scholarly journals Synthesis and Characterization of New Lead(II) and Organotin(IV) Complexes of Schiff Bases Derived from Histidine and Methionine

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Har Lal Singh ◽  
J. B. Singh

New Schiff base (HL) ligand is prepared via condensation of isatins and amino acids in 1:1 molar ratio. Metal complexes are prepared and characterized by elemental analysis, molar conductance, electronic, infrared, and multinuclear magnetic resonance (1H NMR, 13C NMR, and 119Sn NMR). The analytical data showed that the ligand acts as bidentate toward metal ions via azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of metal : ligand (1 : 2) to from metal complexes (Pb(II)(L)2 and Bu2Sn(L)2, where L is the Schiff base ligands of histidine and methionine). The conductivity values between 15 and 25 Ω−1cm2 mol−1 in DMF imply the presence of nonelectrolyte species. On the basis of the above spectral studies, distorted octahedral and tetrahedral geometry have been proposed for the resulting organotin(IV) and lead(II) complexes.

2009 ◽  
Vol 6 (3) ◽  
pp. 615-624 ◽  
Author(s):  
K. Siddappa ◽  
K. Mallikarjun ◽  
Tukaram Reddy ◽  
M. Mallikarjun ◽  
C. V. Reddy ◽  
...  

A new complexes of the type ML, MʹL and M″L [where M=Cu(II), Co(II), Ni(II) and Mn(II), Mʹ=Fe(III) and M″=Zn(II), Cd(II) and Hg(II) and L=N1-[(1E)-1-(2-hydroxyphenyl)ethylidene]-2-oxo-2H-chromene- 3-carbohydrazide (HL)] Schiff base have been synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductance, IR,1H NMR, UV-Visible and ESR data. The studies indicate the HL acts as doubly monodentate bridge for metal ions and form mononuclear complexes. The complexes Ni(II), Co(II), Cu(II) Mn(II) and Fe(III) complexes are found to be octahedral, where as Zn(II), Cd(II) and Hg(II) complexes are four coordinated with tetrahedral geometry. The synthesized ligand and its metal complexes were screened for their antimicrobial activity.


2020 ◽  
Vol 32 (12) ◽  
pp. 3197-3202
Author(s):  
Rajeev Kumar ◽  
Sanjay Kumar ◽  
Madhu Bala

The complexes of Co(II), Ni(II), Zn(II) and Cd(II) with isatinylsemicarbazone (IstscabH) and isatinylthiosemicarbazone (IsttscabH) of composition ML2·2H2O [M = Co(II) or Ni(II) and LH = IstscabH or IsttscabH] and ML2 [M = Zn(II) or Cd(II) and LH = IstscabH or IsttscabH] have been synthesized and their antibacterial activity has been investigated. Their inclusion complexes with β-cyclodextrin (β-CD) having composition [ML2(β-CD)·2H2O] or M(C60H88N8O39S2)], [M = Co(II) or Ni(II) and LH = IstscabH or IsttscabH] and [ML2(β-CD) or M(C60H84N6O-37S2)], [M = Zn(II) or Cd(II) and LH = IstscabH or IsttscabH] have also been isolated in solid states. All the synthesized metal complexes have been characterized by analytical data, molar conductance, magnetic susceptibility, electronic and infrared spectral studies. The tetrahedral geometry for Zn(II) and Cd(II) and octahederal geometry for Co(II) and Ni(II) have been assigned on the basis of magnetic susceptibility, UV electronic transitions and IR spectral bands assignments. The structures are retained in inclusion products. A biological activity of Schiff bases, their metal complexes and inclusion products for bacteria Escherichia. coli, Bacillus subtilis and Staphylococcus aureus have been screened and activity explained.


2019 ◽  
Vol 31 (9) ◽  
pp. 2095-2100
Author(s):  
P. Priya ◽  
S. Vedanayaki ◽  
P. Jayaseelan

