Greener solid state synthesis of nano-sized mono and homo bi-nuclear Ni(II), Co(II), Mn(II), Hg(I... more Greener solid state synthesis of nano-sized mono and homo bi-nuclear Ni(II), Co(II), Mn(II), Hg(II), Cd(II) and Zn(II) complexes with new sulfa ligand as a potential antitumour and antimicrobial agents New nano-sized mono and homo bi-nuclear Ni(II), Co(II), Mn(II), Hg(II), Cd(II) and Zn(II) complexes with 4-[(2-hydroxybenzylidene)amino]-N-(1,3-thiazol-2-yl)benzenesulfonamide (H 2 L) were synthesized by solid-solid reaction at room temperature. The complexes were structurally characterized using MS, FT-IR, UV–Vis, ESR, 1 H and 13 C NMR, spectra, thermal analyses, X-ray powder diffraction, SEM, conductance and magnetic measurements. FT-IR and NMR studies denoted that H 2 L coordinates to the metallic centers in a di-basic tetra-dentate mode using both the Schiff base center and the sulfonamide part. UV–Vis, ESR spectra and thermo-gravimetric analysis revealed that whole complexes attain tetrahedral geometry. Coats-Redfern method was applied in calculating the activation thermo-kinetic parameters (E*, ΔH*, ΔS*, and ΔG*) for the diverse thermal decomposition stages from TGA curves. The data obtained from XRD and SEM images unequivocally asserted the nano-sized metal che-lates. The inspected structures were propped using 3-D molecular modeling of some complexes employing molecular mechanics (MM +) and semi-empirical molecular orbital calculations (PM3). The recently inspected compounds were scrutinized for antimicrobial activities towards assorted species of bacteria and fungi. Also, the anticancer efficiency versus human liver Carcinoma cell line (HEPG2) was examined. The results are very promising for their enforcements in therapeutic uses.
To enhance growing societal and industrial energy demands in an environmentally friendly pathway,... more To enhance growing societal and industrial energy demands in an environmentally friendly pathway, will appeal the use of clean energy sources such as wind, nuclear, solar, electric batteries, etc. Lithium-ion rechargeable batteries offer energy conversion and storage devices with long life and high energy density suitable for varied novel applications such as electric and hybrid vehicles. In this work, pristine lithium manganese oxide (LiMn 2 O 4) and La 3+ , Zr 4+ double doped Nano lithium manganates (LiMn 2 − 2X La X Zr X O 4 , x = 0.02%, 0.04%] were synthesized by solid state method for rechargeable Li-ion batteries applications. The resulting spinel products were exposed to both fast and thermal neutrons irradiations. The effects of the dopant cations and irradiation process on the structure profile and DC-electrical conductivity of the spinels were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared (IR) spectroscopy. The obtained results denote that the investigated samples can be used as solid detectors for thermo neutrons irradiation. Direct-current (DC) electrical conductivity studies revealed that LiMn 2 O 4 , LiMn 1.96 La 0.02 Zr 0.02 O 4 and LiMn 1.92 La 0.04 Zr 0.04 O 4 Nano spinels are semicon-ducting and their activation energies decrease with increasing La 3+ and Zr 4+ dopant contents.
A series of new homo-binuclear nano Mn(II), Fe (III), Co(II), Ni(II), and Cu(II) complexes were s... more A series of new homo-binuclear nano Mn(II), Fe (III), Co(II), Ni(II), and Cu(II) complexes were synthesized using a Schiff base ligand derived by condensation of p-phenylenediamine with 2-hydroxy-1-naphthaldehyde. The prepared complexes were characterized using elemental , thermal analyses, FTIR, 1 HNMR, 13 CNMR, UV–Vis, XRD, SEM, molar conductance, and magnetic moment measurements. FTIR spectral studies revealed the interaction of the ligand as bi-negative tetra-dentate towards Mn(II) and Fe(III) atoms, whereas the ligand molecule coordinates in neutral tetra-dentate mode towards Co(II), Ni(II), and Cu (II) ions. The geometries proposed are mainly octahedral configuration surrounds the central atoms referring to the electronic spectral data and magnetic measurements. The calculations abstracted from XRD patterns propose the nano-sized complexes. The SEM images show the nano-sized appearance of the particles except for the Ni(II)-complex. Thermo-gravimetric analysis was used to ensure the nature of the presence of solvent molecules attaching to the complexes. Molecular modeling was performed to assert the structural formula proposed for the ligand and some of its complexes. Also, drug-likeness was theoretically estimated to display the probable biological activity of the free ligand through a theoretical comparison with known drugs.
New liquid membrane electrodes for submicromolar determination of praepagen HYCl surfactant have ... more New liquid membrane electrodes for submicromolar determination of praepagen HYCl surfactant have been prepared. These electrodes utilize HYCl with phosphotungstic acid (PTA) as ion-pair (HY–PT) dissolved in the plasticizers: dibutyl phthalate (DBP) encoded sensor S1, dioctyl phthalate (DOP) encoded sensor S2, dioctylsebacate (DOS) encoded sensor S3 and tris(2-ethylhexyl) phosphate (TOPh) encoded sensor S4. The proposed electrodes exhibit Nernstian slopes of 59.5 ± 0.6, 58.5 ± 0.6, 55.2 ± 0.6 and 57.3 ± 0.5 mV/decade in the concentration ranges 1.0 × 10− 7–1.0 × 10− 2, 2.5 × 10− 8–1.0 × 10− 2, 8.0 × 10− 8–1.0 × 10− 2 and 1.0 × 10− 7–1.0 × 10− 2 M and notably low limits of detection: 1.0 × 10− 7, 2.0 × 10− 8, 3.5 × 10− 8 and 8.5 × 10− 8 M for sensors S1, S2, S3 and S4 respectively. The sensors have considerably short response times (5–10 s) and good repeatability within the pH range 2.8–9.4. The electrodes exhibit excellent selectivity for HY+ ions over many inorganic and organic cations. These electrodes are useful for determination of HYCl in shampoo and liquid detergent solutions as proved by standard addition and the calibration curve methods. Furthermore, the successful use as indicator electrode was culminated by the potentiometric titration of HY+ ions in water samples.
