Synthesis, characterization, DFT calculations and biological studies of Mn(II), Fe(II), Co(II) and Cd(II) complexes based on a tetradentate ONNO donor Schiff base ligand

El‐Khatib

et al. 2017

Applied Organom Chemis

Three novel nanosized Cu(II), Co(II) and Ni(II) complexes of imine ligand attained from the condensation of 2‐amino‐3‐hydroxypyridine and 3‐methoxysalicylaldehyde have been prepared and investigated using diverse chemical methods such as NMR, CHN analysis, conductance, IR, Spectral studies, TGA and magnetic moment measurements. The obtained data confirmed that the synthesized complexes have metal: ligand ratio of 1:1 and octahedral geometry for Co(II) and Ni(II) complexes. Interestingly, The complexes are used as precursors for producing CuO, Co2O3 and NiO nanoparticles by calcination at 500 °C and their structures were described by powder x‐ray and transmittance electron microscopy. Furthermore, to investigate the feasibility of using the synthesized materials for semiconductor based nanodevices, the electrical properties of the prepared imine complexes and their corresponding metal oxides were investigated by measuring the electrical conductivity over a temperature range 373‐593 K. The data confirm that the materials are semiconductor. The electrical conduction process in the complexes is governed by intermolecular and intramolecular transfer of the charge carriers. But, the conduction mechanism arises from the contribution of the phonon‐assisted small polaron hopping in NiO nanoparticles and charge carrier hopping in CuO and Co2O3 nanoparticles. The results indicate that the complexes under study are promising candidates for wide scale of organic based semiconducting devices.

Section: Resultsmentioning

confidence: 99%

Sonochemical synthesis, structural inspection and semiconductor behavior of three new nano sized Cu(II), Co(II) and Ni(II) chelates based on tri‐dentate NOO imine ligand as precursors for metal oxides

Rahman

El‐Khatib

et al. 2017

Applied Organom Chemis

“…The molar ratio and continuous variation methods were utilized to estimate the equilibria in solutions and the metal‐to‐ligand ratio.…”

Section: Methodsmentioning

confidence: 99%

“…The formation constants ( K f ) of the imine chelates which formed in solution were acquired from spectrophotometric estimations by way of utilizing the continuous variation route according to the following expression:

K_{f} = \frac{A / A_{m}}{{(1 - A / A_{m})}^{2} C}

where C is the initial molar concentration of the metal, A are the arbitrarily chosen absorbance values on either side of the absorbance mountain col (pass) and A m is the absorbance at the maximum formation of the complex. Also, the free energy change Δ( G * ) of the investigated metal chelates was assessed using Δ( G * ) = − RT ln K f , at 25°C, where T is the temperature in kelvin, K f is the formation constant and R is the gas constant.…”

Section: Methodsmentioning

confidence: 99%

Some new Ag(I), VO(II) and Pd(II) chelates incorporating tridentate imine ligand: Design, synthesis, structure elucidation, density functional theory calculations for DNA interaction, antimicrobial and anticancer activities and molecular docking studies

Abdel‐Rahman

Shehata

et al. 2019

Applied Organom Chemis

Self Cite

111

Some new complexes derived from VO(II), Ag(I) and Pd(II) metal ions and HNA imine ligand (L), i.e. (2‐((6‐allylidene‐2‐hydroxycyclohexa‐1,3‐dienylmethylene)amino)benzoic acid), have been prepared and their structures elucidated via molar conductance measurements, elemental analyses, infrared, NMR and electronic spectra and magnetic susceptibility estimations. Moreover, stability constants of the synthesized complexes were evaluated utilizing a spectrophotometric technique. On the basis of molar conductance and elemental analyses, the metal imine chelates have structure [M(L)], where M = Pd(II), VO(II) and Ag(I). The results indicate that the prepared HNA imine ligand acts as a tridentate moiety via nitrogen atom of azomethine group and two oxygen atoms of phenolic and carboxylic groups. All the complexes are found to be monomeric with 1:1 stoichiometry with square planar geometry for Pd(II), tetrahedral geometry for Ag(I) and distorted square pyramidal for VO(II). Theoretical density functional theory calculations were applied to verify the molecular geometry of the chelators and their metal chelates. The geometry optimization results are in agreement with experimental observations. The antimicrobial properties of the prepared HNA imine ligand and its metal chelates were evaluated against numerous plant pathogenic fungi and bacteria. The results of these studies indicate that the metal complexes exhibit a stronger antibacterial and antifungal effect compared to the imine ligand. In addition, the interaction of the metal imine chelates with calf thymus DNA was observed by way of viscosity, gel electrophoreses and spectral studies. Absorption titration studies reveal that each of the complexes is an avid binder to calf thymus DNA. Also, there are appreciable changes in the relative viscosity of DNA, which are consistent with enhanced hydrophobic interaction of the aromatic rings and intercalation mode of binding. Additionally, the cytotoxic activity of the investigated compounds against various cancer cell lines shows promising results which makes them prospective compounds for antibiotic and anticancer medicament studies. Furthermore, docking studies of the prepared compounds were conducted for confirming the biological results.

“…In biology, vanadium ions also play a substantial part as counterions for protein (DNA and RNA). The oxyvanadyl Schiff base chelates are of interest as an inhibitor of protein‐tyrosine phosphatase 1B and DNA interacting reagents, as previously reported . Although a large amount of information is reported on the coordination chemistry of Schiff bases with a variety of metal ions and their biological activities, little is known about bidentate NO imine ligand and their complexes.…”

Section: Introductionmentioning

confidence: 80%

Novel azomethine Pd (II)‐ and VO (II)‐based metallo‐pharmaceuticals as anticancer, antimicrobial, and antioxidant agents: Design, structural inspection, DFT investigation, and DNA interaction

J of Physical Organic Chem

Abdel‐Rahman

Shehata

et al. 2019

The new NO bidentate imine ligand, namely, (2‐[(3‐nitro‐benzylidene)‐amino]‐benzoic acid) (NBA) imine ligand (L), and its Pd (II) and VO (II) complexes have been synthesized and characterized by utilizing different physiochemical methods including elemental analyses, Fourier transform infrared (FT‐IR), nuclear magnetic resonance (NMR), molar conductance, and magnetic susceptibility measurements. The stability constant of these complexes has also been determined. In studies of these complexes, they were found to have [M(L)] composition where the ligand acts as a bidentate and coordinates with the various metal ions through azomethine and one oxygen atom. Moreover, the suggested geometrical structure of Pd (II) and VO (II) complexes is square planar and a distorted square pyramid, respectively. Density functional theory (DFT) calculations for the different metal complexes were studied and show a good agreement with the experiment data. The minimum inhibitory concentration method has been applied to evaluate the in vitro antimicrobial activity. Furthermore, the interaction of calf thymus DNA with the metal‐imine chelates has been assessed, and Pd (II) complex showed the strongest interaction with DNA for a binding constant value of (9.72 × 104 kcal mol−1). The cytotoxic activity of the new metal chelates has been evaluated against three human cancer cell lines (hepatic carcinoma HepG2 cells, breast carcinoma cells MCF‐7, and colon carcinoma cells HCT‐116). It has found that NBAPd complex exhibited a significant decrease in the time and dose of the cell viability than did the reference drug vinblastine. The antioxidant activity of the tested compounds was determined and compared with that of vitamin C as a standard drug. It has been found that the metal complexes exhibit higher activity than the free ligand. The finding from this investigation revealed that the new compounds are considered to be prospective antibiotic and anticancer agents.