Spectral Characterization and 3D Molecular Modeling Studies of Metal Complexes Involving the O, N-Donor Environment of Quinazoline-4(3H)-one Schiff Base and Their Biological Studies

Siddappa, K.; Mane, Sunilkumar B.; Manikprabhu, Deene

doi:10.1155/2014/817365

Cited by 21 publications

(11 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The electron density on the coordinating atoms of the free ligand decreases after electron pair donation to metal ions, resulting in a relative increase in the bond length. So, it is noteworthy to mention that the active coordinating groups in complexes are more lengthen than those of the free ligand . This is exactly the case in Co(II) and Cu(II) complexes (1, 3) in which the (C–O), (CH═N), (C═N) and (C═S) bonds are longer than those of the free ligand (Table ), confirming the coordination behavior of the ligand (ONNS chromophore) and convenient with the IR and 1 H NMR spectral studies.…”

Section: Resultssupporting

confidence: 72%

Molecular modeling, spectral investigation and thermal studies of the new asymmetric Schiff base ligand; (E)‐N'‐(1‐(4‐((E)‐2‐hydroxybenzylideneamino)phenyl)ethylidene)morpholine‐4‐carbothiohydrazide and its metal complexes: Evaluation of their antibacterial and anti‐molluscicidal activity

El-Samanody

Abouel‐Enein

Emara

2018

Applied Organom Chemis

View full text Add to dashboard Cite

A new tetradentate asymmetric Schiff base ligand; (E)-N'-(1-(4-((E)-2hydroxybenzylideneamino)phenyl)ethylidene)morpholine-4-carbothiohydrazide (H 2 L) was prepared by consecutive condensation reactions between p-aminoacetophenone, salicylaldehyde and 4-morpholinethiosemicarbazide. The structures of the obtained ligand along with its Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Cr(III), Fe(III) and Ru(III) complexes were authenticated by different analytical and spectral techniques. The ligand behaves as a monobasic tetradentate one and chelates with metal ions through the deprotonated phenolic oxygen, imine nitrogen, thione sulfur and azomethine nitrogen atoms (ONNS chromophore). All nonelectrolyte metal complexes possess octahedral geometry, except Ni(II) and Cu(II) complexes (2, 3) which have tetra-coordinate structures. The thermal stability of metal complexes is higher than that of the free ligand and the general thermal degradation pathways were discussed based on thermogravimetric technique. The activation thermodynamic parameters as well as the order of reaction (n) were estimated from DTG curves by using Piloyan method. Thermogravimetric analyses and mass spectra of metal complexes confirm the number of solvents in their inner and outer spheres.Molecular modeling data were used to demonstrate the thermal decomposition pathways of the ligand and its metal complexes, confirming their chemical structures. The ESR spectra of Cu(II) complexes indicate that the unpaired electron is localized mainly in the d (x 2 -y 2 ) orbital with axial symmetry. Powder X-ray diffraction analyses for Co(II), Cu(II) and Ru(III) complexes (1,3,7) show that copper complex has a crystalline nature, whereas, cobalt and ruthenium complexes are amorphous. The ligand and its metal complexes were tested in vitro for their anti-molluscicidal activity against Eobania vermiculata. The results reveal that the investigated compounds have remarkable antimolluscicidal activities against the tested land snail with various sensitivity levels. The synthesized compounds were also screened in vitro for their

show abstract

Section: Resultssupporting

confidence: 72%

Molecular modeling, spectral investigation and thermal studies of the new asymmetric Schiff base ligand; (E)‐N'‐(1‐(4‐((E)‐2‐hydroxybenzylideneamino)phenyl)ethylidene)morpholine‐4‐carbothiohydrazide and its metal complexes: Evaluation of their antibacterial and anti‐molluscicidal activity

El-Samanody

Abouel‐Enein

Emara

2018

Applied Organom Chemis

View full text Add to dashboard Cite

show abstract

“…This is further supported by the shifting of phenolic ν (C–O) towards higher frequency, indicating the coordination of the phenolate oxygen to metal ion. The ν (HC=N) vibration of the ligand occurs at 1583 cm −1 , which is shifted to a lower frequency in the complexes, indicating the involvement of the azomethine nitrogen in chelation with the metal ion [ 14 ]. The band corresponding to ν (C=O) at 1696 cm −1 is shifted to a lower frequency, supporting the coordination of the carbonyl oxygen [ 15 ].…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Spectroscopic Characterization, and Biological Evaluation Studies of 5-Bromo-3-(((hydroxy-2-methylquinolin-7-yl)methylene)hydrazono)indolin-2-one and Its Metal (II) Complexes

