Studies on mixed ligand complexes of ruthenium(II) chiral Schiff bases with nitrogen donors

Polyhedron ◽  
1993 ◽  
Vol 12 (19) ◽  
pp. 2395-2401 ◽  
Author(s):  
R.I. Kureshy ◽  
N.H. Khan
Keyword(s):  
Schiff Bases ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Nitrogen Donors

f-f spectral studies of holmium(III) complexes

1983 ◽  
Vol 36 (4) ◽  
pp. 695 ◽  
Author(s):  
K Iftikhar ◽  
N Ahmad
Keyword(s):  
Coordination Number ◽  
Oscillator Strength ◽  
Magnetic Moment ◽  
Visible Region ◽  
Mixed Ligand ◽  
Oscillator Strengths ◽  
Mixed Ligand Complexes ◽  
Spectral Studies ◽  
Nitrogen Donors ◽  
Covalency Parameters

Holmium(III) mixed-ligand complexes containing ligands having oxygen and nitrogen donors have been spectrophotometrically investigated. The observed spectra in the visible region have been analysed to calculate covalency parameters (β, b� and δ), oscillator strengths and Judd-Ofelt parameters. The degree of covalency in the complexes increases with increase in coordination number. The hypersensitivity is correlated with the degree of covalency and number of coordinated ligands. The higher values of covalency parameters, oscillator strength and magnetic moment in the ten-coordinate HoIII is taken as evidence of participation of f-orbitals in bonding.

scholarly journals Synthesis, Characterization and Antimicrobial Activity of Mixed Schiff Base Ligand Complexes of Co(II), Ni(II), Cu(II) and Zn(II)

2011 ◽  
Vol 8 (3) ◽  
pp. 1258-1263 ◽  
Author(s):  
A. K. Mapari ◽  
M. S. Hate ◽  
K. V. Mangaonkar
Keyword(s):  
Antimicrobial Activity ◽  
Thermogravimetric Analysis ◽  
Schiff Bases ◽  
Free Ligand ◽  
Antimicrobial Activities ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Azomethine Nitrogen ◽  
Diffusion Method ◽  
Spectral Studies

The mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with Schiff basesN-(2-hydroxy-1-naphthylidene)-4-methylaniline (L1H) andN-(2-hydroxybenzylidene)-2,3-dimethylaniline (L2H) have been synthesized and characterized. The resulting complexes were characterized by elemental analysis, thermogravimetric analysis, magnetic moment measurements, conductivity measurements,1H NMR, IR, UV-visible and ESR spectral studies. The Schiff bases acts as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The complexes are non-electrolytic in DMSO. The presence of the two coordinated water molecules in these complexes was indicated by IR spectra and thermogravimetric analysis of the complexes. From the analytical and spectral data the stoichiometry of these complexes have been found to be [M(L1)(L2)(H2O)2] {where M = Co(II) , Ni(II), Cu(II) and Zn(II)}. It is found that Co(II), Ni(II), Cu(II) and Zn(II) complexes exhibited octahedral geometry. The antimicrobial activities of ligands and their mixed ligand complexes were screened by disc diffusion method. It is found that the metal complexes have higher antimicrobial activity than the free ligand.

scholarly journals Synthesis, spectroscopic, biological activities and DFT calculations of nickel(II) mixed-ligand complexes of tridentate Schiff bases

2020 ◽  
Vol 45 (1) ◽  
pp. 18
Author(s):  
Abidemi Iyewumi Demehin ◽  
Mary Adelaide Oladipo ◽  
Banjo Semire
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Elemental Analysis ◽  
Biological Activities ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Molar Ratio ◽  
Azomethine Nitrogen ◽  
Elemental Analysis Data ◽  
Biological Studies

Ni(II) mixed-ligand complexes of [NiLNH3] (where L= N-salicylidene-o-aminophenol (L1), N-(5-methoxysalicylidene-o-aminophenol) (L2) and N-(2-hydroxy-1-naphthalidene)-o-aminophenol) (L3) containing ONO tridentate Schiff bases and ammonia were synthesized and characterized by elemental analysis, infrared, ultraviolet-visible, proton and carbon-13 spectroscopies. Theoretical calculations were also performed on the optimized structures of the Ni(II) mixed-ligand complexes. The Infrared and ultraviolet-visible spectra of the complexes were calculated, and the results compared with the corresponding experimental spectra to augment the experimental structural identification. The elemental analysis data confirmed the formation of 1:1:1 [metal: Schiff base: ammonia] molar ratio. The NMR spectra showed that the Schiff bases coordinated to the Ni(II) ion via the two deprotonated phenolic oxygen and azomethine nitrogen atoms. The biological studies showed that the complexes exhibited higher antibacterial and antioxidant activities than the free Schiff base ligands.

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