scholarly journals Trivalent metal ion directed synthesis and characterization of macrocyclic complexes

2007 ◽  
Vol 72 (11) ◽  
pp. 1069-1074 ◽  
Author(s):  
Pal Singh ◽  
Ramesh Kumar
Keyword(s):  
Metal Ion ◽  
Magnetic Measurements ◽  
Magnetic Moments ◽  
Macrocyclic Ligand ◽  
Far Infrared ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Molecular Weight Determination ◽  
Trivalent Metal ◽  
Pyramidal Geometry

A novel series of complexes of the type [M(TML)X]X2, where TML is a tetradentate macrocyclic ligand, M = Cr(III), Mn(III) or Fe(III), X = Cl-, CH3COO- or ? NO3, were synthesized by template condensation of dibenzoyl and thiocarbohydrazide in the presence of trivalent metal salts in a methanolic medium. The complexes were characterized with the help of elemental analyses, conductance measurements, molecular weight determination, magnetic measurements, electronic, NMR, infrared and far infrared spectral studies. The electronic spectra together with the magnetic moments suggest five coordinate square pyramidal geometry for these complexes. The molar conductance indicates them to be 1:2 electrolytes.

scholarly journals Synthesis, physical characterization and antimicrobial activity of trivalent metal Shiff base complexes

2010 ◽  
Vol 75 (5) ◽  
pp. 629-637 ◽  
Author(s):  
Gajendra Kumar ◽  
Dharmendra Kumar ◽  
C.P. Singh ◽  
Amit Kumar ◽  
V.B. Rana
Keyword(s):  
Antimicrobial Activity ◽  
Schiff Base ◽  
Magnetic Measurements ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Trivalent Metal ◽  
E Coli ◽  
Pyramidal Geometry ◽  
Shiff Base ◽  
Square Pyramidal Geometry

M(III) complexes of Cr, Mn and Fe with a Schiff base derived from 2-amino-4-ethyl-5-hydroxy benzaldehyde and thiocarbohydrazide were synthesized and characterized by several techniques, including elemental analysis (C,H,N), molar conductance measurements, magnetic measurements, and electronic, mass and IR spectral studies. Based on these studies, a fivecoordinated square pyramidal geometry for all the complexes was proposed. The Schiff base ligand and the complexes were also tested for their antimicrobial activity (against the bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus megaterium, and the fungi Kluyveromyces fragilis, Rhodotorula rubra, Candida albicans and Trichoderma reesei) to assess their inhibiting potential. An attempt was also made to correlate the antimicrobial activity with the geometry of the complexes. All complexes were found to be less active against the pathogens E. coli, S. aureus and P. aeruginosa. The Cr(III) complex showed the best antimicrobial activity, but the ligand alone was found to be active against the fungus T. reesei.

scholarly journals Synthesis and characterization of divalent metal complexes of the macrocyclic ligand derived from isatin and 1,2- diaminobenzene

2011 ◽  
Vol 76 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Pal Singh ◽  
Vidhi Grover ◽  
Krishan Kumar ◽  
Kiran Jain
Keyword(s):  
Magnetic Measurements ◽  
Macrocyclic Ligand ◽  
Far Infrared ◽  
Antibacterial Activities ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Distorted Octahedral Geometry ◽  
Bacterial Strains ◽  
Infrared Spectral

A novel series of complexes of the type [M(C28H18N6)X2], where M=Co(II), Ni(II), Cu(II) or Zn(II) and X=Cl-, NO3- or CH3COO-, were synthesized by template condensation of isatin and 1,2-diaminobenzene in methanolic medium. The complexes were characterized with the help of various physico-chemical techniques, such as elemental analyses, molar conductance measurements, magnetic measurements, and NMR, infrared and far infrared spectral studies. The low value of molar conductance indicates them to be non-electrolytes. Based on various studies, a distorted octahedral geometry may be proposed for all the complexes. All the synthesized macrocyclic complexes were also tested for their in vitro antibacterial activity against some pathogenic bacterial strains. The MIC values shown by the complexes against these bacterial strains were compared with those of the standard antibiotics linezolid and cefaclor. Some of the complexes showed good antibacterial activities.

scholarly journals Macrocyclic complexes: Synthesis and characterization

2010 ◽  
Vol 75 (4) ◽  
pp. 475-482 ◽  
Author(s):  
Dharmpal Singh ◽  
Krishan Kumar
Keyword(s):  
Magnetic Measurements ◽  
Macrocyclic Ligand ◽  
Macrocyclic Complexes ◽  
Metal Salts ◽  
Trivalent Metal ◽  
Pyramidal Geometry ◽  
Elemental Analyses ◽  
Square Pyramidal Geometry ◽  
In Vitro Antifungal Activity

