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Metal complexes of Schiff base 4-[(2, 4-dihydroxy-benzylidene)-amino]-1, 5-dimethyl-2-phenyl-1, 2-dihydroxo-pyrazol-3-one (H2L) derived from condensation of 2,4-dihydroxybenzaldehyde and 4-aminoantipyrine were synthesized and characterized by FT-IR spectra, elemental analysis, 1H &13C NMR, mass spectra, UV–Visible, X-ray diffraction, molar conductance, magnetic moment and thermal analysis (TGA). The elemental analysis proved that the complexes have the general formulae of [M(HL)(X)(OH2)]2, where M = Cu(II); X = OAc− (1); NO3− (2); Cl− (3), M = Co(II) (4), Mn(II) (5); X = OAc and {[UO2(HL)]2.2(OAc)}(6). According to the FT-IR spectra data, it was found that the H2L ligand is coordinated to the metal ions in a tridentate donor sites of the nitrogen atom of azomethine group, the oxygen atom of phenolic group and the oxygen atom of carbonyl group. From the measurements of magnetic susceptibility and electronic spectral data, it is found that these complexes are octahedral geometries. The trend in g value (g║ ˃ g⊥ ˃ 2.00) suggests that the unpaired electron on copper has dx2-y2 character and the complexes have an octahedral structure. By comparing the synthesized ligand (H2L) to its metal complexes was screened for their antibacterial activity against Klebsiella pneumoniae, Escherichia coli, Pseudomonas sp., Bacillus cereus and Staphylococcus aureus. It was found that the metal complexes had more potent antimicrobial than the parent Schiff base ligand against one or more microbial species. Some complexes showed higher activity than ligand. The complex (3) has antibacterial activities against Bacillus cereus, Klebsiella pneumoniae and Staphylococcus aureus. The antibacterial activity of complex (3) was the highest ones than the ligand and other complexes as well as penicillin G against Klebsiella pneumoniae. Antifungal activities were determined against Fusarium oxysporum, Aspergillus niger and Candida albicans. The inhibition efficiency of the prepared ligand (H2L) against the corrosion of carbon steel in HCl (2 M) solution was determined by various electrochemical techniques.

A series of novel Schiff base 1-((2-hydroxyphenyl)iminomethyl)naphthalene-2-ol (H2L) and its Cu(II), Co(II), Ni(II), Mn(II),Cd(II) and UO2(II) complexes were synthesized and characterized. The nature of bonding and the geometry of the complexes were deduced from elemental analysis, spectral (FT-IR, UV-Vis., 1H NMR, mass and ESR), magnetic moment, thermal analyses, X-ray diffraction and conductivity measurements. The microbial activity of the compounds was studied using disc diffusion method against bacteria, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia and Bacillus subtilis and against fungi, Aspergillus niger, Fusarium oxysporum, Alternaria alternata and Candida albicans. The results indicated that the Ni(II) complex showed the potent antibacterial activities against Staphylococcus aureus and Klebsiella pneumoniae only at 150 µg/mL. The data showed that the antifungal effect of ligand against A. niger was similar to the effect of Co(II), Mn(II), Cd(II) and UO2(II) complexes where the inhibition zone ranged from 23-26 mm at 150 µg/mL concentration .The ligand showed higher interaction value of receptor of Staphylococcus aureus (3q8u) than receptor of Escherichia coli (3t88).The inhibition process of the prepared ligand (H2L) against the corrosion of Concrete Steel Reinforcement in HCl (2 M) solution was determined by various electrochemical methods are found to be in reasonable agreement.

The levels of Total Petroleum Hydrocarbons (TPH) have been reported for ten commercially important fish species from the northwestern Gulf of Suez, Egypt. Target compounds were analytically...

Oil hydrocarbon fingerprints derived from polycyclic aromatic and aliphatic hydrocarbon were analyzed in marine organisms of various aquatic species muscles collected from 10 different sites along ...

