Showing papers by "Roya Ahmadi published in 2017"

Chemoselective Reduction of Nitro and Nitrile Compounds with Magnetic Carbon Nanotubes-Supported Pt(II) Catalyst under Mild Conditions

Abstract: Multi-walled carbon nanotubes (MWNTs) decorated with Fe3O4 nanoparticles have been prepared using a coprecipitation technique and were surface modified using poly(citric acid) (PC) dendrimer. These PC-functionalized magnetic carbon nanotubes (MWCNT/MA@PC) have been used as a novel support for Pt(II) complex immobilized as magnetic nanocatalyst (MWCNT/MA@PC/Pt(II)). The morphology and structural features of the magnetic nanocatalyst were characterized using different microscopic and spectroscopic techniques, including FT-IR, TEM, EDX, BET, XRD, TGA, ICP, and VSM. The nitro and nitrile groups in aromatic and aliphatic compounds containing various reducible substituents, such as carboxylic acid, ketone, aldehyde, and halogen, are selectively reduced to the corresponding amines in water as a eco-friendly solvent with excellent yields by employing NaBH4 in the presence of MWCNT/MA@PC/Pt(II). In addition, the Pt(II) magnetic nanocatalyst can be simply separated from the mixture of reactants by using an external...

Synthesis, spectroscopic characterization, crystal structure and thermal analyses of two zinc(II) complexes with methanolysis of 2-pyridinecarbonitrile as a chelating ligand

Abstract: Zinc(II) complexes, [Zn(MPCA)3][ZnCl4] (1) and [Zn(MPCA)3][ZnBr4] (2) (where MPCA is O-methylpyridine-2-carboximidate), were synthesized from the reaction of ZnCl2 and ZnBr2 with 2-pyridinecarbonitrile in methanol, respectively. Both complexes were thoroughly characterized by elemental analysis, thermogravimetric analysis, differential thermal analysis and IR, UV–Vis, 1H NMR spectroscopy, and their structures have been determined by the single-crystal X-ray diffraction. The spectroscopic investigations and X-ray structural analysis indicated that in both complexes, the nitrile group of ligand has been methoximation in methanol solvent in the presence of zinc(II) salts. The luminescence spectra of both complexes show that the intensity of their emission bands is stronger than that of the bands for the free O-methylpyridine-2-carboximidate ligands.

Study of thermodynamic parameters of (TATB) and its fullerene derivatives with different number of Carbon (C20, C24, C60), in different conditions of temperature, using density functional theory

Abstract: In this research 1, 3, 5-triamino-2, 4, 6-trinitrobenzene (TATB) were attached with different nano structures of fullerene with 20, 24 and 60 carbons producing nano structures with diverse molecular weights. Then by the use of density functional theory methods, thermodynamic parameters of TATB with foregoing nanostructures, in wide of temperature, between 300-400 oK were computed. To this purpose, the materials on both sides of suggested synthesis reactions were geometrically optimized, and then, the calculations of the thermodynamic parameters were performed on all of them. The values of enthalpy, Gibbs free energy and Specific heat capacity for these reactions were obtained. Also important parameters such as energy levels, the amount of HOMO/LUMO values and related parameters including electrophilicity scale, chemical hardness, chemical potential, and the maximum amount of electronic charge transferred were derived. Finally, the effect of type and molecular weight of nano structure fullerene (C20, C24, C60) on explosion properties and other chemical properties of TATB were evaluated.

Investigating the Complexation of a Recently Synthesized Phenothiazine with Different Metals by Density Functional Theory

Abstract: In this research, the complexation of a new recently synthesized phenothiazine with 10 different metals was evaluated by Density functional theory. At the first step, the structures of 6,15-diazabenzo[a][1,4]benzothiazino[3,2-c]phenothiazine, cations and their complexes with the mentioned material were optimized geometrically. Then, IR calculations were performed on them to obtain the values of formation enthalpy and Gibbs free energy. The acquired results indicate that Cu2+ forms the most stable and strongest complex with 6,15-diazabenzo[a][1,4]benzothiazino[3,2- c]phenothiazine. Hence, this substance can be utilized as an outstanding ionophore or a potential ligand in the determination of copper by ion selective electrodes and different extraction methods respectively. All calculations were applied by Density functional theory in the level of B3LYP / 6-31G(d).

Clinical and histomorphometric assessment of lateral alveolar ridge augmentation using a corticocancellous freeze-dried allograft bone block

Abstract: Horizontal ridge augmentation with allografts has attracted notable attention because of its proper success rate and the lack of disadvantages of autografts. Corticocancellous block allografts have...

Calculation of Thermodynamic Parameters of [2.4.6] Three Nitro Toluene (TNT) with Nanostructures of Fullerene and Boron Nitride Nano-cages over Different Temperatures, Using Density Functional Theory

Abstract: In this study explosive substance [2.4.6] three Nitro Toluene (TNT) was attached with nanostructures of fullerene (C24) and boron nitride nano-cages (B12N12). After that using B3LYP (Becke, three-parameter, Lee-Yang-Parr), a method from density functional theory (DFT), thermodynamic parameters of TNT with foregoing nanostructures, in different conditions of temperature, were computed. To this aim, the materials on both sides of suggested synthesis reactions were geometrically optimized, and then, the calculations of the thermodynamic parameters were done on all of them. The values of enthalpy(ΔH), Gibbs free energy(ΔG) and Specific heat capacity(Cv) for these reactions were computed, also various parameters such as energy levels, the amount of HOMO/LUMO values and related parameters including electrophilicity scale, chemical hardness, chemical potential, and the maximum amount of electronic charge transferred were computed, Finally, the effect of type and Molecular weight of nano structure fullerene ( C24, B12N12) on explosion properties and other chemical properties of TNT were evaluated.