A novel series of complexes of the type [M(C28H24N4)X]X2, where M = Cr(III), Fe(III) or Mn(III), X = Cl?, NO3 ?, CH3COO? and (C28H24N4) corresponds to the tetradentate macrocyclic ligand, were synthesized in methanolic media by the template condensation of 1,8-diaminonaphthalene and 2,3- butanedione (diacetyl) in the presence of trivalent metal salts. The complexes were characterized by elemental analyses, conductance and magnetic measurements, and UV/Vis, NMR and IR spectroscopy. Based on these studies, a five-coordinate square pyramidal geometry for all the prepared complexes is proposed. All the synthesized macrocyclic complexes were tested for their in vitro antifungal activity against some fungal strains viz. Aspergillus niger and A. fumigatus. The results obtained were compared with the standard antifungal drug fluconazole.

scholarly journals Synthesis, Characterization and in vitro Antifungal Screening of Manganese(II) and Copper(II) Complexes of Hexaaza [N6] Macrocyclic Ligand

1970 ◽  
Vol 25 ◽  
pp. 46-52
Author(s):  
U. Kumar ◽  
S. Chandra
Keyword(s):  
Metal Ion ◽  
Hyperfine Splitting ◽  
Macrocyclic Ligand ◽  
Chemical Society ◽  
Molar Conductance ◽  
Epr Spectra ◽  
Spectral Studies ◽  
Conductivity Measurements ◽  
G Value

New manganese(II) and copper(II) complexes of 12-membered macrocyclic Schiffbase ligand containing thiosemicarbazone moiety have been prepared of generalcomposition [MLX2] where M = Mn(II) or Cu(II), L = 3,4,9,10–tetra-2-furanyl-1,2,5,6,8,11-hexaazacyclododeca-7,12-dithione-2,4,8,10–tetraene, X = Cl-, NO3- and NCS-. Thecomplexes have been characterized by elemental analysis, molar conductance, magneticsusceptibility measurements and spectral (IR, electronic, EPR and mass) analyses. The IRspectra of complexes suggested that ligand is coordinated to the metal ion through iminenitrogen atoms. On the basis of spectral studies, an octahedral and tetragonal geometry hasbeen assigned for Mn(II) and Cu(II) complexes, respectively. EPR spectra of polycrystallineMn(II) complexes gave an isotropic signal with g value centered around free electron gvalue. EPR spectra of Mn(II) complexes in DMSO showed hyperfine splitting containing sixlines, whereas EPR spectra of polycrystatalline Cu(II) complexes showed anisotropicsignal. Conductivity measurements support the non electrolytic nature of the complexes.Magnetic moment data suggest that reported complexes are paramagnetic and of high spintype. All the examined complexes have also been tested in vitro against a number ofpathogenic fungi. Results indicated that the complexes exhibited good antifungal activities.Keywords: Macrocyclic, octahedral, antifungal, tetragonal, anisotropic.DOI:  10.3126/jncs.v25i0.3284Journal of Nepal Chemical Society Volume 25, 2010 pp 46-52

scholarly journals Synthesis and Characterization of Biologically Active 10-Membered Tetraazamacrocyclic Complexes of Cr(III), Mn(III), and Fe(III)

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Dharam Pal Singh ◽  
Vandna Malik ◽  
Ramesh Kumar
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Metal Ion ◽  
Inhibitory Concentration ◽  
Macrocyclic Ligand ◽  
Far Infrared ◽  
Carbonyl Oxygen ◽  
Biologically Active ◽  
Spectral Studies ◽  
Bacterial Strains

A new series of macrocyclic complexes of type [M(TML)X]X2; where M = Cr(III), Mn(III), or Fe(III); TML is tetradentate macrocyclic ligand and X = Cl−1, NO3−1, CH3COO−1 for Cr(III), Fe(III), and X = CH3COO−1 for Mn(III) has been synthesized by template condensation of succinyldihydrazide and glyoxal. The complexes have been formulated as [M(TML)X]X2 due to 1:2 electrolytic natures of these complexes as shown by conductivity measurements. The complexes have been characterized with the help of elemental analyses, molar conductance, electronic, infrared, far infrared spectral studies and magnetic susceptibilities. On the basis of these studies, a five-coordinate distorted square-pyramidal geometry, in which two nitrogens and two carbonyl oxygen atoms are suitably placed for coordination toward the metal ion, has been proposed for all the complexes. The complexes were tested for their in vitro antibacterial activity. Some of the complexes showed remarkable antibacterial activities against some selected bacterial strains. The minimum inhibitory concentration shown by these complexes was compared with minimum inhibitory concentration shown by some standard antibiotics like linezolid and cefaclor.

scholarly journals Synthesis, Physical Characterization and Biological Evaluation of Schiff BaseCr(III), Mn(III) and Fe(III) Complexes

