Metal Complexes of Schiff Bases Derived from 2-Thiophenecarboxaldehyde and Mono/Diamine as the Antibacterial Agents (original) (raw)
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Earthline Journal of Chemical Sciences
Schiff base ligand derived from condensation of 2-aminothiophenol and 2-thiophene carboxyldehy was synthesized and used for the preparation of Cr(II), Mn(II) and Co(II), complexes. The synthesized ligand and complexes were analyzed by decomposition temperature, solubility, magnetic susceptibility, molar conductance and infrared spectra. The decomposition temperatures of the complexes are in the range of 128-221ºC. Molar conductance values are in the range of 6.07-9.10 ohm-1cm2mol-1. New bands appeared in the IR spectra of the complexes in the range of 511-552 cm-1 and 438-473 cm-1 which indicate υ(M - N) and υ(M - S) vibrations respectively. Magnetic susceptibility measurement indicated that all complexes are paramagnetic while solubility test revealed that all complexes and ligand are soluble in DMSO. The analytical data show the formation of 2:1 metal to ligand ratio for all complexes and suggested the formula [ML2].nH2O.The ligand and metal chelates have been studied for microbia...
Schiff base namely 4-((thiophene-2-yl) methyleneamino) phenyl sulfonamide (L) and its Co (II), Ni (II), Cu (II) and Zn (II) complexes were synthesized and characterized by UV-Vis, IR, 1H-NMR, MS-EI, elemental analysis and TGA. Molar conductance and Magnetic susceptibility of the complexes were also analyzed. Elemental analyses confirmed a 2:1 molar ratio of ligand to metal ion of the complexes. IR spectra revealed that L is coordinated to the metal ions through azomethine-N and Thiophene-S. On the basis of experimental data octahedral geometry was proposed for all complexes. Thermal studies together with IR showed the presence of lattice and coordinated water molecules in all complexes. The in vitro antimicrobial activities of the compounds were tested against S.aureus, K.pneumoniae , C. albicans and C.krusei by the agar well diffusion assay. The result indicated that the ligand become antimicrobially active on chelation with metal ions. It was found that Cu(II) complex showed the highest antibacterial activity among all complexes.
International Journal of Pharma Research and Health Sciences, 2014
The Metal complexes of Co (II), Ni (II), Cu (II) and Hg (II) with a new Schiffbase derived from 2-Acetyl 5-chloro thiophene and o-Phenylenediamine in methanol are reported. The complexes have been characterized using chemical analysis, (IR, UV-VIS, H1-NMR), conductometric and magnetic data. According to these data, we propose an octahedral geometry for metal (II) complexes. The invitro antibacterial activities of the investigated complexes were evaluated against few microorganisms by well diffusion technique. It was found that the metal complexes have higher activity that the standard drugs. Antibacterial activity of the ligand and its complexes were studied against to gram positive acteria; Staphylococcus aureus and Bacillus subtilis and gram negative bacteria Salmonellatyphi and E. coli.
Oriental Journal of Chemistry
A series of di-and triorganotin 3,6-dioxaheptanoates and 3,6,9-trioxadecanoates were synthesized and characterized by IH, 13C and l7Sn NMR, electrospray mass and l9mSn M6ssbauer spectroscopy, as well as elemental analysis. Their in vitro antitumour activity against seven tumoural cell lines of human origin, two breast cancers (MCF-7, EVSA-T), a colon carcinoma (WiDr), an ovarian cancer (IGROV), a melanoma (M19 MEL), a renal cancer (A 498) and a non small cell lung cancer (H 226), is reported. They are characterized by similar inhibition doses IDs0 as the analogous di-and triorganotin derivatives of 4-carboxybenzo-15-crown-5 and-18-crown-6 and in some cases by much lower IDs0 values than clinically used reference compounds such as doxorubicine and methotrexate.
Transition metal complexes with a 2-thiophenecarboxaldehyde-derived Schiff base
Transition metal complexes of Schiff base derived from the condensation of 3-aminodibenzofuran with 2-thiophencarboxaldehyde, are reported and characterized. An octahedral geometry for Co(II), Ni(II) and Cu(II) complexes and a tetrahedral geometry for Zn(II), Cd(II) and Hg(II) complexes are proposed. Antibacterial activity of the ligand and its complexes were studied against selected bacteria.
