scholarly journals Synthesis, structural elucidation and electrochemical behavior of some oxime-phenylalanine mixed ligand complexes

2021 ◽  
Vol 34 (3) ◽  
pp. 543-556
Author(s):  
U. T. Öztoprak ◽  
S. P. Özkorucuklu ◽  
G. Y. Baştemur ◽  
M. E. Tunçmen ◽  
F. Karipcin

Four new mixed ligand complexes Me(II)/phenylalanine (phe)/HL [HL =4-(4-bromophenyl- aminoisonitrosoacetyl)biphenyl and Me = Co, Ni, Cu, Zn] were synthesized. These complexes are formulated as: [CoL(phe)(H2O)2], [NiL(phe)(H2O)2], [CuL(phe)(H2O)2] and [ZnL(phe)(H2O)2]. All the compounds were characterized by elemental analyses, FT-IR, magnetic susceptibility measurements, TG/DTA and cyclic voltammetry (CV) experiments. IR spectral data confirmed the coordination of the oxime ligand to the metal ions through the oxime and carbonyl oxygen. The geometrical structures of the complexes have been found to be octahedral. The measured molar conductance values of the complexes in DMF are in agreement with the non-electrolytic nature ofthe complexes. The elemental analyses confirm a 1:1:1 [metal:HL:L(phenylalanine)] molar ratio. Thermal behavior of the compound was investigated by thermal gravimetric analysis (TG) and differential thermal analysis (DTA) techniques. All the complexes were transformed into metal oxides after thermal degradation. The electrochemical properties of both ligand and their complexes were analyzed by cyclic voltammetry (CV) using glassy carbon electrode in DMF solution containing 0.1 M TBAP as supporting electrolyte.                     KEY WORDS: Oxime, electrochemical characterization, mixed ligand complexes, amino acid, phenylalanine   Bull. Chem. Soc. Ethiop. 2020, 34(3), 543-556. DOI: https://dx.doi.org/10.4314/bcse.v34i3.10

2021 ◽  
Vol 9 (2) ◽  
pp. 057-064
Author(s):  
Nkeruwem Udo Nyah ◽  
Etiowo George Ukpong ◽  
Okon Effiong Okon ◽  
Ekemini Johnson Obosi

Tetra dentate Schiff base N, N’-bis [2-hydroxyacetophenone] ethylendiamine (OAcPh-en) were formed by the 2:1 molar condensation of 2-hydroxyacetophenone with ethylenediamine. Their Ni(II), Cu(II), Co(II), Mn(II), Fe(II) and Zn(II) diaquo complexes (I) were synthesized. The neutral bidentate ligand derived from benzaldehyde and ethylenediamine or o-phenylenediamine in 1:1 molar ratio in alcoholic solution yield bis[benzylidene] ethylenediamine (Ben-en) or bis [benzylidene] o-phenylinediamine (Ben-opd) (II). Further reaction between (I) and (II) in alcohol yielded mixed ligand complexes. The characterization of these newly synthesized mixed-ligand complexes were done by elemental analysis, magnetic measurements, infrared spectra and uv-visible spectra, thermo gravimetric analysis, anti-microbial studies have also been under taken


2021 ◽  
Vol 25 (7) ◽  
pp. 147-156
Author(s):  
Ajeet Kumar Maurya ◽  
Ashish Kumar Srivastava ◽  
Krishna Srivastava ◽  
Jagdish Prasad

Four mixed-ligand coordination polymer complexes of cobalt(II), copper(II), zinc(II), and cadmium(II) were synthesized by solvothermal method in 1:1:1 metal: 4,4’-bipy: 2,5-pdc molar ratio using 2,5-pyridinedicarboxylic acid (2,5-pdc) and 4,4’-bipyridine (4,4’-bipy). These complexes are viz; 1. [Co2(4,4'-bipy)(2,5-pdc)2(H2O)4]n 2. [Cu2(4,4'-bipy) (2,5-pdc)2]n 3. [Zn2(4,4'-bipy)(2,5-pdc)2(H2O)4]n and 4. [Cd3(4,4'-bipy)(2,5-pdc)2(OOCCH3)2(H2O)4]n.. All these complexes (1-4) have been characterized by elemental analyses (C,H,N), FT-IR-spectra, thermal analyses (TGA/DTA/DTG), fluorescence spectra and powder X-ray diffraction (PXRD) analyses to arrive at conclusion regarding their geometrical structure.


2018 ◽  
Vol 10 (3) ◽  
pp. 291-302
Author(s):  
T. K. Pal ◽  
M. A. Alam ◽  
J. Hossen ◽  
S. Paul ◽  
H. Ahmad ◽  
...  