2010 ◽  
Vol 7 (3) ◽  
pp. 813-820 ◽  
Author(s):  
Gajendra Kumar ◽  
Dharmendra Kumar ◽  
Shoma Devi ◽  
Amit Kumar ◽  
Rajeev Johari
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Schiff Base ◽  
Magnetic Measurements ◽  
Biological Evaluation ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Kluyveromyces Fragilis ◽  
Pyramidal Geometry ◽  
Square Pyramidal Geometry

M(III) complexes with Cr, Mn and Fe with Schiff base derived from 2-amino-4-ethyl-5-hydroxy benzaldehyde and oxocarbohydrazide were synthesized and characterized by several techniques using elemental analysis (C, H, N), molar conductance measurements, magnetic measurements, electronic, mass and IR spectral studies. On the bases of these studies, a five coordinated square pyramidal geometry for all these complexes has been proposed and found to be potential antimicrobial agent. The Schiff base ligand and complexes were also tested for their antimicrobial activity (against the bacteriaEscherichia coli, Staphylococcus aureus, Pseudomonas aeruginosaandBacillus megateriumand the fungiKluyveromyces fragilis, Rhodotorula rubra, Candida albicansandTrichoderma reesei) to assess their inhibiting potential. An attempt is also made to correlate the antimicrobial activity with geometry of the complexes. All complexes were found to be less active against the pathogensE.coli, S.aureusandP.aeruginosa. Cr(III) complex showed the best antimicrobial activity, but ligand alone was found to be active against the fungusT.reesei.

scholarly journals Template synthesis and characterization of biologically active transition metal complexes comprising 14-membered tetraazamacrocyclic ligand

2010 ◽  
Vol 75 (2) ◽  
pp. 217-228 ◽  
Author(s):  
Dharmpal Singh ◽  
Krishan Kumar ◽  
Ramesh Kumar ◽  
Jitender Singh
Keyword(s):  
Magnetic Measurements ◽  
Macrocyclic Ligand ◽  
Salmonella Typhi ◽  
Molar Conductance ◽  
Biologically Active ◽  
Distorted Octahedral Geometry ◽  
Bacterial Strains ◽  
In Vitro Antibacterial Activity ◽  
Active Transition

A novel series of complexes of the type [M(C28H24N4)X2], where M = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), X = Cl-, NO3 -, CH3COO- and (C28H24N4) corresponds to the tetradentate macrocyclic ligand, were synthesized by template condensation of 1,8-diaminonaphthalene and diacetyl in the presence of divalent metal salts in methanolic medium. The complexes were characterized by elemental analyses, conductance and magnetic measurements, as well as by UV/Vis, NMR, IR and MS spectroscopy. The low values of the molar conductance indicate non-electrolyte type of complexes. Based on these spectral data, a distorted octahedral geometry may be proposed for all of these complexes. All the synthesized macrocyclic complexes were tested for in vitro antibacterial activity against some pathogenic bacterial strains, viz Bacillus cereus, Salmonella typhi, Escherichia coli and Staphylococcus aureus. The MIC values shown by the complexes against these bacterial strains were compared with the MIC shown by the standard antibiotics linezolid and cefaclor.

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 Physico-chemical characterization and biological screening of metal complexes with Cyanex 301

1970 ◽  
Vol 34 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Tarun Kumar Pal ◽  
Md Ashraful Alam ◽  
Suchitra Rani Paul
Keyword(s):  
Metal Complexes ◽  
Magnetic Measurements ◽  
Chemical Characterization ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Antibacterial And Antifungal Activities ◽  
Physico Chemical ◽  
Dithiophosphinic Acid ◽  
Cyanex 301 ◽  
Antibacterial And Antifungal

New metal complexes of Mg(II), VO(II), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Pd(II) with cyanex 301(L) i.e., bis(2,4,4-trimethylpentyl) dithiophosphinic acid were synthesized. The complexes have been characterized by elemental analysis, molar conductivity, molecular mass determination, magnetic measurements, infrared and electronic spectral studies. The prepared metal complexes have the compositions: 2. [MgL2].H2O, 3. [VOL2], 4. K[MnL3].H2O, 5. [FeL3], 6. K[CoL3].H2O, 7. K[NiL3], 8. K[CuL3] and 9. [PdL2]. The complexes 2, 3 and 9 are assumed to have tetrahedral, square pyramidal and square planar geometries, respectively but the complexes 4 - 8 are octahedral based on experimental data. From magnetic measurements the complexes 2 and 9 are found to be diamagnetic and others are paramagnetic. Measured molar conductance showed that the complexes 2, 3, 5 and 9 are non-electrolytes and rest are electrolytes. Besides, some complexes have shown good antibacterial and antifungal activities. Key words: Cyanex 301; Antibacterial; Antifungal; DMSO; Bis (2, 4, 4-trimethylpentyl) dithiophosphinic acid DOI: 10.3329/jbas.v34i2.6859Journal of Bangladesh Academy of Sciences, Vol. 34, No. 2, 153-161, 2010

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.

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