scholarly journals Synthesis and Characterization of new Schiff base Ligand type [N4O4] from 3-(Ethoxymethylene)pentane-2.4-dione and its Niп Complex

2019 ◽  
Vol 7 (1) ◽  
pp. 40
Author(s):  
Eman I. Alsalihi

The Schiff base reaction plays an important role in the condensation reaction between 3-(ethoxymethylene) pentane- 2.4-dione and 3,3’-diaminobenzidine in the presence of calculated amounts of KOH as a catalyst. This reaction has been carried out in the ethanol under reflux and overnight stirring condition. All syntheses were carried out under an atmosphere of hydrogen forming a new ligand [3,3’,3’’,3’’’-(1E,1’E,1’’E,1’’’E)-(biphenyl-3,3’,4,4’-tetrayltetrakis (azan-1-yl-1-ylidene)) tetrakis (methan-1- yl-1-ylidene) tetrakis (4-methoxybut-3-en-2-one)] type [N4O4]. The ligand and its Niп complex of the general formula [Ni2(L)] have been characterized by spectroscopic methods (Fourier transform infrared and ultraviolet-visible), elemental analysis (C.H.N), metal content, magnetic susceptibility measurement, thin-layer chromatography, mass spectrometry, X-ray powder diffraction powder diffraction, 1H-nuclear magnetic resonance, molar conductance, and biological activity. The ligand and its Ni complex were exposed to two types of bacteria (Staphylococcus aureus and Bacillus subtilis), using the agar disc diffusion method, and the ligand and its Niп complex exhibited significant activities against these two types of bacteria. Our study revealed the formation of a new ligand type [N4O4] and four-coordinate tetrahedral structure around Niп metal ion with the ratio of 1:2 (ligand:metal) stable compounds which can be used in many fields, such as medicine and industry.

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
F. K. Ommenya ◽  
E. A. Nyawade ◽  
D. M. Andala ◽  
J. Kinyua

A new series of Mn (II), Co (II), Ni (II), Cu (II), and Zn (II) complexes of the Schiff base ligand, 4-chloro-2-{(E)-[(4-fluorophenyl)imino]methyl}phenol (C13H9ClFNO), was synthesized in a methanolic medium. The Schiff base was derived from the condensation reaction of 5-chlorosalicylaldehyde and 4-fluoroaniline at room temperature. Elemental analysis, FT-IR, UV-Vis, and NMR spectral data, molar conductance measurements, and melting points were used to characterize the Schiff base and the metal complexes. From the elemental analysis data, the metal complexes formed had the general formulae [M(L)2(H2O)2], where L = Schiff base ligand (C13H9ClFNO) and M = Mn, Co, Ni, Cu, and Zn. On the basis of FT-IR, electronic spectra, and NMR data, “O” and “N” donor atoms of the Schiff base ligand participated in coordination with the metal (II) ions, and thus, a six coordinated octahedral geometry for all these complexes was proposed. Molar conductance studies on the complexes indicated they were nonelectrolytic in nature. The Schiff base ligand and its metal (II) complexes were tested in vitro to evaluate their bactericidal activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus subtilis and Staphylococcus typhi) using the disc diffusion method. The antibacterial evaluation results revealed that the metal (II) complexes exhibited higher antibacterial activity than the free Schiff base ligand.


2012 ◽  
Vol 9 (3) ◽  
pp. 532-540 ◽  
Author(s):  
Baghdad Science Journal

Two Schiff base ligands L1 and L2 have been obtained by condensation of salicylaldehyde respectively with leucylalanine and glycylglycine then their complexes with Zn(II)were prepared and characterized by elemental analyses , conductivity measurement , IR and UV-Vis .The molar conductance measurement indicated that the Zn(II) complexes are 1:1 non-electrolytes. The IR data demonstrated that the tetradentate binding of the ligands L1 and L2 . The in vitro biological screening effect of the investigated compounds have been tested against the bacterial species Staphlococcus aureus, Escherichia coil , Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa by the disc diffusion method . A comparative study of inhibition values of the Schiff base ligands and their complexes indicated that the complexes exhibit higher antimicrobial activity than the free ligands . Zinc ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium .


INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (06) ◽  
pp. 20-29
Author(s):  
S Shukla ◽  
◽  
S. Gautam ◽  
S Chandra ◽  
A. Kumar

A string of novel coordination compounds of Cr(III) complexes have been derived and characterized from the macrocyclic ligands (L 1 -L 2 ) carried out by condensation reaction between ligands and the subsequent metal salt. The chemical composition of ligand was determined by analytical and spectral techniques i.e. elemental analysis, IR and Mass spectrocopy. Spectral techniques revealed tetradentate [N 4 ] the nature of ligand and its coordination mode to metal ion through nitrogen donor atoms. Metal complexes were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, IR, electronic spectra, ePR studies. The geometry of these complexes was ascertained by molecular modelling study by using Gaussian 09 program. All metal complexes were found to exhibit octahedral geometry around the metal ion. The newly synthesized macrocyclic ligands and metal complexes were subjected for antimicrobial screening to determine the inhibition and control against tested microorganisms, bacteria ( S.lutea , S.aureus, S.albus and E.coli ) and fungi ( A.fulviceps, U . hordei, A. niger and P.catinus ) by using disc diffusion method and agar plate technique, respectively. The experimental results suggest that metal complexes exhibit enhanced inhibition zone than free macrocyclic ligand.


Author(s):  
VAIRALAKSHMI M ◽  
PRINCESS R ◽  
JOHNSON RAJA S

Objectives: The aim of our work was to synthesize novel mixed ligand-metal complexes and evaluation of antimicrobial, antioxidant assay, and analysis of catalytic oxidation of cyclohexane. Methods: The complexes were characterized by means of various physicochemical techniques such as elemental analysis, molar conductance, magnetic susceptibility, infrared (IR), electronic absorption, 1H NMR (proton magnetic resonance), and mass spectral studies. The antimicrobial screening study was done by disc diffusion method. The catalytic activity of the complexes was observed in the oxidation of cyclohexane using eco-friendly hydrogen peroxide as oxidant. Results: On comparing the 1H NMR and IR spectral data of free ligand and its complexes, it was found to be azomethine (CH=N) proton which is formed in the free ligand. During complexation, the azomethine proton is coordinated to the metal ion and the phenolic oxygen is coordinated to the metal ion by deprotonation. The analytical data and mass spectra of the ligand and the complexes confirm the stoichiometry of metal complexes as being of the (MLY)Cl type and the metal to ligand ratio is 1:1. The antimicrobial, antioxidant, and catalytic potential were evaluated and the result shows the better activity of the complexes than the ligand. Conclusion: It was found to be copper(II) and zinc(II) complexes which are effective against all the bacteria when compared to standard drug streptomycin. Copper(II) complex was found to be effective antibacterial agent against Aspergillus niger and Aspergillus flavus in comparison to the standard drug Nystatin. The zinc complex exhibited good catalytic activity.


2013 ◽  
Vol 41 (1) ◽  
pp. 126 ◽  
Author(s):  
Hossam S. EL-BELTAGI ◽  
Mona H. BADAWI

The widespread use of medicinal plants for health purposes has increased dramatically due to their great importance to the public health. In this study levels of phenolic, flavonoid contents of Ginkgo biloba and Rosmarinus officinalis from Egypt were determined. HPLC was used to identify and quantify the phenolic compounds in selected plants. The plant extracts were evaluated for their antioxidant activities using various antioxidant methodologies, (i) scavenging of free radicals using 2, 2-diphenyl-1-picrylhydrazyl, (ii) metal ion chelating capacity, and (iii) scavenging of superoxide anion radical. The antimicrobial activity of both plant’s extracts were evaluated against a panel of microorganisms by using agar disc diffusion method. The total phenolic content (75.30 and 98.31 mg/g dry weight in G. biloba and R. officinalis, respectively) was significantly (p<0.05) different. Among the identified phenolic compounds, quercetin, kaempferol and caffeic acid were the predominant phenolic compounds in Ginkgo biloba, whereas carnosic acid, rosmarinic acid, narinigen and hispidulin were the predominant phenolic compound in Rosmarinus officinalis leaves. The antioxidant activity increased with the concentration increase. The R. officinalis was more active than G. biloba extract against Gram-negative bacteria. This study reveals that the consumption of these plants would exert several beneficial effects by virtue of their antioxidant and antimicrobial activities.


Author(s):  
Haruna, A. ◽  
Rumah, M.M. ◽  
Sani, U. ◽  
Ibrahim, A.K.