This study represents the concentrations of 16 PAHs in a commercial aquatic species Sauridaund squamis; Euthynnus affinis; Rhabdosargus haffara; Argyrops Spinifer; Nemipterus Japonicus, Oreochromis...

This study reports the concentrations of 16 PAHs in 10 of Aquatic Species samples collected along the Gulf of Suez, Eygpt, between 2016 and 2018. Among 10 species of fish investigated, Argyrops Spi...

The corrosion hindrance of Cu in 2.0 M HNO3 solution by 2-amino-6-methyl-5-oxo-4-phenyl-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carbonitrile compound has been studied, using Potentiodynamic Polarization (PP), AC Impedance (EIS), Electrochemical Frequency Modulation (EFM) techniques. Also, EIS test was utilized to confirm the corrosion protection mechanism. 2-amino-6-methyl-5-oxo-4-phenyl-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carbonitrile compound is suggested as a mixed kind inhibitor. SEM and EDX investigations of the Cu in 2.0 M HNO3 surface revealed that assembles protect Cu from corrosion by adsorption on its surfaces by a forming coating film. Clearly, the assembled mechanisms play a role as a barrier to corrosive solution.

Water pipes and drinking water quality deterioration in distribution systems and sea water desalination impose the use of corrosion inhibitors. The protective effect of spiropyrazole derivatives against Q235 steel and its adsorption performance were examined in solution of 1 M HCl utilizing TP (Tafel polarization), electrochemical frequency modulation (EFM), and electrochemical impedance spectroscopy (EIS) tests. The outcome data from hindrance efficiency rise with the dose of inhibitor. The orders of %IE of spiropyrazole derivatives are given: (1) &gt, (2) &gt, (3).It was noted that the values of EHOMO and ELUMO dropping in order run parallel to the improvement in %IE, which support the preceding order. EIS spectra exhibited one capacitive loop and approve the protective ability. Molecular docking was utilized to get a full picture on the binding mode among spiropyrazoles derivatives and the receptor of 3tt8-hormone of crystal structure examination of Cu human insulin derivative. The morphology of protected Q235 steel was evaluated by checking electron magnifying instrument innovation with energy dispersive X-beam spectroscopy (SEM&ndash, EDX).

Mixed ligand complexes of Cu(II), Co(II), Ni(II), Mn(II) and Cd(II) with N,N'-1,4-phenylene (2-hyboxynaphthaliden imine) (H2L) as primary ligand and 4-aminoantipyrine (4-AAp) as secondary ligand have been prepared. The newly formed complexes were characterized using elemental analysis, magnetic susceptibility, molar conductance, 1H NMR, UV–Vis., FTIR, X-ray diffraction, mass, thermal analysis and ESR techniques. The elemental analysis, data reveal the formation of [2:1:2] [M: H2L: 4-AAP] complexes. The mode of bonding between Cu(II), Ni(II), Co(Il), Mn(II) and Cd(II) and ligands has been studied by IR spectrophotometry. Electronic absorption spectra and magnetic moment measurements of the mixed-ligand complexes suggest a distorted octahedral geometry around the central metal ion and the anions X− are in the axial positions, for all compounds. The ligands are found to behave in a neutral bidentate manner, through nitrogen atom and oxygen atom of carbonyl group (secondary ligand), whereas H2L (primary ligand) coordinated through nitrogen and OH group as a neutral ligand. FT-IR spectral data shows that the ligand acted as bis-bidentate coordination through ON–NO donor system. The XRD patterns of the ligand and its mixed ligand complexes showed the polycrystalline natures. The ligand and its mixed complexes were studied for their microbial activity against some bacteria and fungi. The ligand in comparison to its mixed ligand complexes (1-5) was screened for their antibacterial activity against Klebsiella pneumoniae, Escherichia coli, Pseudomonas sp., Staphylococcus aureus and Bacillus cereus. Antifungal activities of ligand in comparison to its mixed ligand complexes (1-5) were determined against Fusarium oxysporum, Aspergillus niger and Candida albicans. It was found that the mixed ligand complex (5) is more active than other mixed ligand complexes and penicillin G against Bacillus cereus, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas sp. The mixed ligand complex (5) is more active than the ligand and other mixed ligand complexes and miconazole against Aspergillus niger. The inhibition efficiency of the prepared ligand (H2L) against the corrosion of P355 carbon steel in HCl (2 M) solution was determined by various electrochemical methods are found to be in reasonable agreement. The morphology of protected P355 carbon steel was test by energy dispersive X-ray and scanning electron microscope (EDX–SEM).