2020
New Schiff base ligand was synthesis via a condensation of the ligands in methanol. The Schiff base were synthesize in 1:2 molar ratio reactions. The complexes have been characterized on the basis of FTIR, electronic spectra, melting points, solubility and molar conductance. The invitro antibacterial activity of the complexes were tested using four bacteria strain; gram negative (Escherichia coli, salmonella typhi) and gram positive (staphylococcus pyogenes and staphylococcus aureus). The complexes were formed in good yield and they have various shades of colors and sharp melting points. The IR results for the HL synthesized schiff base revealed bands at 1621cm which shifted to higher frequencies in the metal complexes 1622, 1626 and 1621 cm,. The band at 690, 666, 696 cmand 593, 549,579 cm(HL), were assigned to (M-N) and (M-O) bands in the spectra of the complexes supporting coordination of Schiff base/ligands to respective metals.The electronic spectral data of the complexes sugge...
Metal Complexes of Schiff Bases: Preparation, Characterization, and Biological Activity
Metal complexes of Schiff bases derived from 2-furancarboxaldehyde and o-phenylenediamine (L 1 ), and 2-thiophenecarboxaldehyde and 2-aminothiophenol (HL 2 ) are reported and characterized based on elemental analyses, IR 1 H NMR, solid reflectance, magnetic moment, molar conductance, and thermal analysis (TGA). The ligand dissociation, as well as the metal-ligand stability constants were calculated, pH-metrically, at 25 • C and ionic strength μ = 0.1 (1 M NaCl). The complexes are found to have the formulae [M(L 1 )(H2O)2](Cl)n·yH2O (where M = Fe(III), Ni(II), Cu(II); n = 2-3, y = 2-4); [M(L 1 )](X)2·yH2O (where M = Co(II), Zn(II), UO2(II), X = Cl, AcO or NO3, y = 1-3); [M(L 2 )2]·yH2O
Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2011
Schiff base namely 2-aminomethylthiophenyl-4-bromosalicylaldehyde (ATS)(4-bromo-2-(thiophen-2yl-imino)methylphenol) and its metal complexes have been synthesized and characterized by elemental analyses, IR, 1 H NMR, solid reflectance, magnetic moment, molar conductance, mass spectra, ESR and thermal analysis (TGA). The analytical data of the complexes show the formation of 1:2 [M:L] ratio of the formula [ML 2 ], where M represents Ni(II), Zn(II) and Cu(II) ions, while L represents the deprotonated Schiff base. IR spectra show that ATS is coordinated to the metal ions in a bidentate manner through azomethine-N and phenolic-oxygen groups. The ligand and their metal chelates have been screened for their antimicrobial activities using the disc diffusion method against the selected bacteria. A cytotoxicity of the compounds against colon (HCT116) and larynx (HEP2) cancer cells have been studied. Protonation constants of (ATS) ligand and stability constants of its Cu 2+ , Co 2+ , Mn 2+ , Zn 2+ and Ni 2+ complexes were determined by potentiometric titration method in 50% (v/v) DMSO-water solution at ionic strength of 0.1 M NaNO 3 . (A.A. El-Sherif). ing the pH range where the compounds show minimum ionization. Additionally, protonation of a newly synthesized compound can also give supportive information about its structure. If theoretically calculated protonation constants are in good accordance with the experimental values, it is possible that the proposed structure could be correct. In continuation of our earlier work and to widen the scope of investigation on the coordination behavior of Schiff base ligand (ATS) derived from 5-bromosalicylaldehyde and 2-aminomethylthiophene, the researchers here the synthesis, characterization, equilibrium study and biological activity of (ATS) and its complexes with a number of 3d divalent metal ions. The researchers also show the protonation of the free ATS ligand and its stepwise stability constants with Cu 2+ , Co 2+ , Mn 2+ , Zn 2+ and Ni 2+ . This was done through calculation of stability constants for their complexes at different temperatures. This work is also extended to present some correlations between the thermodynamic functions and some of well-known properties of the metal ions. Such work may help to explain the nature and driving forces for the interactions occurring in biological systems, such as metal-protein and metal-nucleic acid interactions.
Asian Journal of Applied Chemistry Research
The metal (II) complexes, Na2[ML2] [M = Cu, Co, Ni, and Zn], of salicylaldehyde thiosemicarbazone (L) containing a trifunctional ONS-donor system have been synthesized and characterized on the basis of physicochemical data by elemental analysis, magnetic moment, molar conductance, and spectroscopic (electronic, IR and ESI-MS). The ligand functions as ONS tridentates producing octahedral complexes. All compounds showed significant antibacterial activity in different ranges against gram positive (Bacillus subtillus) and gram negative (Escherichia coli) bacteria.