scholarly journals Synthesis, Characterization and Antimicrobial Studies of Some New Tellurium(IV) Complexes Derived from 2-[(2-Hydroxyphenyl)imino methyl]-1-naphthol Schiff Base

2021 ◽  
Vol 34 (1) ◽  
pp. 183-190
Author(s):  
Mahak Dalal ◽  
Manish Kumar ◽  
K.K. Verma ◽  
Sapana Garg

This article reports the synthesis, characterization and antimicrobial screening of a tridentate 2-[(2-hydroxyphenyl)imino methyl]-1-naphthol ligand (H2AP) and its organotellurium(IV) complexes. Structural characterization of the synthesized ligand and complexes was confirmed by using FT-IR, 1H NMR, 13C NMR, UV-vis, mass spectrometry, molar conductance and elemental analysis. Geometry of all the synthesized compounds has been optimized and their DFT based chemical reactivity descriptors were calculated. DFT and spectral data studies revealed distorted square pyramidal geometry for the tellurium(IV) complexes. In vitro antimicrobial activities of the synthesized ligand and its tellurium(IV)complexes were evaluated against two Gram-positive, two Gram-negative bacterial strains and three fungal strains. The tellurium(IV) complexes exhibited promising activity as compared to the Schiff base ligand.

2021 ◽  
Vol 37 (5) ◽  
pp. 1146-1151
Author(s):  
Suman Kumari ◽  
Shobhana Sharma ◽  
Seema Seema ◽  
Poonam Yadav ◽  
Mamta Ranka

In our present research work, we have synthesized two ternary metal complexes of Mn(II), complex-I as [Mn(L)(Gly)(Cl)(H2O)] and complex-II as [Mn(L)(Q)(Cl)(H2O)]; where L is Isatinphenylhydrazone (IPH) as primary ligand, whereas glycine (Gly) and 8-hydroxyquinoline (HQ) as secondary ligand in complex-I and II respectively, in 1:1:1 (M : L : Gly or M : L : Q) molar ratios. Above synthesized complexes are employed for characterization using various analytical techniques including elemental analysis, melting point determination, magnetic moment measurements, molar conductance measurements, and spectral techniques (FTIR, UV, 1H NMR) etc. Further, their antimicrobial activities were evaluated against selected bacterial strains i.e., B. subtilis, S. aureus (Gram positive) and P. aeruginosa, E. coli (Gram negative) and fungal strains (T. reesei, A. niger, C. albicans) and found significantly active.


2021 ◽  
Vol 9 (09) ◽  
pp. 900-909
Author(s):  
Anupama Srivastava ◽  
◽  
Shilpi Srivastava ◽  
Om. P. Pandey ◽  
Soumitra K. Sengupta ◽  
...  

Titanium(IV) complexes of type[(η5-C5H5)2TiCl(L)] have been synthesized by the reactions of bis(cyclopentadienyl)titanium(IV)dichloride with Schiff bases (LH) derived by the condensation of 5-(substituted aryl)-2-hydrazino-1,3,4-oxadiazole and indoline-2,3-dione in tetrahydrofuranin the presence oftriethylamine. All these complexes are soluble in PhNO2, DMF and DMSO.The complexes were characterized by elemental analyses, electrical conductance, magnetic susceptibility, UV-Vis, IR, 1H NMR, 13C NMR, XRD and SEM spectral techniques. Low molar conductance values indicate that they are non-electrolytes. The spectral data indicate5-coordinate geometry for the complexes.XRD pattern indicate that the complexes have monoclinic crystal system and particle sizes were found 49.36 nm (nano-size). In vitro antifungal activity of synthesized compounds was evaluated against fungi Aspergillusniger, Aspergillusflavus,ColletotrichumfalcatumandIn vitro antibacterial activity was determined by screening the compounds against gram negative (P. aeruginosa, S.typhi) and gram positive (S. aureus and B.subtilis) bacterial strains using minimum inhibition concentration method (MIC) by serial dilution technique. The titanocene(IV) complexes have higher antimicrobial effect than the parent Schiff bases.