A new Schiff base ligand (L) N-(4-fluorophenyl)-1-(4-(((4-fluorophenyl)imino)methyl)phenyl)- methaninmine was prepared by the condensation of terephthalaldehyde with 4-fluoroaniline in 1:2 molar ratio. The mononuclear complexes of Co(II), Ni(II), Cu(II) and Zn(II) (1-4) have been synthesized in (2:1) ligand to metal ratio. The composition, geometry and binding sites of ligand with metal complexes were evidenced by various spectral methods like molar conductance, elemental analytical data, magnetic measurements, UV-visible, 1H & 13C NMR, ESI-MS, FT-IR, ESR and thermal analysis. The above studies shows that the ligand is a bidentate and its metal complexes possess an octahedral geometry. Oxidative cleavage of DNA studies of the complexes were monitored by super helix PUC18DNA using a method of agarose gel electrophoresis. Ligand and its metal complexes were screened against gram positive (Staphylococcus aureus), gram negative (Klebsiella pneumoniae) bacterium and fungus (Candida albicans) strains. Antioxidant activities of the metal complexes possess greater activity than ligand.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
R. B. Sumathi ◽  
M. B. Halli

A new Schiff base and a new series of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) complexes were synthesized by the condensation of naphthofuran-2-carbohydrazide and diacetylmonoxime. Metal complexes of the Schiff base were prepared from their chloride salts of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) in ethanol. The ligand along with its metal complexes have been characterized on the basis of analytical data, IR, electronic, mass,1HNMR, ESR spectral data, thermal studies, magnetic susceptibility, and molar conductance measurements. The nonelectrolytic behaviour of the complexes was assessed from the measured low conductance data. The elemental analysis of the complexes confirm the stoichiometry of the type CuL2Cl2and MLCl2where M = Ni(II), Co(II), Cd(II), and Hg(II) and L = Schiff base. The redox property of the Cu(II) complex was investigated by electrochemical method using cyclic voltammetry. In the light of these results, Co(II), Ni(II), and Cu(II) complexes are assigned octahedral geometry, Cd(II), and Hg(II) complexes tetrahedral geometry. In order to evaluate the effect of metal ions upon chelation, both the ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleaving capacity of all the complexes was analysed by agarose gel electrophoresis method.


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.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Suman Malik ◽  
Suparna Ghosh ◽  
Bharti Jain ◽  
Archana Singh ◽  
Mamta Bhattacharya

The present paper deals with the synthesis and characterization of metal complexes of Schiff base derived from xipamide, a diuretic drug. The bidentate ligand is derived from the inserted condensation of 5-aminosulfonyl-4-chloro-N-2,6-dimethyl phenyl-2-hydroxybenzamide (Xipamide) with salicylaldehyde in a 1 : 1 molar ratio. Using this bidentate ligand, complexes of Hg(II), Zn(II), and VO(IV) with general formula ML2 have been synthesized. The synthesized complexes were characterized by several techniques using molar conductance, elemental analysis, magnetic susceptibility, FT-IR spectroscopy, electronic spectra, mass spectra, and particle size analysis. The elemental analysis data suggest the stoichiometry to be 1 : 2 [M : L]. All the complexes are nonelectrolytic in nature as suggested by molar conductance measurements. Infrared spectral data indicate the coordination between the ligand and the central metal ion through deprotonated phenolic oxygen and azomethine nitrogen atoms. Spectral studies suggest tetrahedral geometry for Hg(II), Zn(II) complexes, and square pyramidal geometry for VO(IV) complex. The pure drug, synthesized ligand, and metal complexes were screened for their antifungal activities against Aspergillus niger and Aspergillus flavus. The ligand and its Hg(II) and VO(IV) complexes were screened for their diuretic activity too.


Author(s):  
VAIRALAKSHMI M ◽  
PRINCESS R ◽  
JOHNSON RAJA S

Objectives: The aim of our work was to synthesize novel mixed ligand-metal complexes and evaluation of antimicrobial, antioxidant assay, and analysis of catalytic oxidation of cyclohexane. Methods: The complexes were characterized by means of various physicochemical techniques such as elemental analysis, molar conductance, magnetic susceptibility, infrared (IR), electronic absorption, 1H NMR (proton magnetic resonance), and mass spectral studies. The antimicrobial screening study was done by disc diffusion method. The catalytic activity of the complexes was observed in the oxidation of cyclohexane using eco-friendly hydrogen peroxide as oxidant. Results: On comparing the 1H NMR and IR spectral data of free ligand and its complexes, it was found to be azomethine (CH=N) proton which is formed in the free ligand. During complexation, the azomethine proton is coordinated to the metal ion and the phenolic oxygen is coordinated to the metal ion by deprotonation. The analytical data and mass spectra of the ligand and the complexes confirm the stoichiometry of metal complexes as being of the (MLY)Cl type and the metal to ligand ratio is 1:1. The antimicrobial, antioxidant, and catalytic potential were evaluated and the result shows the better activity of the complexes than the ligand. Conclusion: It was found to be copper(II) and zinc(II) complexes which are effective against all the bacteria when compared to standard drug streptomycin. Copper(II) complex was found to be effective antibacterial agent against Aspergillus niger and Aspergillus flavus in comparison to the standard drug Nystatin. The zinc complex exhibited good catalytic activity.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Vivekanand D. Biradar ◽  
B. H. M. Mruthyunjayaswamy

