Spectroscopic Investigation of New Schiff Base Metal Complexes (original) (raw)
Related papers
2018
Ni(II) and Cu(II) mono nuclear metal complexes of symmetrical Schiff-base ligands derived from 4,6-diacetyl resorcinol and 2-aminophenol or 4-nitro-2-aminophenol were synthesized. The structure of Schiff-base ligands and their metal complexes were characterized by elemental analysis, H &CNMR, electronic spectroscopy, FT IR, mass, magnetic susceptibility and conductance measurements. The free ligand being tetradentate in nature coordinates through its two nitrogen donars and two oxygen donars in equatorial position, the ligand act as dianionictetradentatedioxadiaza moiety. Both the ligands and the complexes were screened for their antimicrobial activities against Gram positive, Gram negative bacteria and antifungal activities against canditaalbicans.
Four new complexes ciprofloxacin Schiff base were synthesized. The complexes were characterized by using spectroscopic methods. The antibacterial activity of ciprofloxacin Schiff base and their metal complexes were evaluated. a b s t r a c t A new Schiff base (N,N 0-ethylene (bis 1-cyclopropyl-6-fluoro-4-oxo-7-(piperazine-1-yl)-quinoline-3-car-boxylic acid) and its Zn(II), Zr(IV), Ce(IV) and U(VI) complexes were synthesized and characterized by elemental analysis, molar conductance, IR, UV–Vis, 1 H NMR spectra, magnetic moment, thermal analysis as well as mass spectra. The IR results demonstrate that the tetradentate binding mode of the ligand involving azomethine nitrogen and carboxylato oxygen atoms. The calculated bond length and the bond stretching force constant, F(U@O), values for UO 2 bond are 1.744 Å and 654.49 N m À1. The antimicrobial activity of the synthesized ligand and its complexes were screened and the results showed that the metal complexes were found to be more active than free ligand.
Metal complexes of Mn(II), Fe(II), Co(II) and Cd(II) ions with Schiff base ligand 4-{(pyridin-2-ylimino)methyl}phenol derived from condensation of 2-amino pyridine with 4hydroxybenzaldehyde was prepared. The ligand and complexes were isolated from the reaction in the solid form and characterized by conductivity, magnetic moment, TLC, IR, UV-Visible, thermal analysis and some physical measurements. During complexation reaction with transition metal ions Schiff base act as a deprotonated tridentate ligand and IR spectra showed that N and O atoms are coordinated to the central metal atom. The observed values confirmed that the complexes have octahedral geometry. The Schiff base and its metal complexes have been found to have moderate to strong antibacterial activity.
Jordan journal of chemistry, 2013
Five Schiff base ligands bearing a 9-fluorenylidene unit, L1-L5 where (L1= N'-(9H-fluoren-9ylidene)-2-hydroxy-1-naphthohydrazide, L2= N'-(9H-fluoren-9-ylidene)-3-methoxybenzohydrazide, L3= N'-(9H-fluoren-9-ylidene)nicotinohydrazide, L4= N'-(9H-fluoren-9-ylidene) isonicotinohydrazide, and L5=N'-(9H-fluoren-9-ylidene)-2-phenylacetohydrazide) and their [Zn(L)Cl 2 ] and [Cu(L)Cl 2 ] complexes have been synthesized. The characterization and nature of bonding of these complexes were elucidated by elemental analyses, spectral analyses (1 H NMR, FTIR), molar conductivity measurements and thermo-gravimetric studies. Analytical and spectral data revealed that L1 coordinates to metal ions by its imine nitrogen atom and the phenolic oxygen atom with a 1:1 stoichiometry. The L2-L5 coordinates to metal ions by their imine nitrogen atom and the carbonyl oxygen atom with the same as L1 stoichiometry. Most of the free ligands and their complexes exhibit antibacterial activities against a number of pathogenic bacteria. The activities of metal complexes are found to be higher than those of the free ligands.
