JOURNAL OF APPLIED CHEMISTRY
Year:2018 | Volume:13 | Issue:47|Papers Count:12

In this research work new heteroleptic Ni(II) and Pt(II) complexes have been synthesized by using 5-bromo-2-hydroxybenzaldehyde-4-phenylthiosemicarbazone as main ligand and triphenylphosphine and imidazole as auxiliary ligands. The ligand and complexes have been characterized by elemental analysis and spectroscopy. On the basis of results thiosemicarbazone is coordinated to metal ion as a dianionic tridentate ONS ligand and the coordination sphere is completed by the auxiliary ligand. Antibacterial activity of ligand and complexes was evaluated against B. subtilis and S. aureus and P. aeruginosa All complexes exhibit more inhibitory effect than the parent ligand and complexes containing imidazole have more activity than others.

In this study, magnetic Fe3O4 nanoparticles were synthesized by co-precipitation method and then Au shell was extended over these nanoparticles via chemical reduction of chloroauric acid with sodiumborohydride under ultrasound irradiation. The obtained Au/Fe3O4 nanoparticles were characterized by using X-ray diffraction technique and Fourier transform infrared spectroscopy and their physical properties was studied by scanning electron microscopy and transmission electron microscopy. The characterized nanoparticles were used as efficient catalyst in the degradation of Rhodamine 6G dye in aqueous solution. UV-Vis spectroscopy was used to determine the dye concentration during optimization of the reaction conditions, and effect of various parameters such as pH, catalyst loading, temperature, and amount of the oxidant was investigated. It was found that Au/Fe3O4 catalyst at 80 oC in the pH of 12 can effectively degrade Rhodamine 6G dye molecules in the presence of hydrogen peroxide as an inexpensive and available oxidant. The catalyst after recycling was also, able to perform its role in successive runs.

Co3O4/MWCNT/TiO2NTs/Ti electrodes were prepared by Electrdeposition of Multe-Walled Carbon Nano Tubes-Co3O4 nanocomposite onto previously formed TiO2 nanotubes. Microstructure studies show that Co3O4/MWCNT having high surface area has been deposited onto the TiO2NTs arrays. The capacitive behavior of the new electrode was investigated by cyclic voltammetry (CV), charge– discharge test and electrochemical impedance analysis (EIS). The electrochemical data demonstrated that the electrodes displayed high specific capacitance compared to Co3O4/TiO2NTs/Ti. The EIS studies showed that MWCNTs in the nanocomposite can significantly improve the parameters effectively influencing the capacitive behavior such as ohmic resistance (Rs), charge transfer resistance (Rct) and faradaic pseudocapacitance element (CPE).

The inhibition ability of N-methyl thiourea against the corrosion of steel X52 in 1 M HCl solution was evaluated by potentiodynamic polarization and scanning electron microscopy. Polarization studies indicated that N-methyl thiourea retards both the cathodic and anodic reactions through adsorption and blocking the active corrosion sites. The adsorption of N-methyl thiourea indicated the Langmuir adsorption isotherm. Thermodynamic and kinetic parameters such as enthalpy, activation energy and entropy were calculated. Gibbs free energy showed that the adsorption process is spontaneous. Scanning electron microscopy was used to study the steel surface. Surface studies show that the surface of sample in the presence of N-methyl thiourea looks more uniform with lower roughness than that in the uninhibited solution.

A new mild and efficient procedure for the ring opening of epoxides by acetate anion in the presence of catalytic amounts of silica-bound polyethylene glycol substituted 1-methylimidazolium bromide, SiO2-PEG-ImBr, as an effective heterogeneous phase transfer catalyst in aqueous media is developed. A variety of β-acetoxy alcohols are obtained in high yields with excellent regioselectivity in short reaction times. The remarkable features of this procedure are improved yields, high regioselectivity, small quantity of catalyst, easy work-up, ease of recyclability of catalyst and environmentally friendliness. The recycled catalyst could be reused over four times with almost no loss of catalytic activity. A new mild and efficient procedure for the ring opening of epoxides by acetate anion in the presence of catalytic amounts of silica-bound polyethylene glycol substituted 1-methylimidazolium bromide, SiO2-PEG-ImBr, as an effective heterogeneous phase transfer catalyst in aqueous media is developed. A variety of β-acetoxy alcohols are obtained in high yields with excellent regioselectivity in short reaction times. The remarkable features of this procedure are improved yields, high regioselectivity, small quantity of catalyst, easy work-up, ease of recyclability of catalyst and environmentally friendliness. The recycled catalyst could be reused over four times with almost no loss of catalytic activity.

Three samples of polyvinylpyrrolidone (PVP) composites were prepared by solution casting with the leaf powder (LP), leaf carbon (LC) and leaf ash (LA) of Buxus sempervirens L. The bio-resource ingredients of the composites were obtained from the leaves of the plant on milling and heating at 250 ° C or 700 ° C, respectively. The resulting bio-composites were characterized by diffuse reflectance spectroscopy (DRS) and IR spectroscopy as well as by XRD analysis. Investigation of the thermal properties of these composites by TGA and DTA measurements has revealed some improvements in thermal properties of polyvinylpyrrolidone after composition with the powder, ash, and carbon of the leaf. Additional experiments exhibited considerable differences between hydrophilicity of the composites and PVP. ُSimple hydrophilicity tests showed that the prepared composites are less hydrophilic than pure PVP.