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.


2020 ◽  
Vol 12 (8) ◽  
pp. 1137-1148 ◽  
Author(s):  
Asma S. Al-Wasidi ◽  
Nawal M. Al-Jafshar ◽  
Amal M. Al-Anazi ◽  
Moamen S. Refat ◽  
Nashwa M. El-Metwaly ◽  
...  

In this article, four new Schiff base complexes of Mn(II), Co(II), Ni(II) and Cu(II) complexes have been synthesized with two different compositions as [M(L)2Cl2] · nH2O and [M(L)2(H2O)2]Cl2 · nH2O [where L1 = benzoin-o-amino benzoic acid (aromatic β amino acid) and L2 = benzoin bromo-o-amino benzoic acid (aromatic β amino acid); M = MnII, CoII, NiII and CuII; n = 1, 2 and 4]. These Schiff base complexes were discussed by many tool of analyses like elemental analysis, magnetic susceptibility, molar conductance, mass spectra, infrared spectra "IR," proton nuclear magnetic resonance "1H-NMR," electronic spectral and thermogravimetric analysis (TG/DTG). These complexes have an electrolytic nature within range of 78–174 Ω1 cm–1 mol –1 based on conductance measurements. Magnetic moment and electronic spectral results deduced that the geometry of Mn2+, Co2+ and Ni2+ and Cu2+ complexes has an octahedral configuration. The number of coordinated and uncoordinated water molecules for the synthesized complexes were calculated based on the thermal analysis technique. The kinetic thermodynamic data were estimated by using commonly integral equations of Horowitz-Metzger (HM) and Coats-Redfern (CR). In vitro the antimicrobial activity of both free L1 and L2 ligands in comparable with their metal complexes were evaluated. This study was strengthen by molecular docking against three protein receptors, which attributing to selected organisms already used in vitro study.


2019 ◽  
Vol 84 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Chinnaraj Kanagavalli ◽  
Murugesan Sankarganesh ◽  
Raja Dhaveethu ◽  
Manivannan Kalanithi

Novel series of Co(II), Ni(II) and Cu(II) transition metal complexes were synthesized from the Schiff base ligands HL1?HL4 derived from 2-amino-6- nitrobenzothiazole with various aromatic aldehydes, i.e., 4-methylbenzaldehyde, 4- ethylbenzaldehyde, 2-hydroxybenzaldehyde and 4-hydroxybenzaldehyde, respectively. The ligands HL1?HL4 and their metal (II) complexes were characterized by atomic absorption spectroscopy (AAS), magnetic susceptibility and molar conductance measurements, and UV?Vis, FT-IR and NMR spectroscopic techniques. The spectroscopic studies revealed that the complexes of HL1?HL3 coordinated in an octahedral environment and L4 in square planar/tetrahedral geometry. The ligands HL1?HL4 and their metal(II) complexes were screened for their antimicrobial activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The results suggest that the complexes of HL4 possess greater inhibition activity towards C. albicans. The nonlinear optics (NLO) activities of ligands HL1?HL4 were determined. The obtained results showed that ligands HL1 and HL2 have greater second harmonic generation (SHG) efficiency than HL3and HL4.


2019 ◽  
Vol 9 (1) ◽  
pp. 3776-3782 ◽  

A Schiff base ligand L was prepared from the condensation of 2-amino-3-benzyloxypyridine and 5-chlorosalicylaldehyde. The ligand forms complexes with Co(III) and VO(IV) in good yield. Design, synthesized and characterization of cobalt(III) and oxidovanadium(IV) with (E)-2-((3-(benzyloxypyridinylimino) methyl)-4-chlorophenol (L) are described. The prepared complexes were characterized by different analytical techniques elemental analysis, molar conductance, infrared spectra, 1H and 13C NMR, mass, electronic absorption and TGA. The coordination geometry is octahedral in C1 and C2, while complexes C3 and C4 show a square-pyramidal geometry. Numerous biological studies have been conducted on L and Co(III) and VO(IV) complexes. The results of antimicrobial studies indicated that all compounds had antimicrobial activity against bacteria and fungi. The binding of metal complexes with BSA (bovine serum albumin) was reported. The results of these indicated that Co(III) and VO(IV) are significantly quenching fluorescence intensity of BSA, that results in changing its conformation and results in a static quenching.


