scholarly journals Spectral Investigation andIn VitroAntibacterial Evaluation of NiIIand CuIIComplexes of Schiff Base Derived from Amoxicillin andα-Formylthiophene (αft)

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Narendra Kumar Chaudhary ◽  
Parashuram Mishra

Two new metal complexes of general formula M(Haαft)2[M =NiIIandCuII] of asymmetrical Schiff base ligand (HL = Haαft) derived from amoxicillin andα-formylthiophene have been prepared and characterized by various physicochemical and spectral techniques. Molar conductance measurement indicates nonelectrolytic nature of the metal complexes. FT-IR spectral study reveals the ligation of metal ions at two different nitrogen [NN] donor sites of Haαft. FT-IR and electronic absorption spectral evidences suggest distorted tetrahedral and square planar geometry forCuIIandNiIIcomplexes, respectively. The structure optimization by molecular mechanics (MM) force field calculation through ArgusLab 4.0.1 version software also supports the concerned geometry of the complexes. The cell dimensions as suggested by XRPD study,a(6.753 Å),b(13.904 Å),c(20.122 Å),α(142.76°),β(106.580°), andγ(72.4343°) forCuIIanda(24.2547 Å),b(6.6371 Å),c(5.5047 Å) (α=β=γ= 90°) forNiIIcomplexes, are in good agreement with their triclinic and orthorhombic crystal systems. Particle size calculation by Scherrer’s formula indicates nanocrystalline nature of the complexes. The antibacterial sensitivity study suggests promising activities of Haαft (Ligand) and M(Haαft)2complexes against four clinical pathogenic bacteria, namely,E. coli,P. vulgaris,P. aeruginosa, andS. aureus, though being less active than the standard drug amikacin.

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Narendra Kumar Chaudhary ◽  
Parashuram Mishra

A novel Schiff base ligand of type HL was prepared by the condensation of amoxicillin trihydrate and nicotinaldehyde. The metal complexes of Co+2, Ni+2, Cu+2, and Zn+2 were characterized and investigated by physical and spectral techniques, namely, elemental analysis, melting point, conductivity, 1H NMR, IR, UV-Vis spectra, ESR, SEM, and mass spectrometry measurements. They were further analyzed by thermal technique (TGA/DTA) to gain better insight about the thermal stability and kinetic properties of the complexes. Thermal data revealed high thermal stability and nonspontaneous nature of the decomposition steps. The Coats-Redfern method was applied to extract thermodynamic parameters to explain the kinetic behavior. The molar conductance values were relatively low, showing their nonelectrolytic nature. The powder XRD pattern revealed amorphous nature except copper complex (1c) that crystallized in the triclinic crystal system. The EPR study strongly recommends the tetrahedral geometry of 1c. The structure optimization by MM force field calculation through ArgusLab 4.0.1 software program supports the concerned geometry of the complexes. The in vitro antibacterial activity of all the compounds, at their two different concentrations, was screened against four bacterial pathogens, namely, E. coli, P. vulgaris, K. pneumoniae, and S. aureus, and showed better activity compared to parent drug and control drug.


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.


2013 ◽  
Vol 16 (2) ◽  
pp. 109-114
Author(s):  
S. Asha Jebamary ◽  
R. Antony ◽  
S. Theodore David ◽  
K. Karuppasamy ◽  
S. Thanikaikarasan ◽  
...  

Four new Schiff bases have been derived from the condensation of acenapthoquinone and naphthylamines in 1:2 molar ratios. These Schiff base ligands were used to synthesise novel mononuclear Ni(II) complexes with square planar geometry. The ligands and the complexes have been investigated by elemental analyses, spectroscopic methods (FT-IR and UV-Vis.,), molar conductance and magnetic susceptibility studies. The electrochemical properties of Ni(II) complexes have been studied by cyclic voltammetry technique. The catalytic efficacy of the complexes has been analysed in the oxidation of toluene to benzyl alcohol, using H2O2. Biological activities of these ligands and complexes were checked against selected bacterial strains (E. coli and S. Aureus).


