62 research outputs found
STRUCTURAL OF SUPRAMOLECULAR HYDROGEN BONDING DIOXOURANIUM (VI) COMPLEXES
The azodye ligands were synthesized from the coupling of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one with aniline derivatives and characterized by elemental analyses, IR and NMR spectroscopy. Dioxouranium (VI) complexes of the prepared ligands were characterized by elemental analyses, conductance, thermal analysis and spectral (UV, IR and NMR) results. IR spectra show that the ligands behave as a monobasic bidentate coordinating via the hydrazo nitrogen atom and CO of the pyrazole ring. Thermal studies to verify the status of water molecules inside or outside the coordination sphere of the central metal ion. The optimized bond lengths, bond angles and the calculated quantum chemical parameters for the ligands were investigated. The coordination geometries and electronic structures are determined from a framework for the modeling of the complexes. The force constants, FUO (10-8 N/Ao) and the bond lengths, RUO (Ao) have been calculated from an asymmetric stretching frequency of O-U-Ogroup
Synthesis and Properties of Complexes of Copper(II), Nickel(II), Cobalt(II) and Uranyl Ions with 3-(p-Tolylsulphonamido)rhodanine
Metal complexes of copper(II), nickel(II), cobalt(II), uranyl(II) with 3-(p-tolylsulphonamido)rhodanine (HL) have been prepared and characterized by chemical and thermal analyses, molar conductivity, magnetic susceptibility measurements, and infrared, electronic and EPR spectra. The visible and EPR spectra indicated that the Cu(II) complex has a tetragonal geometry. From EPR spectrum of the Cu(II) complex, various parameters were calculated. The crystal field parameters of Ni(II) complex were calculated and were found to agree fairly well with the values reported for known square pyramidal complexes. The infrared spectral studies showed a monobasic bidentate behaviour with the oxygen and nitrogen donor system. Thermal stabilities of the complexes are also reported
Synthesis, characterization and microstructural evaluation of ZnO nanoparticles by William-Hall and size-strain plot methods
ABSTRACT. At various calcination temperatures 450, 550 and 650 °C, zinc oxide nanoparticles were produced. Calcinated ZnO has high surface area as the BET was 119.12 m2gâ1 and the average particle radius was calculated to be 1.16 nm. The dimension of crystallites and straining in ZnO nanoparticles' diffraction peaks remained measured. The WilliamsonâHall (WâH) technique besides the sizeâstrain approach stayed used. For each of XRD reflection peaks, physical characteristics like strain and stress were computed. Towards regulate the magnitude of crystallites, the WilliamsonâHall (WâH) approach besides the sizeâstrain technique are used that is good agreement with the size that determine from SEM as it was 22.6, 26.6 and 32.6 nm for ZnO calcinated at 450, 550 and 650 oC, individually. Using the WâH plot to modify the subversion shape, assuming an unvarying distortion model (UDM), unvarying stress deformation model (USDM), unvarying deformation energy density model (UDEDM), and The sizeâstrain plan (SSP) approach was used to determine this. The SEM and Scherrer methods match well with the crystal size of ZnO NPs determined using WâH plots and the SSP technique.
KEY WORDS: Zinc oxide nanosphere, Calcination, Physical characterization, WâH investigation, SSP technique
Bull. Chem. Soc. Ethiop. 2022, 36(4), 815-829.
DOI: https://dx.doi.org/10.4314/bcse.v36i4.8  
Efficient adsorption of Rhodamine B using a composite of Fe3O4@zif-8: Synthesis, characterization, modeling analysis, statistical physics and mechanism of interaction
ABSTRACT. The utilization of a metal organic framework (ZIF-8) modified by Fe3O4 nanoparticles was used to accomplish adsorption of Rhodamine B (RB) from aqueous solutions. SEM, XRD, IR, and BET analyses were all used to characterize the composite (Fe3O4@ZIF-8). The surface area of this adsorbent was 478.4 m2/g. X-Ray diffraction spectroscopy was used to detect surface modification utilizing electron microscopy (SEM) scanning with 48 nm in diameter average particle size according to a statistical physics method. Fe3O4@ZIF-8 appears to have dispersive interactions and pore characteristics, according to quantum chemistry simulations. On the adsorption of RB, the influences of contact time, adsorbent quantity, dye concentration, and temperature were studied. The Langmuir and Freundlich adsorption isotherm models were used to study the adsorption isotherms. Anticipated overall adsorption potential was 647.5 mg/g, with a zero-charge point (pHPZC) of 4.3. The adsorption isotherm was fitted using Langmuir whereas pseudo second order was used to match the kinetics. Energy of adsorption (Ea) is 28.7 kJ/mol, indicating a chemisorption phase. The adsorption process is endothermic and unpredictable, according to thermodynamic experiments. It was also looked into using ethanol as a solvent in the desorption of deposited cationic dye.