The protection influence of 8-hydroxy-7-quinolinecarboxaldehyde derivatives against C-steel corrosion was studied in 2 mol·L − 1 HCl solutions at 30 °C. Measurements were conducted under various experimental conditions using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. These studies have shown that 8-hydroxy-7-quinolinecarboxaldehyde derivatives are very good “green”, mixed-type inhibitors. Corrosion rates obtained from both EFM and EIS methods are comparable with those recorded using Tafel extrapolation method, confirming validation of corrosion rates measured by the latter. The inhibitive action of these 8-hydroxy-7-quinolinecarboxaldehyde derivatives was discussed in terms of blocking the electrode surface by adsorption of the molecules through the active centers contained in their structures following Langmuir adsorption isotherm. Quantum chemical method was also employed to explore the relationship between the inhibitor molecular properties and its protection efficiency.

Schiff base ligand 4-((pyridin-2- yl)methyleneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one (PDMP) and its complexes were prepared and characterized on the basis of elemental analysis, IR, mass spectra and thermogravimetric analysis. All results confirm that the complexes have 1:1 (M: PMDP) stoichiometric formula [M(PMDP)Cl2H2O ] (M = Cu(II), Co(II), Ni(II) and Mn(II)), [Cd(PMDP)Cl2] and the ligand behaves as a bi/tridentate forming five-membered chelating ring towards the metal ions, bonding through azomethine nitrogen/exocyclic carbonyl oxygen, azomethine pyridine nitrogen and exocyclic carbonyl oxygen. The shift in the band positions of the groups involved in coordination has been utilized to estimate the metal-nitrogen and/or oxygen bond lengths. The complexes of Co(II), Ni(II) and Cu(II) are paramagnetic and the magnetic as well as spectral data suggest octahedral geometry, whereas the Cd(II) complex is tetrahedral. The XRD studies show that both the ligand and its metal complexes (1 and 3) show polycrystalline with crystal structure. Molecular docking was used to predict the binding between PMDP ligand and the receptors. The corrosion inhibition of mild steel in 2 M HCl solution by PDMP was explored utilizing potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and (EFM) electrochemical frequency modulation method. Potentiodynamic polarization demonstrated that PDMP compound is mixed-type inhibitor. EIS spectra exhibit one capacitive loop and confirm the protective ability. The percentage of inhibition efficiency was found to increase with increasing the inhibitor concentration.

An interesting azodye heterocyclic ligand of copper(II), cobalt(II), nickel(II) and uranyl(II) complexes have been synthesized by the reaction of metal salts with 5-(2,3-dimethyl-1-phenylpyrazol-5-one azo)-2-thioxo-4-thiazolidinone (HL) yields 1:1 and 1:2 (M:L) complexes depending on the reaction conditions. The elemental analysis, magnetic moments, spectral (UV–Vis, IR, 1H and 13C NMR and ESR) and thermal studies were used to characterize the isolated complexes. The molecular structures of the ligand tautomers are optimized theoretically and the quantum chemical parameters are calculated. The IR spectra showed that the ligand (HL) act as monobasic tridentate/neutral bidentate through the ( N N), enolic (C O)− and/or oxygen keto moiety groups forming a five/six-membered structures. According to intramolecular hydrogen bond leads to increasing of the complexes stability. The molar conductivities show that all the complexes are non-electrolytes. The ESR spectra indicate that the free electron is in dxy orbital. The calculated bonding parameter indicates that in-plane σ-bonding is more covalent than in-plane π-bonding. The coordination geometry is five/six-coordinated trigonal bipyramidal for complex (1) and octahedral for complexes (2–6). The value of covalency factor β12 and orbital reduction factor K accounts for the covalent nature of the complexes. The activation thermodynamic parameters are calculated using Coats–Redfern and Horowitz–Metzger methods. The synthesized ligand (HL) and its Cu(II) complexes (1, 2 and 4) are screened for their biological activity against bacterial and fungal species. The ligand (HL) showed antimicrobial activities against Escherichia coli. The ligand (HL) and its Cu(II) complexes (2 and 4) have very high antifungal activity against Penicillium italicum. The inhibitive action of ligand (HL), against the corrosion of C-steel in 2 M HCl solution has been investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS).