In this study, new mixed ligand complexes have been prepared from bis(2,4,4-trimethylpentyl)dithiophosphinic acid (C16H35PS2) and 2,9-dimethyl-1,10-phenanthroline (C14H12N2) with various metal(II) ions. The molecular formula of the metal complexes were [Mn(C16H34PS2)(C14H12N2)]Cl (1), [Fe(C16H34PS2)(C14H12N2)]Cl (2), [Co(C16H34PS2) (C14H12N2)]Cl (3), [Zn(C16H34PS2)(C14H12N2)]Cl (4) and [Cd(C16H34PS2)(C14H12N2)]Cl (5). These complexes have been characterized by various physico-chemical techniques such as melting point, molar conductance, magnetic susceptibility measurements as well as UV-Vis, IR, TG and mass spectroscopic analyses. The surface morphology was determined by scanning electron microscope (SEM). The magnetic moment value, color as well as spectral measurements suggested that the geometrical structures of the metal complexes were tetrahedral. The spectral data showed that bis(2,4,4-trimethylpentyl)dithiophosphinic acid and 2,9-dimethyl-1,10-phenanthroline ligands  acted as uninegative and neutral bidentate ligand, respectively. The obtained mixed ligand complexes were more stable in air and highly soluble in common organic solvent. The bio-efficacy of ligands and metal complexes have been screened against the test microorganism using agar disc diffusion method. The complex 4 showed potential antibacterial activity against Sterptococcus aureus as compared to standard drug, imipenem. On the other hand, the complex 3 also displayed more potent antifungal activity against Lecanicillium fungicola. Moreover, the complex 3 was also found to have better scavenging activity against 2,2-diphenyl-1-picrylhydrazyl.


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.


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.


2018 ◽  
Vol 11 (1) ◽  
pp. 32-36
Author(s):  
I.T. Siraj ◽  
M Sule

Complexes of Mn(II), Fe(II) and Co(II) containing N, N’-bis[o-anisaldehyde]p-phenylenediamine tetradentate Schiff base as primary ligand and glycine as secondary bidentate ligand have been synthesized by reflux in 1:1:1 mole ratio and characterized both analytically and spectroscopically. Molar conductance measurement (69.02 to 86.30Ω–1 cm2 mol–1) of the complexes indicated they are weak electrolyte and magnetic susceptibility measurement shows values in range of 4.53 to 5.59BM indicating their paramagnetism. The infrared data suggested that the Schiff base coordinated via the two nitrogen atoms of the azomethine groups (1628 to 1680 cm-1) and the oxygen atoms of the adjacent methoxy groups (1341 to 1389 cm-1), while glycine coordinated via the nitrogen atom of the amino group (3060-3324 cm-1) and the oxygen atom of the carboxylate anion. Based on the analytical and spectroscopic data the complexes may be assigned an octahedral geometries and molecular formulae of the form [M(L)Gly], where M = Mn, Fe and Co, L=Schiff base and Gly = glycine. The Schiff base and its mixed ligand complexes were screened for antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella typhi, Mucor inducus and Aspergillus fumigatus. The complexes exhibited enhanced antimicrobial activity (10mm to 18mm) at 60 µg/disc as compared to 10mm activity of the uncoordinated Schiff base at the same concentration.Keywords: Mixed ligand complex; Schiff base, Glycine, p-phenylenediamine, o-anisaldehyde


2011 ◽  
Vol 8 (1) ◽  
pp. 43-48
Author(s):  
S. A. I. Sharif ◽  
A. N. El-Tajoury ◽  
A. A. Elamari

The mixed ligand complexes of Co(II), Ni(II), Cu(II) and Cd(II) have been synthesized by using 1-phenylazo-2-naphthol as primary ligand and salicylaldehyde as secondary ligand. All the prepared complexes were identified and confirmed by elemental analyses (C, H and N), molar conductance measurements, infrared, electronic absorption and electron paramagnetic resonance. The elemental analysis data suggest that the stoichiometry of the complexes to be 1:1:1[M: L1: L2] ratio. The molar conductance measurements of the complexes indicate their non-electrolytic nature. The infrared spectral data showed the coordination sites of the free ligand with the central metal ion. The electronic absorption spectral data revealed the existence of an octahedral geometry for Co(II) and Cd(II) complexes and a square planar geometry for Ni(II) and Cu(II) complexes. The electron paramagnetic resonance spectra of the Co(II) and Cu(II) complexes showed the existence a paramagnetic phenomenon and supported their geometrical structures which confirmed by the electronic absorption spectra. The ligands and mixed ligand complexes have been tested on antibacterial activity against three strains of pathogenic bacteria such asEscherichia coli, Staphylococcus aureusandPseudomonas aeruginosa


2020 ◽  
pp. 7-16

With the aim of determination of electronic and geometrical structures of mixed-ligand complexes, theoretical modeling of the structures of coordination compounds of transition metals with dialkyldithiophosphate chelating ligands with aminobenzimidazoles carried out using quantum chemical methods. Using BIOVIA Materials Accelrys Studio 2017 software packages, the geometry, electron density distribution, and frontier orbitals calculated for the mixed ligand complexes of Au(III), Pt(II), Ag(I), Cu(II), Ni(II), Fe(III), which are necessary for understanding the electronic structure of coordination compounds with chelating ligands.


2020 ◽  
Vol 36 (6) ◽  
pp. 1225-1228
Author(s):  
Ratnesh Kumar Singh ◽  
Anju Kumari Gupta ◽  
Sachin Prakash ◽  
D. Prakash

Mixed ligand complexes of Al(III) with o-Nitrophenol, 1-Nitroso-2-naphthol, 2,4-Dinitrophenol, 8-Hydroxyquinoline, 2,4,6-Trinitrophenol or o-Nitrobenzoic acid and Ethylenediamine were prepared and studied by elemental analyses, conductometric measurements, FTIR and UV-Vis measurements. These studies indicates the coordination of aluminium metal with o-Nitrophenol, 1-Nitroso-2-naphthol, 2,4-Dinitrophenol, 8-Hydroxyquinoline, 2,4,6-Trinitrophenol or o-Nitrobenzoic acid through oxygen or/and nitrogen atom and with Ethylenediamine through nitrogen atom.


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.


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