scholarly journals Synthesis and DFT Study of the Complexation of Schiff Base Derived Curcumin and L-Tyrosine with Al(III), Ag(I), and Pb(II) Metal Ions

2021 ◽  
Vol 21 (3) ◽  
pp. 708
Author(s):  
Ali Mahmood Ali ◽  
Tagreed Hashim Al-Noor ◽  
Eid Abdalrazaq ◽  
Abdel Aziz Qasem Jbarah

The multi-dentate Schiff base ligand (H2L), where H2L=2,2'-(((1,3,5,6)-1-(3-((l1-oxidaneyl)-l5-methyl)-4-hydroxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-diylidene)bis(azaneylylidene))bis(3-(4-hydroxyphenyl)propanoic acid), has been prepared from curcumin and L- Tyrosine amino acid. The synthesized Schiff base ligand (H2L) and the second ligand 1,10-phenanthroline (phen) are used to prepare the new complexes [Al(L)(phen)]Cl, K[Ag(L)(phen)] and [Pb(L)(phen)]. The synthesized compounds are characterized by magnetic susceptibility measurements, micro elemental analysis (C.H.N), mass spectrometry, molar conductance, FT-infrared, UV-visible, atomic absorption (AA), 13C-NMR, and 1H-NMR spectral studies. The characterization of the synthesized complexes shows that the environment surrounding the central metal ion in the complexes adopted a distorted octahedral configuration. Moreover, the conductivity measurements show a non-electrolytic character for the [Pb(L)(phen)] complex and an electrolytic character for the [Al(L)(phen)]Cl and K[Ag(L)(phen)] complexes. The experimental infrared data are supported by density functional theory (DFT) calculations using the B3LYP level of theory and LANL2DZ basis set. The vibrational frequencies of the molecules are computed using the optimized geometry obtained from the DFT calculations. The calculated vibrational frequencies have been compared with obtained experimental values. 1H and 13C-NMR chemical shifts were computed for the H2L ligand using the DFT/GIAO method. Additionally, the molecular electronic structures of the complexes have been investigated by DFT calculations.

2012 ◽  
Vol 9 (1) ◽  
pp. 389-400 ◽  
Author(s):  
B. Anupama ◽  
M. Padmaja ◽  
C. Gyana Kumari

A new series of transition metal complexes of Cu(II),Ni(II),Co(II), Zn(II) and VO(IV) have been synthesized from the Schiff base ligand (L) derived from 4-amino antipyrine and 5- bromo salicylaldehyde. The structural features of Schiff base and metal complexes were determined from their elemental analyses, thermogravimetric studies, magneticsusceptibility, molar conductivity, ESI-Mass, IR, UV-VIS,1H NMR and ESR spectral studies. The data show that the complexes have composition of ML2type. The UV-VIS, magnetic susceptibility and ESR spectral data suggest an octahedral geometry around the central metal ion. Biological screening of the complexes reveals that the Schiff base transition metal complexes show significant activity against microorganisms. Binding of Co(II) complex with calf thymus DNA (CT DNA) was studied by spectral methods.


2010 ◽  
Vol 7 (s1) ◽  
pp. S566-S572 ◽  
Author(s):  
Kavita Rathore ◽  
Rajiv K. R. Singh ◽  
H. B. Singh

The monofunctional bidentate Schiff base ligand (o-vanillin)p-chloroaniline and its four new complexes of chromium(III), cobalt(II), nickel(II) and copper(II) have been synthesized by classical thermal and microwave-irradiated techniques. All the new derivatives have been characterized by elemental analysis, molecular weight determinations, molar conductance measurements, UV-Vis, IR and NMR spectral studies. The IR spectral data suggest the involvement of phenolic oxygen after deprotonation and azomethine nitrogen in coordination to the central metal ion. The growth inhibiting potential of the ligands and complexes has been assessed against a variety of fungal and bacterial strains.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
J. Senthil Kumaran ◽  
S. Priya ◽  
N. Jayachandramani ◽  
S. Mahalakshmi

