scholarly journals Synthesis, fluorescent studies, antioxidative and α-amylase inhibitory activity evaluation of some lanthanide(III) complexes

2018 ◽  
Vol 83 (5) ◽  
pp. 561-574 ◽  
Author(s):  
Surya Philip ◽  
Soosan Thomas ◽  
K. Mohanan
Keyword(s):  
Metal Complexes ◽  
Inhibitory Activity ◽  
Metal Ion ◽  
Antioxidant Property ◽  
Azomethine Nitrogen ◽  
Spectral Studies ◽  
Quantum Yields ◽  
Heterocyclic Ligand ◽  
Relative Quantum ◽  
Xrd Patterns

A novel heterocyclic ligand, viz. 1,2-dihydro-1,5-dimethyl-4-[[1-2- -oxo-2H-1-benzopyran-3-yl)ethylidene]amino]-2-phenyl-3H-pyrazol-3-one, was prepared by condensing 3-acetylcoumarin with 4-aminoantipyrine. This ligand is versatile in forming complexes with lanthanum(III), praseodymium(III), samarium(III), gadolinium(III) and dysprosium(III) ions. The ligand and the metal complexes were characterized through various physicochemical and spectral studies. The spectral studies revealed that the ligand is coordinated to the metal ion in a bidentate fashion, through the azomethine nitrogen and the oxygen atom of the pyrazolone ring. The powder XRD patterns of ligand and the dysprosium(III) complex were studied. The photoluminescent properties of ligand and metal complexes were evaluated and the relative quantum yields were determined. It was observed that in all cases the metal ions enhanced the luminescence intensity. The ?-amylase inhibitory activity of the ligand and the metal complexes was evaluated using the method of Apostolidis. The metal complexes exhibited increased activity compared to the ligand. The antioxidant property was also examined using the DPPH assay and the metal complexes were found to be more potent antioxidants than the ligand.

scholarly journals Synthesis, Spectral Characterization and Biological Activity of Metal(II) Complexes of 2,4,5-Trimethoxybenzaldehyde-S-Benzyldithiocarbazone

2019 ◽  
Vol 32 (1) ◽  
pp. 209-214
Author(s):  
Deepak Kumar ◽  
Arun Kumar Singh ◽  
Ajay Kumar ◽  
Dayanand Prasad ◽  
Vijay Kumar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Metal Complexes ◽  
Metal Ion ◽  
Free Ligand ◽  
Azomethine Nitrogen ◽  
Octahedral Symmetry ◽  
Spectral Bands ◽  
Distorted Octahedral ◽  
And Staphylococcus Aureus

2,4,5-Trimethoxybenzaldehyde was condensed with S-benzyldithiocarbazate to give Schiff base 2,4,5-trimethoxy benzaldehyde-S-benzyldithiocarbazone (BBTC), which was used for complexation with Mn(II), Fe(II) and Co(II) metal ions. The complexes were formulated as M(BBTC)2X2 where X is Cl−, NO3− and CH3COO−. The FTIR spectra of the metal complexes in comparison to that of free ligand suggested the coordination through azomethine nitrogen and thion sulphur forming six membered chelating with metal ion. The magnetic susceptibility and electronic spectral bands revealed octahedral symmetry (Oh) around Mn(II) but tetragonally distorted octahedral symmetry (D4h) of Fe(II) and Co(II) complexes. The positive value of Dt for Fe(II) (68.42-135.2 cm-1) and Co(II) (263-280 cm-1) clearly indicated elongation along z-axis in these complexes which was also supported by the less value of Dq(z) than Dq(xy) for the metal complexes. The ligand as well as its metal complexes have been found active against the bacteria Escherichia coli and Staphylococcus aureus, and antibacterial activity of the free ligand has been observed to have enhanced in metal complexes.

SYNTHESIS, SPECTRAL STUDIES, STRUCTURAL EVALUATION AND ANTIMICROBIAL ACTIVITY OF SOME NOVEL C R(III) COMPLEXES CONTAINING TETRADENTATE MACROCYCLIC LIGANDS

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (06) ◽  
pp. 20-29
Author(s):  
S Shukla ◽  
◽  
S. Gautam ◽  
S Chandra ◽  
A. Kumar
Keyword(s):  
Metal Complexes ◽  
Metal Ion ◽  
Metal Salt ◽  
Condensation Reaction ◽  
Macrocyclic Ligand ◽  
Agar Plate ◽  
Macrocyclic Ligands ◽  
Diffusion Method ◽  
Spectral Studies ◽  
Spectral Techniques