A series of new coordination complexes of Cu(II), Co(II), Ni(II), Zn(II), Hg(II), Mn(II), and Fe(III) with the Schiff base 3-chloro-N′-[(1E)-(2-hydroxy phenyl)methylene]-6-methoxy-1-benzothiophene-2-carbohydrazide (HL) have been synthesized and characterized by elemental analysis, electrical conductivity measurements, IR spectra,1H NMR, mass spectral data, electronic spectra, magnetic susceptibility, ESR spectra, TGA, and Powder XRD data. The Schiff base behaves as tridentate ONO donor ligand and forms the complexes of the type ML2(metal-ligand) stoichiometry for Cu(II), Co(II), Ni(II), and Mn(II) complexes and ML stoichiometry for Zn(II), Hg(II), and Fe(III) complexes. All the complexes are colored and nonelectrolytes. It is found that Cu(II), Co(II), Ni(II), Mn(II) and Fe(III) complexes have exhibited octahedral geometry whereas Zn(II) and Hg(II) complexes exhibited tetrahedral geometry. The ligand and its metal complexes have been screened for their antibacterial activity againstE. coliandS. aureusand antifungal activity againstA. nigerandA. flavus.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Narendra Kumar Chaudhary ◽  
Parashuram Mishra

A novel Schiff base ligand of type HL was prepared by the condensation of amoxicillin trihydrate and nicotinaldehyde. The metal complexes of Co+2, Ni+2, Cu+2, and Zn+2 were characterized and investigated by physical and spectral techniques, namely, elemental analysis, melting point, conductivity, 1H NMR, IR, UV-Vis spectra, ESR, SEM, and mass spectrometry measurements. They were further analyzed by thermal technique (TGA/DTA) to gain better insight about the thermal stability and kinetic properties of the complexes. Thermal data revealed high thermal stability and nonspontaneous nature of the decomposition steps. The Coats-Redfern method was applied to extract thermodynamic parameters to explain the kinetic behavior. The molar conductance values were relatively low, showing their nonelectrolytic nature. The powder XRD pattern revealed amorphous nature except copper complex (1c) that crystallized in the triclinic crystal system. The EPR study strongly recommends the tetrahedral geometry of 1c. The structure optimization by MM force field calculation through ArgusLab 4.0.1 software program supports the concerned geometry of the complexes. The in vitro antibacterial activity of all the compounds, at their two different concentrations, was screened against four bacterial pathogens, namely, E. coli, P. vulgaris, K. pneumoniae, and S. aureus, and showed better activity compared to parent drug and control drug.


2012 ◽  
Vol 9 (4) ◽  
pp. 1655-1666 ◽  
Author(s):  
A. P. Mishra ◽  
H. Purwar ◽  
Rajendra K. Jain ◽  
S. K. Gupta

Some new Schiff base metal complexes of Co(II), Ni(II) and Cu(II) derived from 4-chlorobenzylidene-2-aminothiazole (CAT) and 2-nitrobenzylidene-2-aminothiazole (NAT) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR, magnetic susceptibility, thermal, electrical conductivity and XRD analysis. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal:ligand) ratio with coordination number 4 or 6. FAB-mass and thermal data show degradation pattern of the complexes. The thermal behavior of metal complexes shows that the hydrated complexes loses water molecules of hydration in the first step; followed by decomposition of ligand molecules in the subsequent steps. The crystal system, lattice parameter, unit cell volume and number of molecules in unit cell in the lattice of complexes have been determined by XRD analysis. XRD patterns indicate crystalline nature for the complexes. The solid state electrical conductivity of the metal complexes has also been measured. Solid state electrical conductivity studies reflect semiconducting nature of the complexes. The Schiff base and metal complexes show a good activity against the Gram-positive bacteria;Staphylococcus aureusand Gram-negative bacteria;Escherichia coliand fungiAspergillus nigerandCandida albicans.


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