Metal Complexes of a Novel Schiff Base Based on Penicillin: Characterization, Molecular Modeling, and Antibacterial Activity Study

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.

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Synthesis, Characterization and Antimicrobial Studies of N1-[(1E)-1-(2-Hydroxyphenyl) ethylidene]-2-oxo-2H-chromene-3-carbohydrazide and its Metal Complexes

E-Journal of Chemistry ◽

10.1155/2009/416836 ◽

2009 ◽

Vol 6 (3) ◽

pp. 615-624 ◽

Cited By ~ 2

Author(s):

K. Siddappa ◽

K. Mallikarjun ◽

Tukaram Reddy ◽

M. Mallikarjun ◽

C. V. Reddy ◽

...

Keyword(s):

Antimicrobial Activity ◽

Magnetic Susceptibility ◽

Schiff Base ◽

Metal Complexes ◽

Molar Conductance ◽

Tetrahedral Geometry ◽

H Nmr ◽

Antimicrobial Studies ◽

Mononuclear Complexes ◽

Uv Visible

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.

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Synthesis and antibacterial activity of some Schiff base complexes

Journal of the Serbian Chemical Society ◽

10.2298/jsc0607733n ◽

2006 ◽

Vol 71 (7) ◽

pp. 733-744 ◽

Cited By ~ 42

Author(s):

R. Nair ◽

A. Shah ◽

S. Baluja ◽

S. Chanda

Keyword(s):

Antibacterial Activity ◽

Schiff Base ◽

Metal Complexes ◽

Schiff Bases ◽

Schiff Base Complexes ◽

Ethyl Benzene ◽

Resistant Bacteria ◽

Bacterial Strains ◽

Iron And Zinc

Two Schiff bases were synthesized from raceacetophenone: 1) ADS1 4-ethyl-6-{(E)-1-[(3-nitrophenyl)imino]ethyl}benzene-1,3-diol and 2) ADS3 4-ethyl-6-[(E)-1-{(2-nitrophenyl)imino]ethyl}benzene-1,3-diol. Then their metal complexes were formed. The metals selected for the preparation of complexes were copper, nickel, iron and zinc. Hence, in total 8 metal complexes were synthesized and screened for antibacterial activity against some clinically important bacteria, such as Pseudomonas aeruginosa, Proteus vulgaris, Proteus mirabilis, Klebsiella pneumoniae and Staphylococcus aureus. The in vitro antibacterial activity was determined by the Agar Ditch technique using DMF (polar) and 1,4-dioxane (non polar) as solvents. The Schiff bases showed greater activity than theirmetal complexes; themetal complexes showed differential effects on the bacterial strains investigated and the solvent used, suggesting that the antibacterial activity is dependent on the molecular structure of the compound, the solvent used and the bacterial strain under consideration. The Schiff base ADS3 in the polar solvent DMF showed better antibacterial activity towards the investigated bacterial strains. Amongst the four metals, Zn showed the best antibacterial activity followed by Fe in 1,4-dioxane while Ni followed by Zn and Fe showed the best antibacterial activity in DMF. P. vulgaris was the most resistant bacteria.

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Synthesis, Characterization and Antibacterial Activity of Schiff Base, 4-Chloro-2-{(E)-[(4-Fluorophenyl)imino]methyl}phenol Metal (II) Complexes

Journal of Chemistry ◽

10.1155/2020/1745236 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

F. K. Ommenya ◽

E. A. Nyawade ◽

D. M. Andala ◽

J. Kinyua

Keyword(s):

Antibacterial Activity ◽

Schiff Base ◽

Metal Complexes ◽

Elemental Analysis ◽

Schiff Base Ligand ◽

Condensation Reaction ◽

Molar Conductance ◽

Diffusion Method ◽

Elemental Analysis Data ◽

Ft Ir

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.