A series of metal complexes was synthesized using a simple thiourea derivative. The prepared comp... more A series of metal complexes was synthesized using a simple thiourea derivative. The prepared complexes were characterized using different techniques (FTIR, ESR, X-ray diffraction [XRD], TG/ DTA, and TEM). The FTIR spectrum of the ligand shows the presence of its tautomer forms (keto– enol). The ligand coordinates as a neutral bidentate in the Pt(IV), Pd(II), and Pt(II) complexes. In the case of Co(II) and Ni(II) complexes, the ligand is mono-negative bidentate. The proposed com- plexes are four to six coordinate. The geometries are proposed based on electronic spectral data and magnetic measurements and were verified using other tools. The XRD patterns reflect the nanocrystalline structures except for the Cu(II) complex, which is amorphous. The TEM images for platinum complexes show nanosize particles and homogeneous metal ion distribution on the com- plex surface. The EPR spectrum of Cu(II) complex verified the octahedral geometry of the complex. Molecular modeling was performed to assign the structural formula proposed for the ligand based on the characterization results.
Two azo-azomethine ligands with N2O2 donor atom sets and their binuclear UO2(II)-complexes were s... more Two azo-azomethine ligands with N2O2 donor atom sets and their binuclear UO2(II)-complexes were synthesized for therapeutic uses. The ligands were derived from the condensation of 4-(4-hydroxy-3-formyl-1-ylazo)-N-pyrimidin-2-yl-benzenesulfonamide with ethylenediamine and 1,6-hexanediamine. The prepared ligands and their bi-homonuclear uranyl complexes were characterized by thermal analyses (TGA & conventional method), vibrational, electronic, 1 H NMR, and mass spectra as well as by different physicochemical techniques. The active coordination centers in the ligands and the geometrical arrangement of the complexes were investigated using the spectral data. Molar conductance measurements in DMSO solution denoted that the complexes are non-electrolytes. The investigated complexes and ligands were screened in vitro for their antimicrobial activity against fungi (Aspergillus flavus and Candida albicans), gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). It was observed that the complexes are more potent fungicides and bactericides than the ligands.
Holothuria polii (Delle Chiaje, 1823) (Holothuriidae) is a sea cucumber inhabiting Mediterranean ... more Holothuria polii (Delle Chiaje, 1823) (Holothuriidae) is a sea cucumber inhabiting Mediterranean Sea coast of Egypt. The bioactive compound of its tegument has antifungal, antibacterial and antiparasitic effects. The present study aims to elucidate the structure of the bioactive material of H. polii for pharmacological and chemotaxonomic purposes. Furthermore, the study demonstrates its efficacy as a cytotoxic agents against two tumor cell lines HCT116 (colon adenocarcinoma cell line) and MCF7 (breast adenocarcinoma cell line). The biological active compound of the ethanol extract has been characterized by means of infrared (IR), proton-nuclear magnetic resonance (1 H NMR), ultraviolet–visible (UV–Vis) and mass spectra. Protein profile was carried out using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Cytotoxic activity was carried out according to sulforhodamine-B assay. IR, 1 H NMR, UV–Vis and mass spectra showed that the extracted bioactive material is a nonsulfated hexaosides called bivittoside. This glycoside is composed of aglycone and a glycosidic chain (carbohydrate chain) enclosed with six sugar units, including xylose, glucose, 3-O-methylglucose and quinovose. There were no traces of dissolved proteins. The preliminary cytotoxic assay of bivittoside exhibited significant cytotoxic activity against two types of cultured tumor cell lines of HCT116 and MCF7. The half-maximal inhibitory concentration was 17.4 mg/ml and 18 mg/ml for MCF7 and HCT116, respectively. Although H. polii belongs to the genus Holothuria, the lacking of sulfate group and the fact that it contains up to six monosaccharides make it different from this genus. The present study suggests separation of H. polii from its genus to a new one. On the other hand, results support the hypothesis that H. polii bioactive compound has an antitumor effect.
Two sulfadiazine azo-azomethine dyes containing two active coordination centers and their bi-homo... more Two sulfadiazine azo-azomethine dyes containing two active coordination centers and their bi-homonuclear UO 2 (II)-complexes were synthesized for potential chemotherapeutic use. The ligands were prepared, starting from the coupling of sulfadiazine dizonium salt with acetylacetone, followed by condensation with ethylenediamine and 1,6-hexanediamine (HL I and HL II) using a modified literature procedure. The structures of the ligands and their UO 2 (II)-complexes were elucidated by conventional and thermal gravimetric analyses, molar conductivity, magnetic susceptibility, and IR, UV-Vis, 1 H NMR, and mass spectra. The analytical and spectral data supported the binuclear formulation of the complexes with a 2:1 metal to ligand ratio and octahedral geometry. The molar conductance values of the UO 2 (II)-complexes revealed their nonionic character. The ligands and their complexes were screened for their antibacterial activities towards the gram-positive Staphylococcus aureus and the gram-negative Escherichia coli, as well as their antifungal activities against Aspergillus niger and Candida albicans, in order to assess their antimicrobial potential. The results showed that metallization increases antimicrobial activity compared with the free ligands.
