra ◽  
A. Tiwari ◽  
S. K. Gupta ◽  
Rajendra Jain

Some new Schiff base metal complexes of Co(II), Ni(II) and Cu(II) derived from 3-chloro-4-fluoroaniline (HL1) and 4-fluoroaniline (HL2) with 2-thiophenecarboxaldehyde have been synthesized and characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR and magnetic susceptibility. The complexes exhibit coordination number 4 or 6. The complexes are colored and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal: ligand) ratio. FAB-mass data show degradation pattern of the complexes. The Schiff base and metal complexes show a good activity against the bacteria;B. subtilis,E. coliandS. aureusand fungiA. niger,A. flavusandC. albicans. The antimicrobial results also indicate that the metal complexes are better antimicrobial agents as compared to the Schiff bases.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
J. Senthil Kumaran ◽  
S. Priya ◽  
N. Jayachandramani ◽  
S. Mahalakshmi

A new series of Cu (II), Ni (II), Co (II) and Zn (II) complexes have been synthesized from the Schiff base derived from 4-hydroxy-3-methoxybenzylidine-4-aminoantipyrine and 2-aminophenol. The structural features have been determined from their elemental analysis, magnetic susceptibility, molar conductance, Mass, IR, UV-Vis,1H-NMR,13C-NMR and ESR spectral studies. The redox behavior of the copper complex has been studied by cyclic voltammetry. The data confirm that the complexes have composition of ML2type. The electronic absorption spectral data of the complexes propose an octahedral geometry around the central metal ion. All the metal complexes with DNA structure were guided by the presence of inter-molecular C–HO and C–HN hydrogen bonds. The biological activity of the synthesized compounds were tested against the bacterial species such asBacillus subtilis, Staphylococcus aureus, Proteus vulgarisand fungal species such asCandida albicansby thewell-diffusionmethod.


2020 ◽  
Vol 32 (9) ◽  
pp. 2187-2194
Author(s):  
A. SUDHA ◽  
S. ARULMOZHI ◽  
S.J. ASKAR ALI

By condensing pyrene-1-carbaldehyde and 4-aminoantipyrine, a Schiff base ligand, (Z)-1,5-dimethyl-2-phenyl-4-((pyren-1-ylmethylene)- amino)-1H-pyrazol-3(2H)-one and its Cu(II), Ni(II), Co(II) and Zn(II) complexes have been synthesized. The ligand and its metal complexes were characterized by FT-IR, UV-visible, 1H & 13C NMR, ESI-mass spectra and elemental analysis. The antidiabetic and antioxidant activities of the synthesized Schiff base ligand and its metal complexes were studied. The molecular docking study of human pancreatic α-amylase (PDB: 1HNY). Furthermore, Theoretical analysis of geometry optimization and frontier molecular orbital analysis (HOMOLUMO) was accomplished by density functional theory using B3LYP/3-21G*++ basis sets to understand the chemical stability of the synthesized ligand and their metal(II) complexes.


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