Bimetallic complexes of Schiff base bis-[4-hydroxycuomarin-3-yl]-1N,5N-thiocarbohydrazone as a potentially dibasic pentadentate ligand. Synthesis, spectral, and antimicrobial properties

2008 ◽  
Vol 5 (1) ◽  
pp. 122-134 ◽  
Author(s):  
K. S. Abou-Melha ◽  
H. Faruk
Keyword(s):  
Schiff Base ◽  
Antimicrobial Properties ◽  
Bimetallic Complexes ◽  
Ligand Synthesis ◽  
Pentadentate Ligand

The first pentagonal-bipyramidal vanadium(iii) complexes with a Schiff-base N3O2 pentadentate ligand: synthesis, structure and magnetic properties

2020 ◽  
Vol 49 (43) ◽  
pp. 15287-15298
Author(s):  
Tamara A. Bazhenova ◽  
Leokadiya V. Zorina ◽  
Sergey V. Simonov ◽  
Vladimir S. Mironov ◽  
Olga V. Maximova ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Schiff Base ◽  
Ligand Synthesis ◽  
Pentadentate Ligand

A series of three mononuclear pentagonal-bipyramidal V(iii) complexes with the equatorial pentadentate N3O2-ligand were synthesized and characterized structurally and magnetically.

scholarly journals Synthesis, characterization, and biological evaluation of some 4-((thiophen-2-yl-methylene)amino)benzenesulfonamide metal complexes

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
E. Vijaya Sekhar ◽  
Subhas S. Karki ◽  
Javarappa Rangaswamy ◽  
Mahesh Bhat ◽  
Sujeet Kumar
Keyword(s):  
Escherichia Coli ◽  
Schiff Base ◽  
Aspergillus Niger ◽  
Metal Complexes ◽  
Antimicrobial Properties ◽  
Azomethine Nitrogen ◽  
Diffusion Method ◽  
Sulfa Drugs ◽  
Zone Of Inhibition ◽  
Penicillium Rubrum

Abstract Background Sulfonamides (sulfa drugs) and the metals like mercury, copper, and silver bear antimicrobial properties. The discovery of broad-spectrum antibiotics such as penicillins, cephalosporins, and fluoroquinolones has reduced their use. However, in some instances these drugs are the first-line treatment. The metal-based sulfonamide (e.g., silver sulfadiazine) is considered as first choice treatment in post-burn therapy while the use of silver nanoparticle-cephalexin conjugate to cure Escherichia coli infection explains the synergistic effect of sulfa drugs and their metal conjugates. With growing interest in metal-based sulfonamides and the Schiff base chemistry, it was decided to synthesize sulfonamide Schiff base metal complexes as antioxidant and antimicrobial agent. Results The Fe (III), Ru (III), Co (II), Ni (II), Cu (II), Pd (II), Zn (II), Cd (II), and Hg (II) metal complexes of 4-((thiophen-2-ylmethylene)-amino)-benzenesulfonamide (TMABS) were prepared and studied for thermal stability, geometry, and other electronic properties. The ligand TMABS (Schiff base) and its metal complexes were screened in-vitro for 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and antimicrobial properties against Gram-positive (+ve) Bacillus subtilis (MTCC-441), Staphylococcus aureus (MTCC 7443), Gram-negative (-ve) Escherichia coli (MTCC 40), Salmonella typhi (MTCC 3231), and fungal strains Aspergillus niger (MTCC-1344) and Penicillium rubrum by agar well diffusion method. Results summarized in Tables 3, 4, and 5 represent the inhibitory concentration (IC50) in micromole (μM). The zone of inhibition (ZI) in millimeter (mm) represents antimicrobial properties of TMABS and its metal complexes. Conclusions The synthesized sulfanilamide Schiff base (TMABS) behaved as a neutral and bidentate ligand coordinating with metal ions through its azomethine nitrogen and thiophene sulfur to give complexes with coordination number of 4 and 6 (Fig. 3). The nucleophilic addition of sulfanilamide amino group (–NH2) group to carbonyl carbon (>C=O) of benzaldehyde gave sulfanilamide Schiff base (imine) (Fig. 2). All the metal complexes were colored and stable at room temperature. With IC50 of 9.5 ± 0.1 and 10.0 ± 0.7 μM, the Co, Cu, and Pd complexes appeared better antioxidant than the ligand TMABS (155.3±0.1 μM). The zone of inhibition (ZI) of Hg (28 mm) and Ru complexes (20 mm) were similar to the ligand TMABS (20 mm) against Aspergillus niger (MTCC-1344) as in Figs. 4, 5, and 6. None of the synthesized derivatives had shown better antimicrobial properties than the standard streptomycin sulfate and fluconazole.