V 5+ and Cr 6+ double doped nano lithium manganese oxide spinels Li[V x Cr x Mn 2-2X ]O 4 , (x=0.... more V 5+ and Cr 6+ double doped nano lithium manganese oxide spinels Li[V x Cr x Mn 2-2X ]O 4 , (x=0.00, 0.02, 0.05 %)] were synthesized by doping the pure spinel LiMn 2 O 4 with vanadium and chromium ions as cathode materials for rechargeable batteries applications. These cathode materials were characterized by thermal gravimetric and differential thermal analysis (TG/DTA), x-ray powder diffractometry (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR) measurements. XRD and SEM studies confirmed the nano materials size for all prepared spinels. LiMn 2 O 4 and Li[V 0.05 Cr 0.05 Mn 1.9 ]O 4 spinels were irradiated by γ-irradiation (10 and 30 kGy). Direct-current (DC) electrical conductivity measurements indicated that these samples are semiconducting and their conductivity was strongly affected by the dopant cations and γ-irradiation. Keywords: lithium ion battery, vanadium and chromium co-doped spinels, γ-ray effect
A series of homobinuclear complexes of the type [M2L(NO3)n(H2O)m] where M=UO2(VI), ZrO(IV), Th(IV... more A series of homobinuclear complexes of the type [M2L(NO3)n(H2O)m] where M=UO2(VI), ZrO(IV), Th(IV); L=3-benzylidine-imino-5-p-sulphonamido phenyl azo-2-thiohyatoin(bispt), 3-furfurylidine-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(fispt),3-pyridyl-2’-methylene-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(pmispt) and 3-thienyl- 2’-methylene-imino-5-p-sulphoanamido phenyl azo-2-thiohydantoin(tmispt); n=8 for Th(IV) and 4 for others, m=4 for bispt and 3 for others have been synthesized and characterized on the basis of elemental analysis, thermal analysis, molar conductance, magnetic moment and spectroscopic data (IR, electronic and 1H-NMR). In the light of this information, the ligands can be visualized as tetradentate co-ordinating through azomethine nitrogen, carbonyl oxygen to one metal centre where as azo nitrogen and thioimido nitrogen to the other metal centre yielding homo binuclear complexes of the above composition. The fungi toxicity of the ligands & their zirconyl complexes against some fungal pathogen has been studied.
Various methods for improving the lower detection limit of polymeric membrane ion-selective elect... more Various methods for improving the lower detection limit of polymeric membrane ion-selective electrodes have been approached recently. The ion-selective electrode with solid-state membrane is described. Tetraphenyl borate as a lipophilic anion, is incorporated into the membrane of the electrode to improve its detection limit and selectivity. The detection limit was significantly lowered where nanomolar quantities were traced. Other favorable characteristics of the electrode are noticeably short response time of 5 seconds and good selectivity over the common interfering chemical species as well as its proven usefulness for determination of the surfactant in miscellaneous samples.
LiMn 2 O 4 is an attractive candidate cathode material for Li-ion rechargeable batteries, but it ... more LiMn 2 O 4 is an attractive candidate cathode material for Li-ion rechargeable batteries, but it suffers from severe capacity fading, especially at higher temperature (55 • C) during charging/discharging processes. Recently, many attempts have been made to synthesize modified LiMn 2 O 4. In this work, a new study on the synthesis of pure and U 4+-doped nano lithium manganese oxide [LiMn 2−x U x O 4 , (x = 0.00, 0.01, 0.03)] via solid-state method was introduced. The synthesized LiMn 1.97 U 0.03 O 4 was irradiated by γ-radiation (10 and 30 kGy). The green samples and the resulting spinel products were characterized using thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), infrared (IR), and scanning electron microscopy (SEM) measurements. XRD and SEM studies revealed nano-sized particles in all prepared samples. Direct-current (DC) electrical conductivity measurements indicated that these samples are semiconductors and the activation energies decrease with increasing rare-earth U 4+ content and γ-irradiation. ∆E a equals to 0.304 eV for LiMn 1.99 U 0.01 O 4 , ∆E a is 0.282 eV for LiMn 1.97 U 0.03 O 4 and decreases to ∆E a = 0.262 eV for γ-irradiated LiMn 1.97 U 0.03 O 4 nano spinel. The data obtained for the investigated samples increase their attractiveness in modern electronic technology.
Pristine lithium manganate (LiMn2O4) and Ag1+, Y3+ double doped nano lithium manganate [LiMn2−2xA... more Pristine lithium manganate (LiMn2O4) and Ag1+, Y3+ double doped nano lithium manganate [LiMn2−2xAgxYxO4, (x = 0.025, 0.05)] spinels were synthesized via a coprecipitation method for rechargeable batteries applications. The syn- thesized LiMn1.9Ag0.05Y0.05O4 was exposed to different doses of γ-irradiation (10 and 30 kGy). The resulting spinel products were characterized by using thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), electronic (UV-Vis) and electron spin resonance (ESR) spectra. LiMn2O4 exhibited a discharge capacity of 124 mAhg−1 while LiMn1.9Ag0.05Y0.05O4 had discharge capacities of 129 and 137 mAhg−1 for non irradiated and γ-irradiated (30 kGy) samples, respectively. The effects of the dopant cations and γ-irradiation on the discharge capacity and DC-electrical conductivity of some synthesized spinels were studied.