KEY WORDS: Fe3O4@ZIF-8, Rhodamine B, Adsorption models, Thermodynamics
Bull. Chem. Soc. Ethiop. 2023, 37(1), 211-229.
DOI: https://dx.doi.org/10.4314/bcse.v37i1.17  
Measurement and correlation of the solubility of telmisartan (form A) in nine different solvents from 277.85 to 338.35 K
The solubility of telmisartan (form A) in nine organic solvents (chloroform, dichloromethane, ethanol, toluene, benzene, 2-propanol, ethyl acetate, methanol and acetone) was determined by a laser monitoring technique at temperatures from 277.85 to 338.35 K. The solubility of telmisartan (form A) in all of the nine solvents increased with temperature as did the rates at which the solubility increased except in chloroform and dichloromethane. The mole fraction solubility in chloroform is higher than that in dichloromethane, which are both one order of magnitude higher than those in the other seven solvents at the experimental temperatures. The solubility data were correlated with the modified Apelblat equation and λh equations. The results show that the λh equation is in better agreement with the experimental data than the Apelblat equation. The relative root mean square deviations (Ï) of the λh equation are in the range from 0.004 to 0.45 %. The dissolution enthalpies, entropies and Gibbs energies of telmisartan in these solvents were estimated by the Vanât Hoff equation and the Gibbs equation. The melting point and the fusion enthalpy of telmisartan were determined by differential scanning calorimetry
Thermodynamics of substituted coumarin VII: Potentiometric and spectrophotometric studies of 1-acetyl-2-(coumarin-iminecarboxamide-3-yl) hydrazine transition metal complexes
Al-Sarawy, âStereochemistry of new nitrogen containing heterocyclic aldehyde. IX. Spectroscopic studies on novel mixed-ligand complexes of 6 The Scientific World
The synthesis of several new coordination compounds of copper(II), nickel(II), cobalt(II), manganese(II), iron(II), tin(II), mercury(II), dioxouranium(VI) and iron(III) with Schiff bases derived from 7-formyl-8-hydroxyquinoline(oxine) and 2-aminophenol (H 2 L 1 ) or 2-aminopyridine (HL 2 ) are described. The ligands and the complexes have been characterized by elemental analyses, IR, UV, EPR, 1 H-NMR and 13 C-NMR spectra, together with magnetic susceptibility measurements. The [CuL 1 ] 2 Ă2H 2 O complex shows a subnormal magnetic moment, due to antiferromagnetic exchange interaction, while the other complexes show a normal magnetic moment. IR and NMR studies show that the Schiff bases behave as mono-dibasic and tridentate ligands, coordinating through the oxygen atom of the deprotonated phenolic group, the nitrogen atom of the azomethine group and pyridine. Key words: quinoline Schiff bases, solid complexes, EPR, synthesis Chemical properties of quinoline and its derivatives are of interest due to their biological activity [1], coordination capacity EXPERIMENTAL Preparation of the ligands and their metal complexes: 7-Formyl-8-hydroxyquinoline(oxine) was prepared according t
Synthesis, structural characterization, antioxidant, cytotoxic activities and docking studies of schiff base Cu(II) complexes
By combining hydrazide with 2-Acetylpyridine, a hydrazone ligand (HL) was successfully created. Several copper (II) salts have been used to create three copper (II) hydrazone complexes (acetate, sulphate, and chloride). The hydrazide ligand and its copper (II) complexes (1â3) were studied via variety of analytical techniques, including elemental analysis, electronic, infrared, UVâvis Spectrum, XRD study, thermal analysis, also molar conductivity amounts. The spectrum results indicate that in all complexes, the ligand exhibits monobasic tridentate behavior. Octahedral geometries were present in all metal complexes. The Coats-Redfern equations were used to compute and describe the dynamics properties of several steps of TGA (Ea, A, ÎH*, ÎS*, and ÎG*). Calculations using the density functional theory (DFT) were done at the molecular studio software toward examine ligands agent's and its complexes' best structures. The MCF-7 in addition to HepG-2Â cell lines was resistant to tumor-inducing effects of the copper (II) chelates. The in vitro antioxidant capacities of all complexes have been estimated via DPPH free radical scavenger assays. Furthermore, zones of inhibition length accustomed to test antimicrobial effect of particular complexes in vitro towards Staphylococcus aureus (Gram positive bacteria) E. coli (Gram negative bacteria). Both absorption spectra and viscosity measurements in calf thymus DNA binding have been used to study the complexes. In order to explore docking research of copper (II) chelates, the crystallographic construction of the SARS-active CoV-2's site protein (PDB ID:6XBH) was used (COVID-19) and breast cancer distorted (PDB ID: 3hb5)
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