2012 ◽  
Vol 9 (3) ◽  
pp. 1113-1121 ◽  
Author(s):  
A. P. Mishra ◽  
A. Tiwari ◽  
S. K. Gupta ◽  
Rajendra Jain

Some new Schiff base metal complexes of Co(II), Ni(II) and Cu(II) derived from 3-chloro-4-fluoroaniline (HL1) and 4-fluoroaniline (HL2) with 2-thiophenecarboxaldehyde have been synthesized and characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR and magnetic susceptibility. The complexes exhibit coordination number 4 or 6. The complexes are colored and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal: ligand) ratio. FAB-mass data show degradation pattern of the complexes. The Schiff base and metal complexes show a good activity against the bacteria;B. subtilis,E. coliandS. aureusand fungiA. niger,A. flavusandC. albicans. The antimicrobial results also indicate that the metal complexes are better antimicrobial agents as compared to the Schiff bases.


2021 ◽  
Vol 33 (6) ◽  
pp. 1222-1228
Author(s):  
R. Selvarani ◽  
S. Balasubramaniyan ◽  
K. Rajasekar ◽  
M. Thairiyaraja ◽  
R. Meenakshi

A new bidentate Schiff base (E)-N′[(E)-3-phenylallylidene]benzene-1,2-diamine derived from the condensation of o-phenylenediamine and cinnamaldehyde and its Mn(II) and Hg(II) complexes were synthesized and characterized by elemental analysis, molar conductance, magnetic moment, electronic spectra, IR, far-IR and NMR (1H & 13C) spectral studies. The elemental analysis and these metal proposed the metal:ligand stoichiometry and molecular formulae of the metal complexes. The molar conductance and electrochemical property indicates monomeric, neutral nature and redox properties of the metal complexes. The UV-visible spectral study supports the octahedral geometry for Mn(II) complex and square planar geometry for Hg(II) complex and further confirmed by magnetic moment. IR spectral data examined the coordination mode but far-IR is useful to identify the metal-ligand vibrations. The geometry, magnetic property and unsymmetrical nature of these metal complexes corroborated by NMR (1H & 13C) spectra. The DFT of Mn(II) complex studied and the structure optimized by B3LYP/Lan L2DZ using Gaussian 09W. Quantum chemical calculations were done by Mullikan population analysis, HOMO-LUMO and molecular electrostatic potential. The in vitro biological screening effects of the investigated complexes were tested against some bacteria and fungus by agar-well diffusion method. The results indicated that Mn(II) and Hg(II) complexes exhibit potentially active than the Schiff base which was further confirmed by pharmacokinetics study. The antioxidant activity of Schiff base and its Mn(II) complex was examined by radical scavenging DPPH method.


2020 ◽  
Vol 18 (1) ◽  
pp. 1304-1315
Author(s):  
Naushad Ahmad ◽  
Manawwer Alam ◽  
Rizwan Wahab ◽  
Mukhtar Ahmed ◽  
Ashfaq Ahmad

AbstractSchiff-base ligand, 2,6-bis(benzimino)-4-phenyl-1,3,5-triazine (L), and its transition metal complexes of Co(ii), Ni(ii), and Cu(ii) were synthesized by refluxing the reaction mixture and its analytical, spectral, and thermogravimetric characteristics were explored by various techniques: AAS, FT-IR, UV-vis, TG-DTG, CHNS/O, and VSM. It was observed that all the metal containing complexes are non-electrolytic, mononuclear, and paramagnetic in nature, confirmed by the molar conductance and magnetic susceptibility measurements. Optical spectral data were used to investigate the geometrical and spectral parameters of [Co(L)(ac)2], [Ni(L)(ac)2], [Cu(L)(ac)2], [Cu(L)(acac)2], and [Cu(L)(fmc)2] complexes. Simultaneous thermal analyses (TG-DTG) in nitrogen atmosphere reveal that the ligand decomposes in one step, [Co(L)(ac)2], [Ni(L)(ac)2], and [Cu(L) (ac)2] complexes are decomposed in three steps, whereas [Cu(L)(acac)2] and [Cu(L) (fmc)2] are decomposed in five and two steps, respectively. In addition, activation energy (Ea) and pre-exponential factor (ln A) were evaluated by TG-DTG decomposition steps of compounds using the Coats–Redfern formula. Enthalpy (∆H), entropy (∆S), and Gibbs free energy (∆G) of the as-prepared metal complexes were also speculated by various thermodynamic equations.


