scholarly journals Synthesis Characterization and Biological Activities of Coordination Compounds of 4-Hydroxy-3-nitro-2H-chromen-2-one and Its Aminoethanoic Acid and Pyrrolidine-2-carboxylic Acid Mixed Ligand Complexes

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Temitayo Aiyelabola ◽  
Ezekiel Akinkunmi ◽  
Efere Obuotor ◽  
Idowu Olawuni ◽  
David Isabirye ◽  
...  

Coordination compounds of 4-hydroxy-3-nitro-2H-chromen-2-one and their mixed ligand complexes with aminoethanoic acid and pyrrolidine-2-carboxylic acid were synthesized by the reaction of Cu(II) and Zn(II) salts in molar ratio 1 : 2 for the coumarin complexes and 1 : 1 : 1 for the mixed ligand complexes, in basic media. The compounds formed were characterized using infrared, Uv-vis spectrophotometric analyses, mass spectrometry, magnetic susceptibility measurements, and EDX analyses. It was concluded that 4-hydroxy-3-nitro-2H-chromen-2-one coordinated as a monobasic ligand for all the complexes; it also coordinated via the carbonyl moiety in the case of the Cu(II) mixed ligand complexes. Similarly it was proposed that the amino acids also coordinated in a bidentate fashion via their amino nitrogen and carboxylate oxygen atoms. The synthesized compounds were screened for their antimicrobial and cytotoxic activities. The complexes exhibited marginal antimicrobial activity but good cytotoxic activity.

2020 ◽  
Vol 45 (1) ◽  
pp. 18
Author(s):  
Abidemi Iyewumi Demehin ◽  
Mary Adelaide Oladipo ◽  
Banjo Semire

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.


1984 ◽  
Vol 39 (12) ◽  
pp. 1676-1679 ◽  
Author(s):  
A. A. M. Aly ◽  
M. M. Kamal ◽  
M. S. El Meligy ◽  
A. I. El Said

Mixed ligand complexes of bis(phenyldithiocarbazato)nickel(II) with triphenylphosphane and a number of ditertiary phosphanes have been synthesised. The complexes were characterised on the basis of molar conductance, magnetic moment values, electronic and IR spectra. Out of the five prepared com plexes the mixed ligand complexes with triphenylphosphane and bis(diphenylphosphino) m ethane are paramagnetic, the mixed ligand complexes with bis(diphenylphosphino) ethane, -propane, and -butane are diamagnetic. The complexes were assigned octahedral, square planar or square pyramidal structures. The biological activities of the complexes were also tested.


2021 ◽  
Vol 33 (8) ◽  
pp. 1911-1918
Author(s):  
T.O. Aiyelabola ◽  
E.O. Akinkunmi ◽  
O Osungunna

The coordination compounds of propanedioic acid with cobalt(II), nickel(II) and copper(II) ions were synthesized using metal:ligand 1:2. In addition to this, mixed ligand complexes using the same metal ions with propanedioic acid as the primary ligand and N,N'-dihydroxy-2,3-butanediimine as the secondary ligand were also synthesized using M:L1:L2 (1:1:1) where L1 = propanedioic acid, L2 = N,N'-dihydroxy-2,3-butanediimine and M = Cu(II), Ni(II) and Cu(II). The synthesized compounds were characterized using FTIR, UV-vis, magnetic susceptibility measurement and percentage metal composition. The ligand and its metal complexes were tested for their cytotoxic and antibacterial activities. Results indicated that a dimeric square planar geometry was assumed by the cobalt(II) and nickel(II) propanedioic acid complexes. Octahedral geometry was proposed for both cobalt(II) and copper(II) mixed ligand complexes. A dinuclear square pyramidal geometry was suggested for the copper(II) propanedioic acid complex and square planar/octahedral geometry for the nickel(II) mixed ligand complex. The copper(II) propanedioic acid complex elicited the best cytotoxic activity. On the other hand, the nickel(II) propanedioic acid complex showed the remarkable antimicrobial activity. The compounds exhibited good antimicrobial activity in most of the cases with the exception of the cobalt(II) propanedioic acid complex. It was concluded that coordination of the ligands to the metal ions lowered the toxicity of the ligands. It was further concluded that the antimicrobial activity of the compounds was partly dependent on the synergism/additive effect of the intrinsic therapeutic properties of the metal ion and the ligands within the coordination sphere of the complexes synthesized. And this is also in part a function of the geometry assumed by the complexes.


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