scholarly journals Macrocyclic complexes: Synthesis and characterization

2010 ◽  
Vol 75 (4) ◽  
pp. 475-482 ◽  
Author(s):  
Dharmpal Singh ◽  
Krishan Kumar

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.

2010 ◽  
Vol 75 (5) ◽  
pp. 629-637 ◽  
Author(s):  
Gajendra Kumar ◽  
Dharmendra Kumar ◽  
C.P. Singh ◽  
Amit Kumar ◽  
V.B. Rana

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.


2007 ◽  
Vol 72 (11) ◽  
pp. 1069-1074 ◽  
Author(s):  
Pal Singh ◽  
Ramesh Kumar

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.


2010 ◽  
Vol 75 (2) ◽  
pp. 217-228 ◽  
Author(s):  
Dharmpal Singh ◽  
Krishan Kumar ◽  
Ramesh Kumar ◽  
Jitender Singh

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.


2001 ◽  
Vol 8 (4) ◽  
pp. 189-194 ◽  
Author(s):  
Marek Z. Wisniewski ◽  
Tadeusz Glowiak ◽  
Adam Opolski ◽  
Joanna Wietrzyk

Complexes of 2-(4-thiazolyi)benzimidazole (thiabendazole, THBD) with Co(II), Ni(II), Cu(ll) of general formula ML2(NO3)2 H2O and complexes of Pd(II) and Pt(II) of general formula ML2Cl2 H2O have been obtained and characterized by elemental analyses, IR and far IR spectroscopy and magnetic measurements. The X-ray crystal structure of the copper(II) complex has been determined. The in vitro cell proliferation inhibitory activity of these compounds was examined against human cancer cell lines A 549 (lung carcinoma), HCV-29 T (urinary bladder carcinoma), MCF-7 (breast cancer), T47D (breast cancer), MES-SA (uterine carcinoma) and HL-60 (promyelocytic leukemia). Pt-THBD has been found to exhibit an antileukemic activity of the HL-60 line cells matching that of an arbitrary criterion.


2011 ◽  
Vol 76 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Pal Singh ◽  
Vidhi Grover ◽  
Krishan Kumar ◽  
Kiran Jain

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.


2020 ◽  
Vol 85 (5) ◽  
pp. 637-649
Author(s):  
Branka Drazic ◽  
Mirjana Antonijevic-Nikolic ◽  
Zeljko Zizak ◽  
Sladjana Tanaskovic

Two new complexes with the general formula [Cu2(L)tpmc] (ClO4)3?nH2O (tpmc = N,N?,N??,N???-tetrakis(2-pyridylmethyl)- -1,4,8,11-tetraazacyclotetradecane, L = N-methylglycine, n = 3; L = N,N- -dimethylglycine, n = 2) were isolated and their composition, some physical and chemical properties and geometries were proposed based on elemental analysis (C, H, N), conductometric and magnetic measurements and spectroscopic data (UV?Vis, FTIR). It is evident that the complexes are binuclear and an exo coordination mode of the macrocyclic ligand in the boat conformation was proposed. The co-ligands are coordinated as a bridge using both oxygen atoms of the OCO- group. The cytotoxic activity of Cu(II) complexes as well as their Co(II) analogs, the starting ligands and the free salts were tested against human cervix adenocarcinoma cell line (HeLa), human chronic myelogenous leukemia cells (K562), human breast cancer cell line (MDA-MB-453), and a non-cancerous cell line, human embryonic lung fibroblast (MRC-5). The IC50 values for the Cu(II) complexes were from 21.6?0.04 to 66.1?0.8, and for the Co(II) analogs were within the range from 8.8?0.74 to 15.40?1.52. All four complexes were tested for their antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and the yeast Candida albicans.


2016 ◽  
Vol 4 (03) ◽  
pp. 15-19
Author(s):  
Sabir Ali ◽  
Vandna Singh

Synthesis of macrocyclic metal complexes of Cr(III) and Fe(III) by the condensation of benzil dihydrazone with 1H-indole-2, 3-dione.The metal complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility, thermal analysis, ESR, infrared, 1H NMR and UV-visible spectroscopy. On the bases of these studies, a fivecoordinate square pyramidal geometry is proposed for all the metal complexes. In vitro antibacterial activity of macrocyclic metal complexes exhibited good results.


2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Sanjay Singh ◽  
Hardeo S. Yadav ◽  
Ashok Kumar Yadava ◽  
Devendra Pratap Rao

Oxovanadium(IV) complexes of the type [VO(mac)]SO4(where mac = tetraaza macrocyclic ligands derived by condensation of thenil with 1,4-diaminobenzene or 3,4-diaminopyridine and their reaction withβ-diketones) have been prepared using vanadyl ion as kinetic template. The prepared macrocyclic complexes were characterized by elemental analyses, molar conductance, magnetic moments, and infrared, electronic, and electron spin resonance data. From the spectroscopic studies, five-coordinate square-pyramidal geometry for the VO2+complexes have been proposed wherein derived ligands act as tetradentate chelating agents.


2010 ◽  
Vol 7 (3) ◽  
pp. 813-820 ◽  
Author(s):  
Gajendra Kumar ◽  
Dharmendra Kumar ◽  
Shoma Devi ◽  
Amit Kumar ◽  
Rajeev Johari

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.


2018 ◽  
Vol 5 (1) ◽  
pp. 51-63 ◽  
Author(s):  
Hanaa A. El-Boraey ◽  
Ohyla A. EL-Gammal

Introduction:A new series of mononuclear Fe(II), Co(II), Ni(II), Cu(II) and Pd(II) complexes correspond to tetradentate macrocyclic nitrogen ligandi.e.naphthyl-3,4:10,11-dibenzo,7-methylene,8-methyl,6-phenyl-1,5,9,13-tetraazacyclohexadecane-5,8-diene-2,12-dione metal(II) complexes, have been synthesized by the template condensation reaction.Methods:The complexes have been characterized by elemental analysis, spectral (IR, UV–Vis, and ESR, molar conductivity, and magnetic as well as thermal analysis measurements.Results:On the basis of above studies, an octahedral geometry has been proposed for all complexes except Cu(II) nitrate complex that adopt square pyramidal geometry, and square planar geometry for Pd(II) chloride complex, respectively.Conclusion:The thermal behavior and the kinetic parameters of degradation were determined using Coats-Redfern and Horowitz-Metzger methods. Moreover, thein vitroantitumor activity of the some synthesized complexes against human breast and human hepatocarcinoma cell lines (MCF-7) and (HePG2), respectively has been studied.


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