A new series of Cu (II), Ni (II), Co (II) and Zn (II) complexes have been synthesized from the Schiff base derived from 4-hydroxy-3-methoxybenzylidine-4-aminoantipyrine and 2-aminophenol. The structural features have been determined from their elemental analysis, magnetic susceptibility, molar conductance, Mass, IR, UV-Vis,1H-NMR,13C-NMR and ESR spectral studies. The redox behavior of the copper complex has been studied by cyclic voltammetry. The data confirm that the complexes have composition of ML2type. The electronic absorption spectral data of the complexes propose an octahedral geometry around the central metal ion. All the metal complexes with DNA structure were guided by the presence of inter-molecular C–HO and C–HN hydrogen bonds. The biological activity of the synthesized compounds were tested against the bacterial species such asBacillus subtilis, Staphylococcus aureus, Proteus vulgarisand fungal species such asCandida albicansby thewell-diffusionmethod.


2016 ◽  
Vol 69 (6) ◽  
pp. 672 ◽  
Author(s):  
R. N. Singh ◽  
Poonam Rawat ◽  
Vikas Baboo

As part of a study on pyrrole derivatives we report here a combined experimental and quantum chemical study of pyrrole 4-pyrazoline biheterocyclic derivatives. The structure of the synthesised compounds have been studied using experimental IR, UV, 1H and 13C NMR spectroscopic analyses along with density functional theory (DFT) calculations using the B3LYP functional with 6–311+G (d,p) basis set. The global, local reactivity, and thermodynamic parameters support the analysis. All the experimental vibrational bands have been discussed and assigned to normal modes on the basis of our calculations. In addition, the computed 1H and 13C NMR data, obtained by DFT calculations, are found to be in good agreement with the experimental data and serve as valuable tools in identifying the products. The vibrational analysis shows red shifts in vN–H and vC=O stretching vibrations as a result of dimer formation. The theoretical electronic absorption spectra have been calculated by using time dependent-DFT methods. The static first hyperpolarizability (β0) values for the synthesized pyrrole–pyrazoline derivatives 4A–D are calculated as 16.97 × 10–30, 47.64 × 10–30, 65.40 × 10–30, 65.39 × 10–30 esu, respectively, and increase from 4A to 4C as a result of the addition of an –NO2 acceptor in 4B and two –NO2 group acceptors in 4C. However, an additional –Cl group in 4D on the phenyl ring attached to the pyrazoline moiety does not result in a clear change from 4C. The calculated static and dynamic hyperpolarizability results show that the investigated molecules might be used as non-linear optical materials.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Nayaz Ahmed ◽  
Mohd Riaz ◽  
Altaf Ahmed ◽  
Madhulika Bhagat

The present paper deals with the synthesis and characterization of metal complex of tridentate Schiff base ligand derived from the inserted condensation of 2-aminobenzimidazole (1H-benzimidazol-2-amine) with salicylaldehyde (2-hydroxybenzaldehyde) in a 1 : 1 molar ratio. Using this tridentate ligand, complex of Zn(II) with general formula ML has been synthesized. The synthesized complex was characterized by several techniques using molar conductance, elemental analysis, FT-IR, and mass and 1HNMR spectroscopy. The elemental analysis data suggest the stoichiometry to be 1 : 1 [M : L]. The complex is nonelectrolytic in nature as suggested by molar conductance measurements. Infrared spectral data indicate the coordination between the ligand and the central metal ion through deprotonated phenolic oxygen, imidazole nitrogen of benzimidazole ring, and azomethine nitrogen atom. Spectral studies suggest tetrahedral geometry for the complex. The pure compound, synthesized ligand, and metal complex were screened for their antimicrobial activity.


2019 ◽  
Vol 31 (9) ◽  
pp. 1979-1984
Author(s):  
B. Roopashree ◽  
V. Gayathri

CuX2·6H2O (X = Cl–, Br– or ClO4–) reacted with a Schiff base ligand 2-[(3′-N-salicylidinephenyl)benzimidazole] in 1:2 mole ratio in methanol to yield brown colored complexes of types [CuCl2L]2, [CuBr1.5L1.5]2Br and [Cu(OClO3)L2]2(ClO4)2·4H2O. The complexes were characterized by analytical and spectroscopic studies such as elemental analysis, conductivity and magnetic moment measurements, thermogravimetric analysis, IR, far-IR, electronic, ESR and mass spectral studies. IR spectral studies suggested the coordination of ligand to the central metal atom via tertiary nitrogen of benzimidazole and nitrogen of azomethine group. Based on these studies, binuclear structure was proposed for all the copper complexes. The ligand and its copper(II) complexes were screened for antibacterial and antifungal activities.