This paper introduces the development a new chemically modified carbon paste electrode (CMCPE) fo... more This paper introduces the development a new chemically modified carbon paste electrode (CMCPE) for the determination of a cationic surfactant. The paste is based on alkyl dimethyl hydroxyethyl ammonium chloride (ADHACl) with phosphomolybdic acid as an ion-exchan-ger (ADHA-PM). The electrode exhibits a Nernstian slope of 59.1 ± 0.5 mV/decade for ADHA ions in the concentration range 1.0 9 10-6 –1.0 9 10-3 M with the limit of detection of 8.2 9 10-7 M. The proposed electrode has a fast and stable response time of 5–8 s, a good reproduc-ibility and it can be used in the pH range of 2.2–9.0. Selectivity coefficients, determined by a matched potential method and separate solution method, showed high selec-tivity for ADHA over a large number of inorganic cations and organic cations. These characteristics of the electrode enable it to be used successfully for determination of ADHA in shampoo and liquid detergents solutions by standard addition and the calibration curve methods. In addition, the modified electrode was applied as an indicator electrode in potentiometric titration and successfully used to determine ADHA in water samples with satisfactory results. Keywords Alkyl dimethyl hydroxyethyl ammonium chloride Á Ion-selective electrode Á Potentiometry
A b s t r a c t Pure nano lithium manganese oxide spinel (LiMn 2 O 4) and Tb 3+ doped lithium man... more A b s t r a c t Pure nano lithium manganese oxide spinel (LiMn 2 O 4) and Tb 3+ doped lithium manganese oxide spinels [LiMn 2-xTbxO 4 , (x = 0.01%, 0.02%)] are synthesized via solid-state method. The synthesized LiMn 1.99 Tb 0.01 O 4 was irradiated by γ-irradiation with 30 kGy. The resulting spinel product is characterized by various methods such as thermo gravimetric and differential thermal analysis (TG/DTA), infrared (IR) spectroscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive of x-rays analysis (EDAX), electron spin resonances (ESR) studies and DC–electrical conductivity measurements. The XRD and SEM confirm the nano materials size for all prepared samples. DC–electrical conductivity measurements indicates that these samples are semiconductor and the activation energy decreases with increasing rare-earth Tb 3+ content; ΔE a = 0.427 eV for LiMn 1.99 Tb 0.01 O 4 , ΔE a = 0.339 eV for LiMn 1.98 Tb 0.02 O 4 and decreases to ΔE a = 0.330 eV for γ-irradiation of LiMn 1.99 Tb 0.01 O 4 nano spinel thus in role increases its attractiveness in modern electronic technology. Abou-Sekkina activation energy for the induced γ-irradiation is evaluated for the first time, which was found to be 0.097 eV.
A comparative study was made between two designs of benzalkonium ion (Bz)-selective electrodes: a... more A comparative study was made between two designs of benzalkonium ion (Bz)-selective electrodes: a silver-coated (solid contact) called electrode A and a PVC membrane (liquid inner contact) called electrode B based on benzalkonium-phosphomolybdate (Bz-PM) as ion-exchanger complex. Electrode A has a linear dynamic range from 2.0 Â 10 À 8 to 1.0 Â 10 À 2 mol L À 1 , with a Nernstian slope of 6070.3 mV/ decade and a detection limit of 2.0 Â 10 À 8 mol L À 1. Electrode B shows linearity over the concentration range from 2.0 Â 10 À 7 to 1.0 Â 10 À 2 mol L À 1 , with a Nernstian slope of 5571.2 mV/decade and a limit of detection of 1.5 Â 10 À 7 mol L À 1. Electrode A showed better performance than electrode B. The detection limit of benzalkonium chloride (BzCl) was effectively improved by a solid contact ion-selective electrode (SC-ISE), rather than the traditional liquid inner contact electrode that gives lower detection limits because of diminished ion fluxes. The present electrodes show clear discrimination of BzCl from several inorganic, organic ions, sugars and some common drug excipients. The sensors were applied efficiently for determination of BzCl in its pharmaceutical preparations (eye, ear and nasal drops) using standard addition and the calibration curve methods.
New mono-and binuclear copper(II) complexes with Schiff bases derived from the condensation of 2-... more New mono-and binuclear copper(II) complexes with Schiff bases derived from the condensation of 2-amino-5-substituted-aryl-1,3,4-thiadiazole with substituted aryl aldehydes were synthesized. The complexes were characterized by elemental analyses, molar conductivity, magnetic moment, IR, 1 H NMR, electronic, ESR and mass spectrometry as well as thermal analyses. The conductivity data of the complexes confirmed their non-electrolytic nature. An octahedral geometry was suggested for complex 1, square-planar geometry proposed for complex 2 and square pyramidal structure suggested for complexes 3-7. The 3D molecular modeling of a representative complex was carried out on a CS Chem 3-D Ultra Molecular Modeling and Analysis Program. The synthesized complexes and ligands were screened in-vitro for their antimicrobial activity against gram-positive bacteria (Staphylococcus aureus), gram-negative bacteria (Escherichia coli) and fungi (Aspergillus flavus and Candida albicans). In most cases, metallation increased the antimicrobial activity compared with the free ligands. Also, the catalytic effect of the prepared complexes on the cathodic reduction of oxygen was studied.