2019 ◽  
Vol 25 (103) ◽  
pp. 68-89
Author(s):  
Hiba Ibrahim Abdulla AL-Joubory ◽  
Khalid Mohamad Motny Al-janaby

This work included synthesis of azo dye (H1) by the reaction of diazonium salt to sulfacetamide with 4-hydroxy benzaldehyde at (0-5) oC  and synthesis of schiff base (H2-H6) through reaction substituted aromatic amine (aniline, 4-nitro aniline, 4-chloro aniline, 4-amino benzoic acid and phenyl hydrazine)  with aldehyde group in azo compound (H1) in ethanol compounds (H2-H6) and tetrazole derivatives prepared by reaction schiff base with sodium azide in ethanol compounds (H7-H11) and characterization by using spectroscopic techniques Uv/Vis, FT-IR, C.H.N. and H1-NMR of some the prepared compounds using DMSO-d6 a solvent, in addition melting point and determination a purity of TLC, and this work consists a study of biological activity for the some prepared compounds against four types of pathogenic bacteria and know to be resistant to anti biotic.


2020 ◽  
Vol 32 (11) ◽  
pp. 2846-2854
Author(s):  
V. Soundaranayaki ◽  
A. Kulandaisamy

Novel tetra dentate Cu(II), Ni(II), Co(II), VO(II) and Zn(II) Schiff base complexes have been synthesized from salicylidene-4-iminoantipyrine and tyrosine. The synthesized Schiff base complexes was characterized by powder X-ray diffraction studies (XRD), scanning electron microscopy (SEM), FT-IR, ESR, 1H NMR, 13C NMR, UV-vis, molar conductance and magnetic susceptibility measurements. The general formula of complexes was confirmed as [ML] type [M = Cu(II), Co(II), Zn(II), Ni(II) and VO(II); L = C27H24N4O4]. Magnetic susceptibility, IR and UV-vis, spectral data showed that all the complexes have square planar geometry except vanadyl complex which suggests square pyramidal geometry. Lower molar conductance values proved that all the chelates were non-electrolytic nature. The X-band ESR spectra of [CuL] and [VOL] complexes in DMSO solution suggest that the complexes were predominant covalent character. Powder XRD and SEM image pattern evidenced that all the compounds were crystalline in nature and their size ranges from 100-40 nm. Calf thymus DNA binding potential of [CuL] and [VOL] complexes shows that the binding occurs through intercalation mode with low binding constant. The analgesic, CNS, antiulcer and antimicrobial activities of the investigated compounds report reveals that the chelates were significant effect than free Schiff base.


2009 ◽  
Vol 6 (3) ◽  
pp. 615-624 ◽  
Author(s):  
K. Siddappa ◽  
K. Mallikarjun ◽  
Tukaram Reddy ◽  
M. Mallikarjun ◽  
C. V. Reddy ◽  
...  

A new complexes of the type ML, MʹL and M″L [where M=Cu(II), Co(II), Ni(II) and Mn(II), Mʹ=Fe(III) and M″=Zn(II), Cd(II) and Hg(II) and L=N1-[(1E)-1-(2-hydroxyphenyl)ethylidene]-2-oxo-2H-chromene- 3-carbohydrazide (HL)] Schiff base have been synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductance, IR,1H NMR, UV-Visible and ESR data. The studies indicate the HL acts as doubly monodentate bridge for metal ions and form mononuclear complexes. The complexes Ni(II), Co(II), Cu(II) Mn(II) and Fe(III) complexes are found to be octahedral, where as Zn(II), Cd(II) and Hg(II) complexes are four coordinated with tetrahedral geometry. The synthesized ligand and its metal complexes were screened for their antimicrobial activity.


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.


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