A string of novel coordination compounds of Cr(III) complexes have been derived and characterized from the macrocyclic ligands (L 1 -L 2 ) carried out by condensation reaction between ligands and the subsequent metal salt. The chemical composition of ligand was determined by analytical and spectral techniques i.e. elemental analysis, IR and Mass spectrocopy. Spectral techniques revealed tetradentate [N 4 ] the nature of ligand and its coordination mode to metal ion through nitrogen donor atoms. Metal complexes were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, IR, electronic spectra, ePR studies. The geometry of these complexes was ascertained by molecular modelling study by using Gaussian 09 program. All metal complexes were found to exhibit octahedral geometry around the metal ion. The newly synthesized macrocyclic ligands and metal complexes were subjected for antimicrobial screening to determine the inhibition and control against tested microorganisms, bacteria ( S.lutea , S.aureus, S.albus and E.coli ) and fungi ( A.fulviceps, U . hordei, A. niger and P.catinus ) by using disc diffusion method and agar plate technique, respectively. The experimental results suggest that metal complexes exhibit enhanced inhibition zone than free macrocyclic ligand.

scholarly journals THE METAL COMPLEXES OF NOVEL SCHIFF BASE CONTAINING ISATIN: CHARACTERIZATION, ANTIMICROBIAL, ANTIOXIDANT AND CATALYTIC ACTIVITY STUDY

2019 ◽  
pp. 206-210
Author(s):  
VAIRALAKSHMI M ◽  
PRINCESS R ◽  
JOHNSON RAJA S
Keyword(s):  
Catalytic Activity ◽  
Metal Complexes ◽  
1H Nmr ◽  
Metal Ion ◽  
Analytical Data ◽  
Free Ligand ◽  
Molar Conductance ◽  
Diffusion Method ◽  
Spectral Studies ◽  
Standard Drug

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.

scholarly journals Synthesis, Spectroscopic, and Antimicrobial Studies on Bivalent Nickel and Copper Complexes of Bis(thiosemicrbazone)

2007 ◽  
Vol 2007 ◽  
pp. 1-7 ◽  
Author(s):  
Sulekh Chandra ◽  
Smriti Raizada ◽  
Monika Tyagi ◽  
Archana Gautam
Keyword(s):  
Metal Complexes ◽  
Metal Ion ◽  
Copper Complexes ◽  
Free Ligand ◽  
Antimicrobial Properties ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Central Metal ◽  
Antimicrobial Studies

A series of metal complexes of Cu(II) and Ni(II) having the general composition[M(L)X2]with benzil bis(thiosemicarbazone) has been prepared and characterized by element chemical analysis, molar conductance, magnetic susceptibility measurements, and spectral (electronic, IR, EPR, mass) studies. The IR spectral data suggest the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, an octahedral geometry has been assigned for Ni(II) complexes but a tetragonal geometry for Cu(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties.

scholarly journals Synthesis, Characterization and Antimicrobial studies of Schiff base Ligand from amino acid L-arginine and its Cu(II), Ni(II),Co(II) complexesIJCTR.2019.130201

2020 ◽  
Vol 13 (2) ◽  
pp. 1-8
Author(s):  
R.K. Sree Devi ◽  
S. SudhaKumari
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Metal Ion ◽  
Electronic Absorption Spectra ◽  
Magnetic Data ◽  
Azomethine Nitrogen ◽  
Diffusion Method ◽  
Significant Activity ◽  
Antimicrobial Studies

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.

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
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Analytical Data ◽  
Molar Conductance ◽  
Molar Ratio ◽  
Azomethine Nitrogen ◽  
Spectral Studies ◽  
Tetrahedral Geometry ◽  
H Nmr ◽  
Carboxylate Oxygen

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.

scholarly journals Synthesis, Structural Investigations and Antimicrobial Activities of Homo Binuclear Complexes Derived from 2-Amino-4-chlorophenol

2020 ◽  
Vol 32 (4) ◽  
pp. 759-764
Author(s):  
K. Savitha ◽  
S. Vedanayaki
Keyword(s):  
Metal Complexes ◽  
Magnetic Moment ◽  
Dna Cleavage ◽  
Metal Ion ◽  
Antimicrobial Activities ◽  
Molar Conductance ◽  
Azomethine Nitrogen ◽  
Planar Geometry ◽  
Binuclear Complexes ◽  
Central Metal