Greener solid state synthesis of nano-sized mono and homo bi-nuclear Ni(II), Co(II), Mn(II), Hg(I... more Greener solid state synthesis of nano-sized mono and homo bi-nuclear Ni(II), Co(II), Mn(II), Hg(II), Cd(II) and Zn(II) complexes with new sulfa ligand as a potential antitumour and antimicrobial agents New nano-sized mono and homo bi-nuclear Ni(II), Co(II), Mn(II), Hg(II), Cd(II) and Zn(II) complexes with 4-[(2-hydroxybenzylidene)amino]-N-(1,3-thiazol-2-yl)benzenesulfonamide (H 2 L) were synthesized by solid-solid reaction at room temperature. The complexes were structurally characterized using MS, FT-IR, UV–Vis, ESR, 1 H and 13 C NMR, spectra, thermal analyses, X-ray powder diffraction, SEM, conductance and magnetic measurements. FT-IR and NMR studies denoted that H 2 L coordinates to the metallic centers in a di-basic tetra-dentate mode using both the Schiff base center and the sulfonamide part. UV–Vis, ESR spectra and thermo-gravimetric analysis revealed that whole complexes attain tetrahedral geometry. Coats-Redfern method was applied in calculating the activation thermo-kinetic parameters (E*, ΔH*, ΔS*, and ΔG*) for the diverse thermal decomposition stages from TGA curves. The data obtained from XRD and SEM images unequivocally asserted the nano-sized metal che-lates. The inspected structures were propped using 3-D molecular modeling of some complexes employing molecular mechanics (MM +) and semi-empirical molecular orbital calculations (PM3). The recently inspected compounds were scrutinized for antimicrobial activities towards assorted species of bacteria and fungi. Also, the anticancer efficiency versus human liver Carcinoma cell line (HEPG2) was examined. The results are very promising for their enforcements in therapeutic uses.
To enhance growing societal and industrial energy demands in an environmentally friendly pathway,... more To enhance growing societal and industrial energy demands in an environmentally friendly pathway, will appeal the use of clean energy sources such as wind, nuclear, solar, electric batteries, etc. Lithium-ion rechargeable batteries offer energy conversion and storage devices with long life and high energy density suitable for varied novel applications such as electric and hybrid vehicles. In this work, pristine lithium manganese oxide (LiMn 2 O 4) and La 3+ , Zr 4+ double doped Nano lithium manganates (LiMn 2 − 2X La X Zr X O 4 , x = 0.02%, 0.04%] were synthesized by solid state method for rechargeable Li-ion batteries applications. The resulting spinel products were exposed to both fast and thermal neutrons irradiations. The effects of the dopant cations and irradiation process on the structure profile and DC-electrical conductivity of the spinels were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared (IR) spectroscopy. The obtained results denote that the investigated samples can be used as solid detectors for thermo neutrons irradiation. Direct-current (DC) electrical conductivity studies revealed that LiMn 2 O 4 , LiMn 1.96 La 0.02 Zr 0.02 O 4 and LiMn 1.92 La 0.04 Zr 0.04 O 4 Nano spinels are semicon-ducting and their activation energies decrease with increasing La 3+ and Zr 4+ dopant contents.
A series of new homo-binuclear nano Mn(II), Fe (III), Co(II), Ni(II), and Cu(II) complexes were s... more A series of new homo-binuclear nano Mn(II), Fe (III), Co(II), Ni(II), and Cu(II) complexes were synthesized using a Schiff base ligand derived by condensation of p-phenylenediamine with 2-hydroxy-1-naphthaldehyde. The prepared complexes were characterized using elemental , thermal analyses, FTIR, 1 HNMR, 13 CNMR, UV–Vis, XRD, SEM, molar conductance, and magnetic moment measurements. FTIR spectral studies revealed the interaction of the ligand as bi-negative tetra-dentate towards Mn(II) and Fe(III) atoms, whereas the ligand molecule coordinates in neutral tetra-dentate mode towards Co(II), Ni(II), and Cu (II) ions. The geometries proposed are mainly octahedral configuration surrounds the central atoms referring to the electronic spectral data and magnetic measurements. The calculations abstracted from XRD patterns propose the nano-sized complexes. The SEM images show the nano-sized appearance of the particles except for the Ni(II)-complex. Thermo-gravimetric analysis was used to ensure the nature of the presence of solvent molecules attaching to the complexes. Molecular modeling was performed to assert the structural formula proposed for the ligand and some of its complexes. Also, drug-likeness was theoretically estimated to display the probable biological activity of the free ligand through a theoretical comparison with known drugs.
New liquid membrane electrodes for submicromolar determination of praepagen HYCl surfactant have ... more New liquid membrane electrodes for submicromolar determination of praepagen HYCl surfactant have been prepared. These electrodes utilize HYCl with phosphotungstic acid (PTA) as ion-pair (HY–PT) dissolved in the plasticizers: dibutyl phthalate (DBP) encoded sensor S1, dioctyl phthalate (DOP) encoded sensor S2, dioctylsebacate (DOS) encoded sensor S3 and tris(2-ethylhexyl) phosphate (TOPh) encoded sensor S4. The proposed electrodes exhibit Nernstian slopes of 59.5 ± 0.6, 58.5 ± 0.6, 55.2 ± 0.6 and 57.3 ± 0.5 mV/decade in the concentration ranges 1.0 × 10− 7–1.0 × 10− 2, 2.5 × 10− 8–1.0 × 10− 2, 8.0 × 10− 8–1.0 × 10− 2 and 1.0 × 10− 7–1.0 × 10− 2 M and notably low limits of detection: 1.0 × 10− 7, 2.0 × 10− 8, 3.5 × 10− 8 and 8.5 × 10− 8 M for sensors S1, S2, S3 and S4 respectively. The sensors have considerably short response times (5–10 s) and good repeatability within the pH range 2.8–9.4. The electrodes exhibit excellent selectivity for HY+ ions over many inorganic and organic cations. These electrodes are useful for determination of HYCl in shampoo and liquid detergent solutions as proved by standard addition and the calibration curve methods. Furthermore, the successful use as indicator electrode was culminated by the potentiometric titration of HY+ ions in water samples.