In this research we report synthesis Iron-Barium mixed oxide nanoparticles, (BaFe2O4) using Fe(phen)3]2[Ba(SCN)6(H2O)2 Ø Œ and via thermal decomposition of inorganic precursor complex method. The complex characterized then was placed in the furnace at 900° C for 4h to preparation of nano-porous oxide particle as BaFe2O4 of them based on studies. The properties and particle size of prepared nanoparticles were characterized using powder X-ray diffraction (XRD), furrier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and vibrating sample magnemeter (VSM). Images of SEM show that the form of nanoparticle and almost the morphology and uniformity in the image of them, relatively spherical and porous and beneath the high porosity for use as a catalyst for much is suitable. XRD data show that the nano system related to BaFe2O4 and confirms the fact pure crystalline phase was obtained and another phase is not formed in the system. The reason is the purity of the precursor complex. The average size of the particles is 5. 417nm. The average crystallite size using Scherrer equation is 5. 417 nm. VSM show that nanoparticles have soft ferromagnetic properties.

In this study, a simple but sensitive sensor, Carbon paste electrode (CPE) was used for the determination of curcumin in human blood serum with high selectivity. The electrochemical behavior of curcumin at CPE was studied by cyclic voltammetry (CV). Furthermore, dependence of the oxidation and reduction currents of curcumin on pH of the experimental solution and the potential scan rate were also investigated. Using differential pulse voltammetry (DPV), the calibration plot was obtained within the concentration range of 3-300 µ M with the detection limit of 5. 03 µ M. Electrochemical detection of curcumin by CPE electrode was achieved in this study with different technique.

Zirconium Salen encapsulated into Dealuminated Y Zeolite (ZrSalen-DAZY) was prepared through flexible ligand method. This heterogeneous catalyst was characterized by XRD, FT-IR, DRS, EDX and FESEM technique. The amount of ZrSalen in the nanocage of zeolite was 0. 082g/g of zeolite. This Catalytic system was used for efficient oximation of aldehydes under magnetic stirring conditions at room temperature and the corresponding products were obtained in 60-95% yields. Catalyst amount for this reaction was 0. 6g zeolite (equal 0. 0492 g ~0. 14 mmol) Zrsalen into DAZY. This catalytic system also shows good shape selectivity towards linear aldehydes. This hetersgenous catalyst reused several times without loss of its catalytic activity.

A practical and mild synthetic strategy has been investigated for the ligand free arylation of aromatic amines and nitrogen heterocycles using nano-Fe3O4@Cellulose-NH2-CuI as a recoverable catalyst based on magnetic cellulose. ّ Firstly, the cellulose was functionalized with amine groups and then was composite with nano-magnetic particles and Copper(I) iodide. The development of efficient methodology for formation C-N bond is one of the most important reactions in organic chemistry. The nano-Fe3O4@Cellulose-NH2-CuI as a cheap, heterogeneous and recyclable catalyst produced the corresponding compounds in high yields. The recyclability, high yields, short reaction times and simple procedure of reaction are merits of this new methodology.

This study reports on the preparation and characterization of porous clay heterostructure (PCH) as a high-surface area support for CuO nanoparticles based antibacterial activity for Gram-positive and Gram-negative bacteria. CuO nanoparticles were incorporated in PCH by thermal decomposition method and characterized by diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption-desorption measurements (BET) and transmission electron microscopy (TEM), The TEM results showed that nanoparticles are nearly spherical and particles size in the range of less than 10 nm. The powder X-ray diffraction indicated that PCH contained both MMT clay and MCM-41 and have located in the clay interlayers speaces. The diffuse reflectance spectra demonstrated the presence of CuO, Cu2O and Cu nanoparticles in PCH. The nanocomposite (CuO-PCH) was used for antibacterial testing. The antibacterial activity of CuO-PCH nanocomposite was tested against Gram-positive and Gram-negative bacteria. The nanocomposite showed efficient bacterial effect against Gram-positive bacteria. The mechanism of antibacterial activity of CuO-PCH nanocomposite was discussed.

Synthesis, characterization and application of mesoporous silica materials MCM-41 and MCM-48 modified by Zirconium (IV) were investigated. The synthesized materials were characterized by means of Fourier transform infrared (FT-IR), Thermogravimetric analysis (TGA), N2 adsorption /desorption measurements analysis and X-ray diffraction (XRD) analysis. Synthesized materials were used as efficient heterogeneous catalysts for the Knoevenagle condensation reaction in water with good to excellent yields. In fact, modification of MCM-41 and MCM-48 mesoporous materials with bonded aminosilane species, Schiff base preparation by isatin and finally complexation with zirconium, has attracted much attention in order to design catalyst with advanced applications in the kneovenagel condensation reaction. Obtained results by these heterogeneous catalysts revealed several advantages including short reaction times, simple workup, easy isolation and reusability.