Schiff base derived from the reaction of 2-amino phenol and 2-hydroxy-1-naphthaldehyde and its Co (II), and Mn (II) complexes have been synthesized and characterized by solubility test, melting point/ decomposition temperatures, molar conductance, IR and magnetic susceptibility. The number of ligands coordinated to the metal ion was determined using Job’s method of continuous variation. Their molar conductance values indicate that all the complexes are non-electrolytes. Magnetic moment values of the complexes showed that both Mn (II) and Co (II) are paramagnetic. The spectroscopic data of metal complexes indicated that the metal ions are complexed with azomethine nitrogen and deprotonated oxygen atom. Corrosion inhibition of the schiff base and Mn (II) and Co (II) complexes were evaluated using the weight loss method in a 0.1MHCl solution for copper metal. The inhibition efficiency increased with increasing inhibitors concentration. The negative values of Gibb’s free energy of adsorption (ΔGads) confirmed the spontaneity and physical adsorption of the inhibition process which is inconsistent with Langmuir adsorption isotherm.


2020 ◽  
Vol 13 (2) ◽  
pp. 1-8
Author(s):  
R.K. Sree Devi ◽  
S. SudhaKumari

Transition metal complexes of Cu(II), Ni(II), Co(II) with a Schiff base Ligand (R,Z)-2-(2-hydroxy-3-methoxybenzylideneamino)-5-guanidinopentanoic acid (HMA-GPA) was synthesized by the condensation of 2-hydroxy-3-methoxybenzaldehyde and L- Arginine. These were characterized by elemental analysis IR, UV, magnetic susceptibility and molar conductivity measurements. The IR spectra of the Ligand HMA-GPA and the metal complexes suggest that the Ligand coordinates the metal ion through azomethine nitrogen, carboxylate Oxygen and Oxygen of the phenolic -OH group. The electronic absorption spectra and magnetic data indicate the Cu(II), Ni(II)complexes to be square planar and Co(II) complex to be octahedral. The metal complexes and the ligand were subjected to antimicrobial studies by Kirby Bayer Disc-diffusion method and found to have significant activity against the selected bacterial and fungal strains under study.


Author(s):  
RAMALINGAM KUNDENAPALLY ◽  
RAMESH DOMALA ◽  
SREENIVASULU BATHULA

Objectives: Nowadays, antimicrobial resistance represents one of the most significant challenges in the medical community. To overcome the problem, it requires the discovery of newer safe and effective molecules against infectious sickness. Synthesis and screening of 1,8-naphthyridines have attracted much attention over the decades since it plays a key role against the microorganisms. Methods: 1,8-naphthyridine based 5-arylidene derivatives of thiazolidinone (3a-i) has been achieved by the cyclization reaction of 2-chloro-N- (2-phenyl-1,8-naphthyridin-3-yl)acetamide (1) with potassium thiocyanate in acetone followed by its Knoevenagel condensation reaction with appropriate arylaldehydes in ethanol. All the resulting products were confirmed using spectral and physicochemical data. Antibacterial activity was performed against different bacterial strains by agar disc diffusion method using ciprofloxacin as standard. Results: Compound 3b showed tremendous antibacterial activity among all the tested compounds. Conclusions: This study provides several advantages such as shorter reaction times, clean product, and good yields. Most of the final products possessed moderate to excellent antibacterial activity.


2012 ◽  
Vol 9 (3) ◽  
pp. 1543-1549
Author(s):  
Eman Turky Shamkhy ◽  
Isam Hussain T. Al-Karkhi

A novel Schiff base 2-{(E)-[(2,4-dichlorophenyl)imino]methyl}phenol (LB) was synthesized from the condensation reaction of 2,4-dichloroaniline with salicyladehyde in [1:1] ratio in the presence of glacial acetic acid as catalyst. Complexation reaction of this Schiff base with copper (II), cobalt (II) as nitrate salts and with Rhodium (III) as chloride salt to produce three coordinate metal complexes, with a Schiff base: Metal ion ratio of 2:1. These compounds have been characterized by a variety of physico-chemical and spectroscopic techniques. The ligand and its metal complexes were expected to show an interesting bioactivity and cytotoxicity.


2020 ◽  
Vol 36 (05) ◽  
pp. 954-957
Author(s):  
Shivani Prakash ◽  
Anju Kumari Gupta ◽  
Sachin Prakash ◽  
D. Prakash

A series of new hetero binuclear complexes of copper(II) and lead(II) using Schiff base have been synthesized. The Schiff base has been derived from the condensation reaction between Salicylaldehyde and 1,2-Ethylenediamine. The hetero binuclear complexes have been characterized by using elemental analysis, molar conductance measurement, magnetic susceptibility studies, UV-Vis and IR spectra. The studies revealed square planar geometry for the complexes with coordination number four.


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