A series of metal complexes was synthesized using a simple thiourea derivative. The prepared comp... more A series of metal complexes was synthesized using a simple thiourea derivative. The prepared complexes were characterized using different techniques (FTIR, ESR, X-ray diffraction [XRD], TG/ DTA, and TEM). The FTIR spectrum of the ligand shows the presence of its tautomer forms (keto– enol). The ligand coordinates as a neutral bidentate in the Pt(IV), Pd(II), and Pt(II) complexes. In the case of Co(II) and Ni(II) complexes, the ligand is mono-negative bidentate. The proposed com- plexes are four to six coordinate. The geometries are proposed based on electronic spectral data and magnetic measurements and were verified using other tools. The XRD patterns reflect the nanocrystalline structures except for the Cu(II) complex, which is amorphous. The TEM images for platinum complexes show nanosize particles and homogeneous metal ion distribution on the com- plex surface. The EPR spectrum of Cu(II) complex verified the octahedral geometry of the complex. Molecular modeling was performed to assign the structural formula proposed for the ligand based on the characterization results.
Two azo-azomethine ligands with N2O2 donor atom sets and their binuclear UO2(II)-complexes were s... more Two azo-azomethine ligands with N2O2 donor atom sets and their binuclear UO2(II)-complexes were synthesized for therapeutic uses. The ligands were derived from the condensation of 4-(4-hydroxy-3-formyl-1-ylazo)-N-pyrimidin-2-yl-benzenesulfonamide with ethylenediamine and 1,6-hexanediamine. The prepared ligands and their bi-homonuclear uranyl complexes were characterized by thermal analyses (TGA & conventional method), vibrational, electronic, 1 H NMR, and mass spectra as well as by different physicochemical techniques. The active coordination centers in the ligands and the geometrical arrangement of the complexes were investigated using the spectral data. Molar conductance measurements in DMSO solution denoted that the complexes are non-electrolytes. The investigated complexes and ligands were screened in vitro for their antimicrobial activity against fungi (Aspergillus flavus and Candida albicans), gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). It was observed that the complexes are more potent fungicides and bactericides than the ligands.
Holothuria polii (Delle Chiaje, 1823) (Holothuriidae) is a sea cucumber inhabiting Mediterranean ... more Holothuria polii (Delle Chiaje, 1823) (Holothuriidae) is a sea cucumber inhabiting Mediterranean Sea coast of Egypt. The bioactive compound of its tegument has antifungal, antibacterial and antiparasitic effects. The present study aims to elucidate the structure of the bioactive material of H. polii for pharmacological and chemotaxonomic purposes. Furthermore, the study demonstrates its efficacy as a cytotoxic agents against two tumor cell lines HCT116 (colon adenocarcinoma cell line) and MCF7 (breast adenocarcinoma cell line). The biological active compound of the ethanol extract has been characterized by means of infrared (IR), proton-nuclear magnetic resonance (1 H NMR), ultraviolet–visible (UV–Vis) and mass spectra. Protein profile was carried out using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Cytotoxic activity was carried out according to sulforhodamine-B assay. IR, 1 H NMR, UV–Vis and mass spectra showed that the extracted bioactive material is a nonsulfated hexaosides called bivittoside. This glycoside is composed of aglycone and a glycosidic chain (carbohydrate chain) enclosed with six sugar units, including xylose, glucose, 3-O-methylglucose and quinovose. There were no traces of dissolved proteins. The preliminary cytotoxic assay of bivittoside exhibited significant cytotoxic activity against two types of cultured tumor cell lines of HCT116 and MCF7. The half-maximal inhibitory concentration was 17.4 mg/ml and 18 mg/ml for MCF7 and HCT116, respectively. Although H. polii belongs to the genus Holothuria, the lacking of sulfate group and the fact that it contains up to six monosaccharides make it different from this genus. The present study suggests separation of H. polii from its genus to a new one. On the other hand, results support the hypothesis that H. polii bioactive compound has an antitumor effect.
Two sulfadiazine azo-azomethine dyes containing two active coordination centers and their bi-homo... more Two sulfadiazine azo-azomethine dyes containing two active coordination centers and their bi-homonuclear UO 2 (II)-complexes were synthesized for potential chemotherapeutic use. The ligands were prepared, starting from the coupling of sulfadiazine dizonium salt with acetylacetone, followed by condensation with ethylenediamine and 1,6-hexanediamine (HL I and HL II) using a modified literature procedure. The structures of the ligands and their UO 2 (II)-complexes were elucidated by conventional and thermal gravimetric analyses, molar conductivity, magnetic susceptibility, and IR, UV-Vis, 1 H NMR, and mass spectra. The analytical and spectral data supported the binuclear formulation of the complexes with a 2:1 metal to ligand ratio and octahedral geometry. The molar conductance values of the UO 2 (II)-complexes revealed their nonionic character. The ligands and their complexes were screened for their antibacterial activities towards the gram-positive Staphylococcus aureus and the gram-negative Escherichia coli, as well as their antifungal activities against Aspergillus niger and Candida albicans, in order to assess their antimicrobial potential. The results showed that metallization increases antimicrobial activity compared with the free ligands.