Co(II), Ni(II) and Cu(II) homo binuclear Schiff base metal complexes were synthesized from terephthalaldehyde and 2-amino-4-chlorophenol in methanol using template method. The structure of the ligand and its metal complexes were established by elemental, molar conductance, UV, magnetic moment, IR, 1H & 13C NMR, EPR, mass, thermal and PXRD. Molar conductance values showed that all complexes were non-electrolytic in nature. The IR spectral data provides the coordination of azomethine nitrogen and oxygen with central metal ion. UV, ESR and magnetic moment values suggest square planar geometry for Co(II), Ni(II) and Cu(II) complexes. TGA and DSC analysis data show the thermal stability of the ligand and its metal complexes. The crystalline nature of ligand and its metal complexes were investigated by powder-XRD. The DNA cleavage activities of all the complexes assayed on PUC18 DNA shows nuclease ability.

scholarly journals Synthesis, Spectroscopic Characterization and Biological Activities of Transition Metal Complexes Derived from a Tridentate Schiff Base

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
J. Senthil Kumaran ◽  
S. Priya ◽  
N. Jayachandramani ◽  
S. Mahalakshmi
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Metal Ion ◽  
Biological Activities ◽  
Bacterial Species ◽  
Spectroscopic Characterization ◽  
Structural Features ◽  
Fungal Species ◽  
Spectral Studies ◽  
Central Metal

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.

scholarly journals Synthesis and Characterization of Transition Metal Complexes with

2009 ◽  
Vol 2 (1) ◽  
pp. 114-126 ◽  
Author(s):  
Y. Prashanthi ◽  
Shiva Raj
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Schiff Bases ◽  
Transition Metal Complexes ◽  
Azomethine Nitrogen ◽  
Spectral Studies ◽  
Activity Data ◽  
Metal Chlorides ◽  
Antimicrobial Studies ◽  
Bacteria And Fungi

The Schiff bases namely MIMFMA, MIMTMA and MIPMA have been prepared by reacting 3-amino-5-methyl isoxazole with 5-methyl furan-2-carboxyaldehyde, 5-methyl thiphene-2-carboxaldehyde and pyridine-2-carboxaldehyde. The Cu(II), Ni(II), Co(II), Zn(II) and VO(IV) have been prepared by reacting metal chlorides with those  Schiff bases in an alchololic medium. The complexes are electrolytes in DMSO. These have been  characterized by using elemental analysis, IR, UV-VIS, 1H, 13C, mass spectra, magnetic susceptibility, conductance measurements and thermo gravimetric studies. The complexes were found to have composition ML2. On basis of elemental and spectral studies, six coordinated geometry is assigned for these complexes. The Schiff bases act as neutral and bidentate and coordinate through the azomethine nitrogen and furfural oxygen, thiophene sulphur and pyridine nitrogen, respectively. The synthesized ligands and their metal complexes were screened against bacteria and fungi.  The activity data show that the metal complexes are more potent than the parent Schiff bases. Keywords; Schiff bases; Transition metal complexes; Spectral studies; Antimicrobial studies. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2732                  J. Sci. Res. 2 (1), 114-126 (2010)   

scholarly journals Synthesis, Characterization and Antimicrobial Activity of Ni(II), Zn(II), and Cd(II) Complexes of 3/4-Bromo-Benzoic Acid (Phenyl-Pyridine-2-yl-Methylene)-Hydrazide Ligand

2020 ◽  
Vol 9 (4) ◽  
pp. 1529-1537
Keyword(s):  
Antimicrobial Activity ◽  
Benzoic Acid ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Metal Ion ◽  
Trichophyton Rubrum ◽  
Salmonella Typhi ◽  
Spectral Studies ◽  
Mass Analysis ◽  
Uv Visible

New transition metal complexes [Ni(L)2], [Zn(L)Cl], [Zn(L)2] and [Cd(L)2] were synthesized from 3-bromo-benzoic acid (phenyl-pyridin-2-yl-methylene)-hydrazide (3Bbpph) and 4-bromo-benzoic acid (phenyl-pyridin-2-yl-methylene)-hydrazide (4Bbpph) ligands and were characterized by different physicochemical and spectral studies - IR, elemental, UV Visible, 1H NMR spectra and mass analysis. The data revealed the presence of tetra-coordinate [Zn (L)Cl], whereas [Ni(L)2], [Zn(L)2], and [Cd(L)2] complexes consist of metal ion coordinated with two molecules of ligand to form octahedral geometry. The ligands act as monobasic, tridentate, and coordinated through enolate-O, azomethine-N, and pyridyl-N atoms. The antimicrobial activity of the ligands and metal complexes was investigated against Staphylococcus Aureus, Streptococcus Pyogenes, Escherichia coli, Salmonella typhi, Candida Albicans and Trichophyton Rubrum which revealed that the metal complexes exhibit greater activity than the parent ligands.

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