Synthesis, spectroscopic, thermal and antimicrobial studies of some novel metal complexes of Schiff base derived from [N-1-(4-methoxy-1,2,5-thiadiazol-3-yl)sulfanilamide] and 2-thiophene carboxaldehyde
ABSTRACT Keeping in view the chemotherapeutic of the sulfa-drugs, Schiff base namely 2-thiophene carboxaldehyde-sulfametrole (HL) and its tri-positive and di-positive metal complexes have been synthesized and characterized by elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance, mass spectra, UV-vis and thermal analysis (TGA and DrTG). The low molar conductance values suggest the non-electrolytic nature of these complexes. IR spectra show that HL is coordinated to the metal ions in a tetradentate manner through hetero five-membered ring-S and azomethine-N, enolic sulfonamide-OH and thiadiazole-N, respectively. Zn(II), Cd(II) and UO2(II) complexes are found to be diamagnetic (as expected). The proposed general formulae of the prepared complexes are [M2X4(HL)(H2O)4] (where M=Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), X=Cl, [Fe2Cl6(HL)(H2O)2], [(FeSO4)2(HL)(H2O)4] and [(UO2)2(HL) (NO3)4].H2O. The thermal behaviour of these chelates shows that the hydrated complexes loss water of hydration in first step in case of uranium complexes followed loss coordinated water followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as DeltaE*, DeltaH*, DeltaS*, and DeltaG* are calculated from the DrTG curves using Coats-Redfern method. The antimicrobial activity of the obtained products was performed using Chloramphenicol and Grisofluvine as standards, indicate that in some cases metallation increase activity than the ligand.
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ABSTRACT: New polymer metal(II) complexes have been synthesized using Schiff base ligand, synthesized by the condensation reaction of 2-hydroxyacetophenone and o-phenylenediamine. The ligand and polymer metal(II) complexes have been characterized by micro-analytical, UV-vis, FT-IR, H-1-NMR spectral studies, as well as magnetic susceptibility and thermal studies. On the basis of spectral studies, a square-planar geometry has been proposed for the copper(II) polymer metal complex; manganese(II) polymer metal complex shows octahedral geometry while other polymer metal complexes have shown tetrahedral geometries. The in vitro antimicrobial activity of the compounds is tested against the bacteria Escherichia coli, Pseudomonas aeruginosa, Bacillius subtilis, Staphylococcus aureus, Salmonella typhi, and the fungi Candida albicans, Microsporum canis, and Aspergillus niger by well diffusion method. The polymer metal complexes show stronger antimicrobial activity than the free ligand and thermal studies were promising after coordination. The polymers represent a novel class of metal-based antimicrobial agents providing large number of opportunities for thermal and antimicrobial applications.Designed Monomers & Polymers 10/2013; 17(3):217-226. DOI:10.1080/15685551.2013.840472 · 0.88 Impact Factor
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ABSTRACT: A novel Schiff base ligand was synthesized by the condensation reaction of 2,6-diformylpyridine and 4-aminoantipyrine in MeOH and characterised by its melting point, elemental analysis, FT-IR, (1)H, (13)C NMR and mass spectroscopic studies. Molecular structure of the ligand was determined by single crystal X-ray diffraction technique. The electrochemical properties of the Schiff base ligand were studied in different solvents at various scan rates. Sensor ability of the Schiff base ligand was investigated by colorimetric and fluorometric methods. Visual colour change of the ligand was investigated in MeOH solvent in presence of various metal ions Na(+), Mg(2+), Al(3+), K(+), Cr(3+), Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Pb(2+). Upon addition of Al(3+) ion into a MeOH solution of the ligand, an orange colour developed which is detectable by naked eye. Fluorescence emission studies showed that the ligand showed single emission band at 630-665nm upon excitation at 560nm. Addition of metal ions Na(+), Mg(2+), K(+), Cr(3+), Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Pb(2+) (1:1M ratio) cause fluorescence quenching, however addition of Al(+3) resulted in an increase in fluorescence intensity. No significant variation was observed in the fluorescence intensity caused by Al(3+) in presence of other metal ions. Therefore, the Schiff base ligand can be used for selective detection of Al(3+) ions in the presence of the other metal ions studied. Copyright © 2014 Elsevier B.V. All rights reserved.Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 10/2014; 136PC:1388-1394. DOI:10.1016/j.saa.2014.10.025 · 2.13 Impact Factor
04/2014; Volume 2014, Article ID 586131, 7 pages. DOI:10.1155/2014/586131