V 5+ and Cr 6+ double doped nano lithium manganese oxide spinels Li[V x Cr x Mn 2-2X ]O 4 , (x=0.... more V 5+ and Cr 6+ double doped nano lithium manganese oxide spinels Li[V x Cr x Mn 2-2X ]O 4 , (x=0.00, 0.02, 0.05 %)] were synthesized by doping the pure spinel LiMn 2 O 4 with vanadium and chromium ions as cathode materials for rechargeable batteries applications. These cathode materials were characterized by thermal gravimetric and differential thermal analysis (TG/DTA), x-ray powder diffractometry (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR) measurements. XRD and SEM studies confirmed the nano materials size for all prepared spinels. LiMn 2 O 4 and Li[V 0.05 Cr 0.05 Mn 1.9 ]O 4 spinels were irradiated by γ-irradiation (10 and 30 kGy). Direct-current (DC) electrical conductivity measurements indicated that these samples are semiconducting and their conductivity was strongly affected by the dopant cations and γ-irradiation. Keywords: lithium ion battery, vanadium and chromium co-doped spinels, γ-ray effect
A series of homobinuclear complexes of the type [M2L(NO3)n(H2O)m] where M=UO2(VI), ZrO(IV), Th(IV... more A series of homobinuclear complexes of the type [M2L(NO3)n(H2O)m] where M=UO2(VI), ZrO(IV), Th(IV); L=3-benzylidine-imino-5-p-sulphonamido phenyl azo-2-thiohyatoin(bispt), 3-furfurylidine-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(fispt),3-pyridyl-2’-methylene-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(pmispt) and 3-thienyl- 2’-methylene-imino-5-p-sulphoanamido phenyl azo-2-thiohydantoin(tmispt); n=8 for Th(IV) and 4 for others, m=4 for bispt and 3 for others have been synthesized and characterized on the basis of elemental analysis, thermal analysis, molar conductance, magnetic moment and spectroscopic data (IR, electronic and 1H-NMR). In the light of this information, the ligands can be visualized as tetradentate co-ordinating through azomethine nitrogen, carbonyl oxygen to one metal centre where as azo nitrogen and thioimido nitrogen to the other metal centre yielding homo binuclear complexes of the above composition. The fungi toxicity of the ligands & their zirconyl complexes against some fungal pathogen has been studied.
Various methods for improving the lower detection limit of polymeric membrane ion-selective elect... more Various methods for improving the lower detection limit of polymeric membrane ion-selective electrodes have been approached recently. The ion-selective electrode with solid-state membrane is described. Tetraphenyl borate as a lipophilic anion, is incorporated into the membrane of the electrode to improve its detection limit and selectivity. The detection limit was significantly lowered where nanomolar quantities were traced. Other favorable characteristics of the electrode are noticeably short response time of 5 seconds and good selectivity over the common interfering chemical species as well as its proven usefulness for determination of the surfactant in miscellaneous samples.
LiMn 2 O 4 is an attractive candidate cathode material for Li-ion rechargeable batteries, but it ... more LiMn 2 O 4 is an attractive candidate cathode material for Li-ion rechargeable batteries, but it suffers from severe capacity fading, especially at higher temperature (55 • C) during charging/discharging processes. Recently, many attempts have been made to synthesize modified LiMn 2 O 4. In this work, a new study on the synthesis of pure and U 4+-doped nano lithium manganese oxide [LiMn 2−x U x O 4 , (x = 0.00, 0.01, 0.03)] via solid-state method was introduced. The synthesized LiMn 1.97 U 0.03 O 4 was irradiated by γ-radiation (10 and 30 kGy). The green samples and the resulting spinel products were characterized using thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), infrared (IR), and scanning electron microscopy (SEM) measurements. XRD and SEM studies revealed nano-sized particles in all prepared samples. Direct-current (DC) electrical conductivity measurements indicated that these samples are semiconductors and the activation energies decrease with increasing rare-earth U 4+ content and γ-irradiation. ∆E a equals to 0.304 eV for LiMn 1.99 U 0.01 O 4 , ∆E a is 0.282 eV for LiMn 1.97 U 0.03 O 4 and decreases to ∆E a = 0.262 eV for γ-irradiated LiMn 1.97 U 0.03 O 4 nano spinel. The data obtained for the investigated samples increase their attractiveness in modern electronic technology.
Pristine lithium manganate (LiMn2O4) and Ag1+, Y3+ double doped nano lithium manganate [LiMn2−2xA... more Pristine lithium manganate (LiMn2O4) and Ag1+, Y3+ double doped nano lithium manganate [LiMn2−2xAgxYxO4, (x = 0.025, 0.05)] spinels were synthesized via a coprecipitation method for rechargeable batteries applications. The syn- thesized LiMn1.9Ag0.05Y0.05O4 was exposed to different doses of γ-irradiation (10 and 30 kGy). The resulting spinel products were characterized by using thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), electronic (UV-Vis) and electron spin resonance (ESR) spectra. LiMn2O4 exhibited a discharge capacity of 124 mAhg−1 while LiMn1.9Ag0.05Y0.05O4 had discharge capacities of 129 and 137 mAhg−1 for non irradiated and γ-irradiated (30 kGy) samples, respectively. The effects of the dopant cations and γ-irradiation on the discharge capacity and DC-electrical conductivity of some synthesized spinels were studied.