Siddappa

Mayana

2014

Bioinorganic Chemistry and Applications

Self Cite

View full text Add to dashboard Cite

The Schiff base ligand 5-bromo-3-(((8-hydroxy-2-methylquinolin-7-yl)methylene)hydrazono)indolin-2-one (BHMQMHI) was prepared via condensation of 5-bromo-3-hydrazonoindolin-2-one and 7-formyl-8-hydroxy-2-methylquinoline and its Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II) complexes have been synthesized and characterized by elemental analysis, conductance data, magnetic susceptibility measurements, IR, UV-Vis, mass spectrometry, 1H NMR, ESR, XRD, and thermal studies. By these spectral studies it is found that Co(II), Ni(II), and Cu(II) complexes have exhibited octahedral geometry whereas the Zn(II), Cd(II), and Hg(II) complexes have exhibited tetrahedral geometry. Potentiometric studies have been carried out on complexes of Schiff base (BHMQMHI) with Cu(II), Co(II), and Ni(II). Calvin-Bjerrum pH-titration technique as used by Irving and Rossotti has been applied to determine stability constants in mixed solvents at 25 ± 1°C. The present study reports the protonation constants of this ligand and stability constants of its metal complexes in dioxane-water (50%, v/v) mixtures. Metal-ligand stability constants fall in the order of Cu(II) > Co(II) > Ni(II) which is in agreement with those reported by Irving stability order. The Schiff base (BHMQMHI) and its metal complexes have been screened for their in vitro antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage activities of all the complexes were studied by agarose gel electrophoresis method. In addition, the free ligand along with its complexes has been studied for their antioxidant activity.

show abstract

“…Cu(II) complex showed higher activity against Escherichia coli and Streptococcus agalactiae [24]. A new tridentate ONO donor Schiff base ligand derived from the condensation of 3-amino-2-methylquinazoline-4-one with 2-hydroxy-1-naphthaldehyde and its Cu(II), Ni(II), Co(II), Mn(II), Zn(II), and Cd(II) complexes were synthesized by Kuruba Siddappa et al The ligand and its metal complexes evaluated for their antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli [25]. Synthetic route for the preparation of ligand (figure-10) and the Proposed structure of the complexes (figure-11) are given below.…”

Section: Antibacterial Activitymentioning

confidence: 99%

Anti-pathogenic Activity of Cu(II) Complexes Incorporating Schiff Bases: A Short Review

Bitu¹,

Hossain²,

Zahid³

et al. 2019

AJHC

View full text Add to dashboard Cite

Metals contribute important roles in biological system. It is recognized that metals are highly linked in cellular and subcellular functions. With the application of novel and experienced tools to study biological and biochemical systems the true role of inorganic salts in biological systems can be studied. Schiff base metal complexes show a broad range of biological activity. The activity of Schiff base ligand is usually increased by complexation with the metal ion. The copper complexes of Schiff bases have striking properties such as antibacterial, antifungal, antiviral, anti-inflammatory, anti-tumor and cytotoxic activities, plant development controller, enzymatic activity and applications in pharmaceutical fields. The divalent cations Zn 2+, Ca 2+ and Mg 2+ prevent cytotoxicity and in vivo antagonize Cd-induced carcinogenesis. Lack of body iron is common in cancer patients and it is associated with complications in surgery and in animal experiments. The transport of iron and other metal ions by the blood plasma is achieved through the formation of protein complexes. Copper is placed as a vital metalloelement and is primarily connected with copper-dependent cellular enzymes. Metals are also used as inorganic drugs for many diseases. In this review our main focused on research undertaken for biological activity study of Cu(II) metal complexes containing Schiff bases over the past few decades.

show abstract

Spectral Characterization and 3D Molecular Modeling Studies of Metal Complexes Involving the O, N-Donor Environment of Quinazoline-4(3H)-one Schiff Base and Their Biological Studies

Cited by 21 publications

References 43 publications

Synthesis, Spectroscopic Characterization, and Biological Evaluation Studies of 5-Bromo-3-(((hydroxy-2-methylquinolin-7-yl)methylene)hydrazono)indolin-2-one and Its Metal (II) Complexes

Anti-pathogenic Activity of Cu(II) Complexes Incorporating Schiff Bases: A Short Review

Contact Info

Product

Resources

About