Cu (II) and Ni (II) Complexes of Schiff Base: Synthesis, Characterization and Antibacterial Activity
International Journal of Advanced Research in Chemical Science, 2020
Cu (II) and Ni (II) metal ions complexes of Schiff base derived from the condensation reaction of appropriate amount of ethane-1,2-diamine, Salicylaldehyde and 2-furfuraldehyde in alcoholic medium. The obtained complexes are characterized by using FTIR spectroscopy, UV-Vis spectroscopy, and Magnetic susceptibility and Conductivity measurements. From the above characterizations, all the synthesized complexes obtained as monomeric structure and the metals center moieties are four-coordinated with square planar geometry. The antibacterial screening activity revealed that Cu(II) complexes showed moderate activity against tested bacterial strains and slightly higher compared to the uncoordinated ligand
Tetradentate Schiff Base Complexes of Transition Metals for Antimicrobial Activity
Arabian Journal for Science and Engineering, 2020
Synthesis of tetradentate Schiff base (SB) complexes of Cu(II), Co(II), and Ni(II) was done by the condensation of 2-aminophenol/o-phenylenediamine and terepthaldehyde in an alcohol medium, and the complexes were characterized by utilizing FTIR, LCMS, and UV-visible analysis. From the analytical, electronic, and magnetic data, octahedral geometry has been proposed for all the complexes. The antibacterial studies were studied for the SB ligands and their complexes against Bacillus subtilis 2393, Proteus vulgaris 426, Klebsiella sp., S. aureus 3160, and Escherichia coli 4604. Their antifungal activities were studied against Aspergilus flavus, Aspergillus niger, Cryptococcus neoformans, and Penicillium chrysogenum. The outcomes revealed that the transition metal complexes revealed good antibacterial and antifungal activities.
Journal of Advanced Scientific Research
We have synthesized a new class of Schiff-base Ligands with m-pthaladehyde and 3-amino benzoic acid. This adduct act as bi-dentate (N8#x38;O) ligand in the formation of mononuclear transition metal complexes of nickel (II), zinc (II), copper (II), cobalt (II), and cadmium (II). Ligand and complexes are characterized and their formation was confirmed by spectroscopic techniques i.e. 1HNMR, FTIR, and UV-Vis spectroscopy. We have synthesized Ligand-metal coordination sphere [M2+(L)2] (where M = Cu(II), Co(II), Cd(II),Ni(II)and Zn(II)) and L=3,3'-((1E,1'E)-(1,3 phenylenebis (methanylylidene)) bis (azanylylidene)) dibenzoic acid and (E)-N-((1H-indol-3-yl) methylene)-4H-1,2,4-triazole-4- amine. Both Ligand and their metal complexes showed magnificent antimicrobial property against Pseudomonas aeruginosa (MTCC 741) which causes nosocomial infections and E. coli (MTCC 1610) which causes intestinal infection.
Bulletin of the Chemical Society of Ethiopia
ABSTRACT. The synthesis of Schiff base compound derived from 2-hydroxy-3-methoxybenzaldehyde and o-phenylenediamine via solvent-assisted mechanochemical synthesis in the presence of a small amount of dimethylformamide as liquid-assisted solvent was reported. The Co(II), Ni(II), Cu(II) and Zn(II) Schiff base complexes were synthesized and characterized by powder x-ray diffraction, infra-red spectroscopy, differential scanning colorimetry, thermogrametric analysis, energy dispersive X-ray analysis and CHNS/O macro-analysis. According to infrared spectral analysis, a strong band in the spectra of Schiff base at 1617 cm-1 was assigned to the azomethine v(C=N) stretching vibration. In the complexes, it shifted to lower frequency regions, indicating the formation of desired compounds. The DSC thermogram of Schiff base showed a single sharp peak at 158 oC, which is attributed to the melting or the phase transition. As revealed by TGA, the complexes were obtained as solid compounds containi...
Antibacterial Co(II), Ni(II), Cu(II) and Zn(II) complexes with biacetyl-derived Schiff bases
Journal of The Serbian Chemical Society, 2010
The condensation reactions of biacetyl with orthohydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML 2 .2H 2 O] where M = Co(II), Ni(II), Cu(II) and Zn(II) and L = HL 1 and HL 2 . These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1 H-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141-160 °C. These compounds were also screened for their in-vitro antibacterial activity against four bacterial species, namely; Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtillis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.