This paper introduces the development a new chemically modified carbon paste electrode (CMCPE) fo... more This paper introduces the development a new chemically modified carbon paste electrode (CMCPE) for the determination of a cationic surfactant. The paste is based on alkyl dimethyl hydroxyethyl ammonium chloride (ADHACl) with phosphomolybdic acid as an ion-exchan-ger (ADHA-PM). The electrode exhibits a Nernstian slope of 59.1 ± 0.5 mV/decade for ADHA ions in the concentration range 1.0 9 10-6 –1.0 9 10-3 M with the limit of detection of 8.2 9 10-7 M. The proposed electrode has a fast and stable response time of 5–8 s, a good reproduc-ibility and it can be used in the pH range of 2.2–9.0. Selectivity coefficients, determined by a matched potential method and separate solution method, showed high selec-tivity for ADHA over a large number of inorganic cations and organic cations. These characteristics of the electrode enable it to be used successfully for determination of ADHA in shampoo and liquid detergents solutions by standard addition and the calibration curve methods. In addition, the modified electrode was applied as an indicator electrode in potentiometric titration and successfully used to determine ADHA in water samples with satisfactory results. Keywords Alkyl dimethyl hydroxyethyl ammonium chloride Á Ion-selective electrode Á Potentiometry
A b s t r a c t Pure nano lithium manganese oxide spinel (LiMn 2 O 4) and Tb 3+ doped lithium man... more A b s t r a c t Pure nano lithium manganese oxide spinel (LiMn 2 O 4) and Tb 3+ doped lithium manganese oxide spinels [LiMn 2-xTbxO 4 , (x = 0.01%, 0.02%)] are synthesized via solid-state method. The synthesized LiMn 1.99 Tb 0.01 O 4 was irradiated by γ-irradiation with 30 kGy. The resulting spinel product is characterized by various methods such as thermo gravimetric and differential thermal analysis (TG/DTA), infrared (IR) spectroscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive of x-rays analysis (EDAX), electron spin resonances (ESR) studies and DC–electrical conductivity measurements. The XRD and SEM confirm the nano materials size for all prepared samples. DC–electrical conductivity measurements indicates that these samples are semiconductor and the activation energy decreases with increasing rare-earth Tb 3+ content; ΔE a = 0.427 eV for LiMn 1.99 Tb 0.01 O 4 , ΔE a = 0.339 eV for LiMn 1.98 Tb 0.02 O 4 and decreases to ΔE a = 0.330 eV for γ-irradiation of LiMn 1.99 Tb 0.01 O 4 nano spinel thus in role increases its attractiveness in modern electronic technology. Abou-Sekkina activation energy for the induced γ-irradiation is evaluated for the first time, which was found to be 0.097 eV.
A comparative study was made between two designs of benzalkonium ion (Bz)-selective electrodes: a... more A comparative study was made between two designs of benzalkonium ion (Bz)-selective electrodes: a silver-coated (solid contact) called electrode A and a PVC membrane (liquid inner contact) called electrode B based on benzalkonium-phosphomolybdate (Bz-PM) as ion-exchanger complex. Electrode A has a linear dynamic range from 2.0 Â 10 À 8 to 1.0 Â 10 À 2 mol L À 1 , with a Nernstian slope of 6070.3 mV/ decade and a detection limit of 2.0 Â 10 À 8 mol L À 1. Electrode B shows linearity over the concentration range from 2.0 Â 10 À 7 to 1.0 Â 10 À 2 mol L À 1 , with a Nernstian slope of 5571.2 mV/decade and a limit of detection of 1.5 Â 10 À 7 mol L À 1. Electrode A showed better performance than electrode B. The detection limit of benzalkonium chloride (BzCl) was effectively improved by a solid contact ion-selective electrode (SC-ISE), rather than the traditional liquid inner contact electrode that gives lower detection limits because of diminished ion fluxes. The present electrodes show clear discrimination of BzCl from several inorganic, organic ions, sugars and some common drug excipients. The sensors were applied efficiently for determination of BzCl in its pharmaceutical preparations (eye, ear and nasal drops) using standard addition and the calibration curve methods.
New mono-and binuclear copper(II) complexes with Schiff bases derived from the condensation of 2-... more New mono-and binuclear copper(II) complexes with Schiff bases derived from the condensation of 2-amino-5-substituted-aryl-1,3,4-thiadiazole with substituted aryl aldehydes were synthesized. The complexes were characterized by elemental analyses, molar conductivity, magnetic moment, IR, 1 H NMR, electronic, ESR and mass spectrometry as well as thermal analyses. The conductivity data of the complexes confirmed their non-electrolytic nature. An octahedral geometry was suggested for complex 1, square-planar geometry proposed for complex 2 and square pyramidal structure suggested for complexes 3-7. The 3D molecular modeling of a representative complex was carried out on a CS Chem 3-D Ultra Molecular Modeling and Analysis Program. The synthesized complexes and ligands were screened in-vitro for their antimicrobial activity against gram-positive bacteria (Staphylococcus aureus), gram-negative bacteria (Escherichia coli) and fungi (Aspergillus flavus and Candida albicans). In most cases, metallation increased the antimicrobial activity compared with the free ligands. Also, the catalytic effect of the prepared complexes on the cathodic reduction of oxygen was studied.
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