Rates of corrosion for copper were monitored in aerated stagnant 2 M HNO3 solutions at different temperatures (25-55 °C) using Tafel extrapolation method, electrochemical impedance spectroscopy technique, non-destructive electrochemical frequency modulation (EFM) technique and weight-loss method, accompanied by EDX examinations, molecular docking, molecular dynamics, and quantum chemical calculations. Some spiropyrazoles derivatives were introduced as corrosion-safe inhibitors. Compound (1) has the best inhibition activity (89.9% at 11 × 10−6M). Tafel plots indicated that these compounds acted mainly as mixed-type inhibitors. The inhibition process was ascribed to the formation of an adsorbed film on the copper surface that protects the metal against corrosive agents. EDX examinations of the electrode surface confirmed the existence of such adsorbed film. The inhibition efficiency increased by increasing the concentration of spiropyrazoles compounds, while it decreased by increasing the temperature, this expresses on the physical adsorption. Activation energy has been calculated in the existence and nonexistence of a number of concentrations from spiropyrazoles derivatives by measuring the corrosion rate obtained from the weight loss method at different temperatures. It was found that the activation energy in the presence of spiropyrazoles derivatives is higher than that in 2 M HNO3 solution alone. The adsorptive behavior of spiropyrazoles compounds followed Freundlich -type isotherm.

The Cu2+, Co2+, Ni2+ and UO22+ polymer complexes of 5-(2,3-dimethyl−1-phenylpyrazol-5-one azo)-8-hydroxyquinoline (HL) ligand were prepared and characterized. Elemental analyses, IR spectra, X-ray diffraction analysis and thermal analysis studies have been used to confirm the structure of the prepared polymer complexes. The chemical structure of metal chelates commensurate that the ligand acts as a neutral bis(bidentate) by through four sites of coordination (azo dye nitrogen, carbonyl oxygen, phenolic oxygen and hetero nitrogen from pyridine ring). The molecular and electronic structures of the hydrogen bond conformers of HL ligand were optimized theoretically and the quantum chemical parameters were calculated. Elemental analysis data suggested that the polymer complexes have composition of octahedral geometry for all the polymer complexes. Molecular docking of the binding between HL and the receptors of prostate cancer (PDB code 2Q7L Hormone) and the breast cancer (PDB code 1JNX Gene regulation) was studied. The interaction between HL and its polymer complexes with the calf thymus DNA (CT-DNA) was determined by absorption spectra. The antimicrobial activity of HL and its Cu2+, Co2+, Ni2+ and UO22+ polymer complexes were investigated; only Cu(II) polymer complex (1) was specifically active against Aspergillus niger. It inhibited the fungal sporulation and distorted the fungal mycelia, which became squashed at a concentration of 150 μg/ml; transmission electron microscope (TEM) also showed a deactivation of autophagy in the treated A. niger cells via accumulation of autophagic bodies in vacuoles. The inhibition process of the prepared ligand (HL) against the corrosion of carbon steel in 2 M HCl solution was determined by various methods (weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques) are found to be in reasonable agreement. The mechanism of inhibition in presence of HL in carbon steel corrosion obeys Friendlish adsorption isotherm.