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Synthesis and Characterization of New Lead(II) and Organotin(IV) Complexes of Schiff Bases Derived from Histidine and Methionine

International Journal of Inorganic Chemistry ◽

10.1155/2012/568797 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

Har Lal Singh ◽

J. B. Singh

Keyword(s):

Schiff Base ◽

Metal Complexes ◽

Analytical Data ◽

Molar Conductance ◽

Molar Ratio ◽

Azomethine Nitrogen ◽

Spectral Studies ◽

Tetrahedral Geometry ◽

H Nmr ◽

Carboxylate Oxygen

New Schiff base (HL) ligand is prepared via condensation of isatins and amino acids in 1:1 molar ratio. Metal complexes are prepared and characterized by elemental analysis, molar conductance, electronic, infrared, and multinuclear magnetic resonance (1H NMR, 13C NMR, and 119Sn NMR). The analytical data showed that the ligand acts as bidentate toward metal ions via azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of metal : ligand (1 : 2) to from metal complexes (Pb(II)(L)2 and Bu2Sn(L)2, where L is the Schiff base ligands of histidine and methionine). The conductivity values between 15 and 25 Ω−1cm2 mol−1 in DMF imply the presence of nonelectrolyte species. On the basis of the above spectral studies, distorted octahedral and tetrahedral geometry have been proposed for the resulting organotin(IV) and lead(II) complexes.

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Antibacterial Co(II), Ni(II), Cu(II) and Zn(II) complexes with biacetyl-derived Schiff bases

Journal of the Serbian Chemical Society ◽

10.2298/jsc091026098i ◽

2010 ◽

Vol 75 (8) ◽

pp. 1075-1084 ◽

Cited By ~ 13

Author(s):

Muhammad Imran ◽

Mitu Liviu ◽

Shoomaila Latif ◽

Zaid Mahmood ◽

Imtiaz Naimat ◽

...

Keyword(s):

Antibacterial Activity ◽

Schiff Base ◽

Metal Complexes ◽

Schiff Bases ◽

Bacterial Species ◽

Electronic Spectroscopy ◽

Salmonella Typhi ◽

Schiff Base Ligands ◽

No Donor

The condensation reactions of biacetyl with orthohydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML2.2H2O] where M = Co(II), Ni(II), Cu(II) and Zn(II) and L = HL1 and HL2. These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1H-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141-160 ?C. These compounds were also screened for their in-vitro antibacterial activity against four bacterial species, namely; Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtillis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.

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Synthesis, Thermal Characterization and in vitro Antibacterial Assessment of Co(II) and Cd(II) Complexes of Schiff Base Derived from Amoxicillin and Thiophene-2-carbaldehyde

Asian Journal of Chemistry ◽

10.14233/ajchem.2019.21882 ◽

2019 ◽

Vol 31 (4) ◽

pp. 951-959 ◽

Cited By ~ 1

Author(s):

N.K. Chaudhary ◽

B. Guragain

Keyword(s):

Metal Complexes ◽

Biological Activities ◽

Geometry Optimization ◽

Thermal Characterization ◽

Molar Conductance ◽

Sem Analysis ◽

Biological Data ◽

Spectral Studies ◽

Tetrahedral Geometry

A novel AMXTC2 ligand was prepared by simultaneous stirring and refluxing of an equimolar mixture of amoxicillin and thiophene-2-carbaldehyde in methanol and was further used to synthesize metal complexes by metalation with cobalt and cadmium salts, taking ligand metal ratio 2:1. They were characterized by elemental microanalysis, FT-IR, mass, UV-visible, 1H NMR, thermal analysis, magnetic moment and molar conductance measurements. The coordination sites in the ligand were verified by their comparative and extensive spectral studies. The detailed exploration of the data suggested octahedral geometry for Co-AMXTC2 and tetrahedral geometry for Cd-AMXTC2 complexes. The thermodynamic and kinetic parameters such as E*, ΔH*, ΔS* and ΔG* of various decomposition steps were calculated from TGA curves using the Coats-Redfern method. The molar conductivity data suggested non-electrolytic nature of the complexes. SEM analysis was done to observe their surface morphology. The geometry optimization of the proposed molecular structure of the complexes was achieved by running MM2 calculation in Gaussian supported Cs-ChemOffice Ultra-11 program software. The biological activities had been evaluated in vitro against E. coli, K. pneumonia, P. vulgaris and S. aureus pathogens in order to assess their antibacterial potency. The biological data revealed better growth inhibitory action of the ligand and metal complexes with bacterial pathogens.