scholarly journals Turning on ROP activity in a bimetallic Co/Zn complex supported by a [2+2] Schiff-base macrocycle

2019 ◽  
Vol 55 (75) ◽  
pp. 11279-11282 ◽  
Author(s):  
Kuiyuan Wang ◽  
Timothy J. Prior ◽  
Carl Redshaw
Keyword(s):  
Schiff Base ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Bimetallic Complexes

Homo-dinuclear Co or Zn complexes derived from a [2+2] Schiff-base macrocycle revealed near inactivity for the ring opening polymerization of δ-valerolactone and ε-caprolactone, whereas hetero-bimetallic complexes were efficient catalysts.

scholarly journals End-on cyanate or end-to-end thiocyanate bridged dinuclear copper(ii) complexes with a tridentate Schiff base blocking ligand: synthesis, structure and magnetic studies

2018 ◽  
Vol 42 (3) ◽  
pp. 1634-1641 ◽  
Author(s):  
Samim Khan ◽  
Stephen Sproules ◽  
Louise S. Natrajan ◽  
Klaus Harms ◽  
Shouvik Chattopadhyay
Keyword(s):  
Schiff Base ◽  
Magnetic Studies ◽  
Dinuclear Copper ◽  
End To End ◽  
Ligand Synthesis ◽  
Tridentate Schiff Base

Two new dinuclear Schiff base copper(ii) complexes have been synthesized and characterized. Copper(ii) centres are ferromagnetically coupled in1and antiferromagnetically coupled in2.

scholarly journals Synthesis, characterization and biological activity of a Schiff base derived from o-amino benzoic acid and its Co(II), Cd(II) and Ni(II) complexes

2020 ◽  
Vol 11 (1) ◽  
pp. 15-20
Author(s):  
Tasneem Ibrahim Hussein ◽  
Musa Abduelrahman Ahmed ◽  
Ismail Adam Arbab ◽  
Awad Salim Ibrahim ◽  
Mohamed Al-Bratty ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Schiff Base ◽  
Mass Spectra ◽  
Free Ligand ◽  
Antimicrobial Properties ◽  
Proton Nuclear Magnetic Resonance ◽  
Complexing Agent ◽  
Diffusion Technique ◽  
Nuclear Magnetic Resonance Spectra

Equimolar amounts of imidazoleacetophenone and 2-aminobenzoic acid were combined together and the Schiff base 4(1H-imidazole-yl)acetophenoneanthranilic acid was prepared as a new bidentate complexing agent. The synthesized ligand was reacted with cobalt(II), cadmium(II), and nickel(II) ions yielding air stable complexes. For quantification and characterization purposes, elemental analysis, infrared spectra, electronic spectra, proton nuclear magnetic resonance spectra and mass spectra studies were carried out on the obtained complexes and ligand. Thermogravimetric analysis and magnetic susceptibility measurements were also used for characterization. The ligand IR spectrum showed that the ligand acts as a bidentate coordinates to the metal ions through the nitrogen and oxygen atoms.Measurements of magnetic susceptibility for Ni(II) and Co(II) complexes were found to be 3.4 and 3.8 B.M., respectively, in the range normal for the octahedral geometry. The conductivity measurements revealed that the chelates are non-electrolytes. An in vitro antimicrobial investigation was also carried out for the free ligand and its metal complexes against a number of bacterial and fungal strains, to assess their antimicrobial properties by diffusion technique. Antimicrobial activity of the prepared complexes showed higher activity than the free ligand.

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