scholarly journals Bioactive Metal Complexes of Schiff Base Derived from 2,3-Dioxobutane, Ethane-1,2-diamine and 4-Chloro-2-formylphenol: Spectral Studies and in vitro Antimicrobial Activity

2021 ◽  
Vol 33 (12) ◽  
pp. 3063-3069
Author(s):  
Abhay Nanda Srivastva ◽  
Sayanwita Panja ◽  
Netra Pal Singh ◽  
Chandra Kiran Shriwastaw

A novel series of trivalent coordination complexes was synthesized by the reaction between a chloride/ acetate salt of iron, chromium, cobalt or manganese ions and NNNNOO type persuasive Schiff base ligand synthesized from 2,3-dioxobutane, ethane-1,2-diamine and 4-chloro-2-formylphenol. Synthesized compounds were characterized by using elemental analysis, molar conductance, magnetic moment, IR, UV-visible, 1H NMR, 13C NMR and ESI-MS spectral analyses. IR and NMR spectra favoured hexadentate coordination behaviour of ligand. Electronic spectra and magnetic moment data reveal Oh geometry with distortion around the metal ion in complexes. The molar conductance values show 1:1 electrolytic nature of complexes. Biological potentiality of the ligand and its metal complexes were tested in vitro against two bacterial and two fungal strains; Bacillus subtilis, Escherichia coli and Aspirgillus niger, Aspirgillus flavus, respectively.

2007 ◽  
Vol 2007 ◽  
pp. 1-7 ◽  
Author(s):  
Sulekh Chandra ◽  
Smriti Raizada ◽  
Monika Tyagi ◽  
Archana Gautam

A series of metal complexes of Cu(II) and Ni(II) having the general composition[M(L)X2]with benzil bis(thiosemicarbazone) has been prepared and characterized by element chemical analysis, molar conductance, magnetic susceptibility measurements, and spectral (electronic, IR, EPR, mass) studies. The IR spectral data suggest the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, an octahedral geometry has been assigned for Ni(II) complexes but a tetragonal geometry for Cu(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties.


2014 ◽  
Vol 79 (4) ◽  
pp. 421-433 ◽  
Author(s):  
Abhay Srivastava ◽  
Netra Singh ◽  
Chandra Shriwastaw

A series of novel binuclear transition metal complexes was synthesized by reaction of a Schiff base ligand (1-Methyl-2-(2-oxo-1,2-dihydro-pyrimidin-4-ylimino)-propylideneamino-acetic acid) (LaH) derived from 4-amino-pyrimidine-2-one, diacetyl, glycine and corresponding chloride salt of Cu(II), Ni(II), Co(II) and Zn(II) metals in 1:1 (metal : ligand) molar ratio. The compounds were characterized by elemental analyses, molar conductance measurement, magnetic moment measurement and various spectral studies viz. IR, UV-visible, 1H-NMR, 13C-NMR, EPR and ESI-MS. Molar conductance measurement data revealed non-electrolytic nature of metal complexes. Electronic absorption spectral data, electronic paramagnetic resonance parameters and magnetic moment values revealed an octahedral geometry for binuclear metal complexes. Cyclic voltammetric study of Ni(II) complex shows a couple of one electron anodic responses near 0.70 V and 1.10 V. In vitro biological activity of Schiff base ligand and binuclear complexes has been checked against bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Salmonella typhi) and fungi (Candida albicans and Candida parapsilosis) to assess their antibacterial and antifungal properties.


2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
Sulekh Chandra ◽  
Shikha Parmar ◽  
Yatendra Kumar

A series of metal complexes of Zn(II) and Hg(II) having the general composition [where L = 2-formylpyridine thiosemicarbazone; M = Zn(II) and Hg(II); X = , and ] have been prepared and characterized by elemental chemical analysis, molar conductance, and spectral (IR and mass) studies. The IR spectral data suggests the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, a tetrahedral geometry has been assigned for Zn(II) and Hg(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties.


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.