2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Aurora Reiss ◽  
Mariana Carmen Chifiriuc ◽  
Emilia Amzoiu ◽  
Cezar Ionuţ Spînu

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.


2021 ◽  
Vol 35 (1) ◽  
pp. 97-106
Author(s):  
A. O. Rajee ◽  
H. F. Babamale ◽  
A. Lawal ◽  
A. A. Aliyu ◽  
W. A. Osunniran ◽  
...  

Four complexes of Mn(II), Co(II), Ni(II) and Cu(II) with Schiff base ligand (H3L) derived from 2-amino-3-methylbutanoic acid and acetylacetonate were synthesized. All complexes were characterized by elemental analysis, Fourier-transform infrared spectroscopy and electronic spectroscopy. The results confirmed the coordination of the ligand to metals in tridentate fashion via the hydroxyl oxygen, the azomethine nitrogen and the enolic acetylacetonate oxygen. Antimicrobial activities were established for all complexes, free ligand and ciprofloxacin for comparison. Both the ligand and its metal complexes were active against Gram-positive and negative bacterial strains. The Cu(II) complex, showed highest antibacterial activity among the complexes screened. Other complexes displayed considerable antibacterial activity. Octahedral geometry was proposed for the metal(II) complexes with the Schiff base.                     KEY WORDS: Schiff base, Amino acid, Metal Complexes, Antibacterial agents   Bull. Chem. Soc. Ethiop. 2021, 35(1), 97-106. DOI: https://dx.doi.org/10.4314/bcse.v35i1.8


2014 ◽  
Vol 79 (4) ◽  
pp. 435-443 ◽  
Author(s):  
Selma Spirtovic-Halilovic ◽  
Mirsada Salihovic ◽  
Hurija Dzudzevic-Cancar ◽  
Snezana Trifunovic ◽  
Suncica Roca ◽  
...  

In the present investigation, a series of coumarin-based compounds containing a chalcone moiety were studied for their in vitro and in silico properties. DFT global chemical reactivity descriptors (chemical hardness, total energy, electronic chemical potential and electrophilicity) are calculated for four synthesized compounds and used to predict their relative stability and reactivity. The antibacterial activities of all compounds have been screened against Bacillus subtilis (ATCC No. 6633) and Bacillus cereus (ATCC No. 11778). Quantum-chemical calculations indicate that antibacterial activity correlates well with chemical reactivity descriptors of molecules.


2010 ◽  
Vol 75 (2) ◽  
pp. 217-228 ◽  
Author(s):  
Dharmpal Singh ◽  
Krishan Kumar ◽  
Ramesh Kumar ◽  
Jitender Singh

A novel series of complexes of the type [M(C28H24N4)X2], where M = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), X = Cl-, NO3 -, CH3COO- and (C28H24N4) corresponds to the tetradentate macrocyclic ligand, were synthesized by template condensation of 1,8-diaminonaphthalene and diacetyl in the presence of divalent metal salts in methanolic medium. The complexes were characterized by elemental analyses, conductance and magnetic measurements, as well as by UV/Vis, NMR, IR and MS spectroscopy. The low values of the molar conductance indicate non-electrolyte type of complexes. Based on these spectral data, a distorted octahedral geometry may be proposed for all of these complexes. All the synthesized macrocyclic complexes were tested for in vitro antibacterial activity against some pathogenic bacterial strains, viz Bacillus cereus, Salmonella typhi, Escherichia coli and Staphylococcus aureus. The MIC values shown by the complexes against these bacterial strains were compared with the MIC shown by the standard antibiotics linezolid and cefaclor.


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