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

Journal of Chemistry ◽

10.1155/2015/136285 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 3

Author(s):

Narendra Kumar Chaudhary ◽

Parashuram Mishra

Keyword(s):

Schiff Base ◽

Metal Complexes ◽

Pathogenic Bacteria ◽

Sensitivity Study ◽

Molar Conductance ◽

Planar Geometry ◽

Field Calculation ◽

Orthorhombic Crystal ◽

Standard Drug ◽

Ft Ir

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.

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Metal (II) Complexes Derived from Naphthofuran-2-carbohydrazide and Diacetylmonoxime Schiff Base: Synthesis, Spectroscopic, Electrochemical, and Biological Investigation

Bioinorganic Chemistry and Applications ◽

10.1155/2014/942162 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 12

Author(s):

R. B. Sumathi ◽

M. B. Halli

Keyword(s):

Schiff Base ◽

Metal Complexes ◽

Thermal Studies ◽

Analytical Data ◽

Molar Conductance ◽

Tetrahedral Geometry ◽

Biological Investigation ◽

Antibacterial And Antifungal Activities ◽

Antibacterial And Antifungal ◽

Chloride Salts

A new Schiff base and a new series of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) complexes were synthesized by the condensation of naphthofuran-2-carbohydrazide and diacetylmonoxime. Metal complexes of the Schiff base were prepared from their chloride salts of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) in ethanol. The ligand along with its metal complexes have been characterized on the basis of analytical data, IR, electronic, mass,1HNMR, ESR spectral data, thermal studies, magnetic susceptibility, and molar conductance measurements. The nonelectrolytic behaviour of the complexes was assessed from the measured low conductance data. The elemental analysis of the complexes confirm the stoichiometry of the type CuL2Cl2and MLCl2where M = Ni(II), Co(II), Cd(II), and Hg(II) and L = Schiff base. The redox property of the Cu(II) complex was investigated by electrochemical method using cyclic voltammetry. In the light of these results, Co(II), Ni(II), and Cu(II) complexes are assigned octahedral geometry, Cd(II), and Hg(II) complexes tetrahedral geometry. In order to evaluate the effect of metal ions upon chelation, both the ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleaving capacity of all the complexes was analysed by agarose gel electrophoresis method.

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Transition Metal(II) Complexes with Cefotaxime-Derived Schiff Base: Synthesis, Characterization, and Antimicrobial Studies

Bioinorganic Chemistry and Applications ◽

10.1155/2014/926287 ◽

2014 ◽

Vol 2014 ◽

pp. 1-17 ◽

Cited By ~ 11

Author(s):

Aurora Reiss ◽

Mariana Carmen Chifiriuc ◽

Emilia Amzoiu ◽

Cezar Ionuţ Spînu

Keyword(s):

Antibacterial Activity ◽

Schiff Base ◽

Schiff Base Ligand ◽

Magnetic Measurements ◽

Magnetic Moments ◽

Chemical Properties ◽

Molar Conductance ◽

Bacterial Strains ◽

Vis Spectroscopy

New [ML2(H2O)2] complexes, where M = Co(II), Ni(II), Cu(II), and Zn(II) while L corresponds to the Schiff base ligand, were synthesized by condensation of cefotaxime with salicylaldehydein situin the presence of divalent metal salts in ethanolic medium. The complexes were characterized by elemental analyses, conductance, and magnetic measurements, as well as by IR and UV-Vis spectroscopy. The low values of the molar conductance indicate nonelectrolyte type of complexes. Based on spectral data and magnetic moments, an octahedral geometry may be proposed for Co(II), Ni(II), and Zn(II) complexes while a tetragonal geometry for Cu(II) complex. Molecular structure of the Schiff base ligand and its complexes were studied using programs dedicated to chemical modeling and quantomolecular calculation of chemical properties. All the synthesized complexes were tested forin vitroantibacterial activity against some pathogenic bacterial strains, namelyEscherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis,andStaphylococcus aureus. The MIC values shown by the complexes against these bacterial strains revealed that the metal complexes possess superior antibacterial activity than the Schiff base.

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