Synthesis, Spectroscopic and Antimicrobial properties of Co(II), Ni (II) and Cu(II) complexes of (E)-N’-(2-hydroxy -5-nitrobenzylidene)isonicotinohydrazide) (original) (raw)
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Asian Journal of Chemical Sciences, 2019
Two complexes of Cu(II) and Ni(II) with the ligand N- (4-methoxybenzylidene) isonicotinohydrazide, having the formula [M(La)2]2+ (M = Cu(II) and Ni(II)) were synthesized. The ligand was synthesized by the condensation of isonicotinic acid hydrazide (isoniazid) with 4- methoxybenzaldehyde (p- anisaldehyde). The complexes were characterized by FTIR, UV-Vis spectroscopy, molar conductivity, magnetic susceptibility and evaluated for their in vitro antibacterial activity against human pathogens like gram negative Escherichia coli (E. coli) and gram positive Bacillus cereus (B. cereus)strains. The results indicate that all complexes consist of N and O coordination with metals has better antimicrobial activity.
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.
Ife Journal of Science, 2016
A series of Schiff base ligands ( L 1 -L 4 ) prepared by condensation of isonicotinic acid hydrazide with substituted benzaldehydes and their corresponding copper(II) complexes ( L 1 A-L 4 A ) had been synthesized and characterized based on IR, 1 H NMR and electronic absorption spectroscopy as well as by molar conductivity and elemental analyses. The in-vitro antimicrobial activity of the compounds against Staphylococcus aureus , Enterococcus feacalis , Escherichia coli and Pseudomonas aeruginosa studied using agar ditch method indicated that the copper complexes exhibited higher activity than the corresponding ligands. The antimicrobial activity of both the ligands and complexes was dependent on the electronic effect of the halogen substituent, which decreased in the order F > Cl > Br. Keywords: N -(4-substitutedbenzylidene) isonicotinohydrazide, Halogen Schiff Bases, Copper (II) Complexes, Antimicrobial Activity
Arabian Journal of Chemistry, 2017
Co(II), Ni(II), Cu(II) and Zn(II) complexes of bidentate Schiff bases derived from the condensation of 4-amino-5-mercapto-3-methyl/ethyl-1,2,4-triazole with 5-nitrofurfuraldehyde were synthesized and tested as antimicrobial agents. The Schiff bases and their metal complexes were characterized by elemental analyses, magnetic moment measurements, spectroscopic (IR, Electronic, 1 H NMR, ESR) and thermogravimetric analyses. A square planar geometry for Cu(II) and octahedral geometry for Co(II), Ni(II) and Zn(II) complexes have been proposed. The presence of coordinated water in metal complexes was confirmed by thermal and IR data of the complexes. The Schiff bases and their metal complexes have been screened for antibacterial [Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, Staphylococcus aureus] and antifungal activities [Aspergillus niger, A. flavus].
American Journal of Applied Chemistry, 2018
A Schiff base (SB) is derived from salicylaldehyde and 2-aminopyridine. The transition metal complexes of N i(II), Cu (II), Co and Cd (II) metal ions were prepared with this Schiff base (SB), which were used as ligand. Several physical tools, in particular; elemental analysis, molar conductivity, magnetic susceptibility, infrared spectroscopy (IR), electronic absorption spectroscopy (ESR) to investigate the chemical structure of the prepared transition metal complexes. The elemental analysis data shows the formation of 1:2 [M:2L] complex of the formula of M 2+ L 2 , where M 2+ =Ni(II), Cu(II), Co(II), Cd(II) and L = Schiff base (SB). The molar conductance (conductivity) measurements were revealed that all the complexes are nonelectrolyte in nature. The infrared (IR) spectral studies indicated the binding sites of the Schiff base ligand with the transition metal ions. The magnetic susceptibility measurements and electronic spectral results supported the predicted coordination geometry of the complexes and magnetic properties (para or dia-magnetic nature) of the complexes. The Ni(II), Cu(II), Co(II) ion forms high spin tetrahedral geometry, whereas Cd(II) ion forms low spin tetrahedral structure. The free Schiff base and its complexes have been tested for their antimicrobial activities against four human pathogenic (two gram-positive and two gramnegative) bacteria. The obtained results showed that only Cu(II) complex exhibited strong activity toward human pathogenic gram positive and gram negative bacteria whereas the Ni(II), Co(II) and Cd(II) complexes showed week to moderate antimicrobial activity compared with standard Kanamycin and Ampicillin.
Synthesis, Characterization and Antimicrobial Activity of Metal Complexes of Schiff’s Base.pdf
Structural modification of organic molecule has considerable biological relevance. Further, coordination of a biomolecules to the metal ions significantly alters the effectiveness of the biomolecules. In view of the antimicrobial activity a series of nickel, copper and zinc complexes of tridentate Schiff base derived from the condensation reaction of S-benzyldithiocarbazate with 2- hydroxyacetophenone have been synthesized and found to be potential antimicrobial agents. An attempt is also made to correlate the biological activities with geometry of the complexes. The complexes have been characterized by molar conductance, magnetic susceptibility, IR and electronic spectroscopic techniques.
European Journal of Medicinal Chemistry, 2012
Two new Schiff bases of 1,3-diphenyl-1H-pyrazole-4-carboxaldehyde and 4-amino-5-mercapto-3methyl/H-1,2,4-triazole [HL 1e2 ] and their Cobalt, Nickel, Copper and Zinc complexes have been synthesized and characterized by elemental analyses, spectral (UVevis, IR, 1 H NMR, Fluorescence) studies, thermal techniques and magnetic measurements. A square planar geometry for Cu(II) and octahedral geometry for Co(II), Ni(II) and Zn(II) complexes have been proposed. In order to evaluate the biological activity of Schiff bases and to assess the role of metal ion on biological activity, the pyrazole Schiff bases and their metal complexes have been studied in vitro antibacterial against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and antifungal against Aspergillus niger, and Aspergillus flavus. In most of the cases higher activity was exhibited upon coordination with metal ions.