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):  
AMAL M ALOSAIMI ◽  
INES EL MANNOUBI ◽  
SAMI A ZABIN

Objective: This work aimed at synthesizing tridentates asymmetrical Schiff base ligands containing sulfur atom and using them for preparing metal complexes with the iron triad metals. The prepared compounds were assayed in vitro for antimicrobial potential and in vivo molluscicidal activity. Methods: The unsymmetrical tridentate Schiff bases (SL1, SL2, and SL3) were prepared using 2-aminothiophenol as primary amine and condensed with 2-carboxybenzaldehyde, 2-hydroxy-1-naphthaldehyde, and 7-formyl-8-hydroxyquinoline. These ligands were used in preparing metal complexes with iron triad metals. The synthesized Schiff base ligands and their corresponding metal complexes were characterized and their proposed structures were confirmed using different physical and spectroscopic analytical techniques. All ligands and their corresponding metal complexes were assayed against different bacterial and fungal strains using the agar disk-diffusion technique. The molluscicidal activity was performed according to the standard reported methods as cited in the literature and by observing the toxicity and lethal dose according to the WHO guidelines. Results: The synthesized ligands behave as tridentate (NOS) ligands and form mononuclear complexes with the general formula [M(SL)2] with an octahedral geometry around the central metal ion. Metal complexes were non-electrolytic in nature. The in vitro antibacterial and antifungal examination results showed weak activity of the ligands, and there was enhanced activity with the complexes. The in vivo molluscicidal activity of the tested compounds showed good activity. Conclusion: The targeted compounds were prepared successfully, characterized, and showed some biological activity but lower than the standard reference drugs.


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.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Har Lal Singh ◽  
Jangbhadur Singh

New series of organotin(IV) complexes and Schiff bases derived from amino acids have been designed and synthesized from condensation of1H-indole-2,3-dione, 5-chloro-1H-indole-2,3-dione, andα-amino acids (phenylalanine, isoleucine, and glycine). All compounds are characterized by elemental analyses, molar conductance measurements, and molecular weight determinations. Bonding of these complexes is discussed in terms of their UV-visible, infrared, and nuclear magnetic resonance (1H,13C, and119Sn NMR) spectral studies. The results suggest that Schiff bases behave as monobasic bidentate ligands and coordinate with dibutyltin(IV) in octahedral geometry according to the general formula [Bu2Sn(L)2]. Elemental analyses and NMR spectral data of the ligands with their dibutyltin(IV) complexes agree with their proposed distorted octahedral structures. Few representative compounds are tested for their in vitro antibacterial activity against Gram-positive (B. cereus,Staphylococcusspp.) and Gram-negative (E. coli,Klebsiellaspp.) bacteria. The results show that the dibutyltin complexes are more reactive with respect to their corresponding Schiff base ligands.


2012 ◽  
Vol 77 (5) ◽  
pp. 627-637 ◽  
Author(s):  
Pal Singh ◽  
Nanda Srivastava

Mononuclear metal complexes of the type [ML1]Cl2 (where, M = = Cu(II), Co(II) or Ni(II) and L1 = ligand) were synthesized by the reaction of a new N4 coordinating ligand, derived from diacetylbisethylenediamine with benzoic acid, and the corresponding hydrated metal chloride salts. The metal complexes were characterized by elemental analysis, melting point determination, molar conductance and magnetic moment measurements, IR, UV-Vis, 1H- and 13C-NMR, and ESR spectroscopy. The ligand and all the metal complexes were stable in the solid state at room temperature. From the analytical and spectroscopic investigations, the stoichiometry of the complexes was found to be 1:1 (metal:ligand). Based on the electronic spectra and magnetic moment data, the metal complexes had a square planar geometry. The molar conductance values show the 1:2 electrolytic nature of the metal complexes. A cyclic voltammetric study of the Cu(II) metal complex has also performed, which showed one electron quasi-reversible reduction around -0.92 to -1.10 V. In vitro biological activities of the ligand and metal complexes was checked against two bacteria Bacillus subtilis and Escherichia coli and two fungi Aspirgillus niger and A. flavus which showed the antibacterial and antifungal properties of the ligand and its metal complexes.


2020 ◽  
Vol 32 (7) ◽  
pp. 1768-1772
Author(s):  
Anita Rani ◽  
Manoj Kumar ◽  
Hardeep Singh Tuli ◽  
Zahoor Abbas ◽  
Vinit Prakash

The study describes the synthesis, characterization and biological activity of a novel Schiff base ligand and its transition metal complexes. The Schiff base ligand was obtained by a condensation reaction between 4-hydroxy-3-methoxybenzaldehyde (p-vanillin) and hydrazine hydrate using ethanol as solvent. A new series of Ni(II) and Fe(III) complexes were also derived by reaction of prepared Schiff base ligand with NiCl2 and FeCl3. Both the ligand and its metal complexes were characterized by solubility, melting point and elemental analysis. These compounds were further identified by analytical techniques, FTIR, NMR and mass spectrometry. The ligand and its transition metal complexes were also subjected to in vitro biological activities i.e. antimicrobial, antiangiogenic and DNA photo cleavage. For antimicrobial activity compounds were tested against two strains of bacteria and two strains of fungi. Different concentrations of prepared compounds were treated with fertilized chicken eggs and plasmid DNA to find out antiangiogenic and DNA photocleavage activity, respectively.


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