2008 ◽  
Vol 73 (11) ◽  
pp. 1063-1071 ◽  
Author(s):  
N. Raman ◽  
Syed Ali ◽  
Dhaveethu Raja

A new series of transition metal complexes of Cu(II), Ni(II), Co(II) and Zn(II) have been designed and synthesized using a Schiff base (L) derived from 4-aminoantipyrine, benzaldehyde and o-phenylenediamine. The structural features were derived from their elemental analyses, magnetic susceptibility and molar conductivity, as well as from mass, IR, UV-Vis, 1H-NMR and ESR spectral studies. The FAB mass spectral data and elemental analyses showed that the complexes had a composition of the ML type. The UV-Vis and ESR spectral data of the complexes suggested a square-planar geometry around the central metal ion. The magnetic susceptibility values of the complexes indicated that they were monomeric in nature. Antimicrobial screening tests were also performed against four bacteria, viz. Salmonella typhi, Staphylococcus aureus, Escherichia coli, and Bacillus subtilis and three fungi, viz. Aspergillus niger, Aspergillus flavus and Rhizoctonia bataicola. These data gave good results in the presence of metal ion in the ligand system. The nuclease activity of the above metal complexes shows that only the copper complex cleaves CT DNA in the presence of an oxidant.


Author(s):  
Md. Mahasin Ali ◽  
Md. Nur Amin Bitu ◽  
Md. Saddam Hossain ◽  
Md. Faruk Hossen ◽  
Md. Ali Asraf ◽  
...  

Two new peroxo-complexes of Cd(II) and Zr(IV) ion containing Schiff base (SB) were synthesized and characterized by Thin Layer Chromatography (TLC), Elemental analyses, conductivity, magnetic moment measurements, UV-Vis. and FT-IR spectral studies. The Schiff base ligand derived from cinnamaldehyde and o-aminophenol participated in complexation through a single pot reaction. FT-IR spectra showed that the Schiff base ligand coordinated to the metal ion through nitrogen of azomethine group and oxygen of hydroxyl group & peroxo group (O-O). The molar conductance values indicated the non-electrolytic nature of both the complexes. Antibacterial activity of the complexes was tested against four pathogenic bacteria, two Gram-positive Staphylococcus aureus & Bacillus cereus and two Gram-negative Escherichia coli & Shigella dysenteriae with standard Kanamycin-30. The result showed that Cd(II) complex exhibited more potential antibacterial activity than the Zr(IV) complex against all the tested pathogens.


2010 ◽  
Vol 75 (3) ◽  
pp. 349-359 ◽  
Author(s):  
Achut Munde ◽  
Amarnath Jagdale ◽  
Sarika Jadhav ◽  
Trimbak Chondhekar

Complexes of Cu(II), Ni(II), Co(II), Mn(II) and Fe(II) with an asymmetric tetradentate Schiff base ligand derived from dehydroacetic acid, 4-methyl- o-phenylenediamine and salicylic aldehyde were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV-Vis, IR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a dibasic tetadentate ligand towards the central metal ion with an ONNO donor atoms sequence. From the microanalytical data, the stoichiometry of the complexes 1:1 (metal:ligand) was found. The physico-chemical data suggested square planar geometry for the Cu(II) and Ni(II) complexes and octahedral geometry for the Co(II), Mn(II) and Fe(II) complexes. The thermal behaviour (TGA/DTA) of the complexes was studied and kinetic parameters were determined by Horowitz-Metzger and Coats-Redfern methods. The powder X-ray diffraction data suggested a monoclinic crystal system for the Co(II), Mn(II) and Fe(II) complexes. The ligand and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli and fungicidal activity against Aspergillus niger and Trichoderma viride.


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