mohammad ali bodaghifard

In this study, a surface-modified solid support through the immobilization of sulfonic acid groups on magnetic nanoparticles (Fe3O4@SiO2@AE-SO3H). The structure of prepared hybrid nanostructure was characterized by various analyses. The catalytic activity of prepared hybrid nanomaterial was tested in the synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3-d]pyrimidinone derivatives. High to excellent yields, short reaction times, green solvent and conditions, easy workup procedure, reusability without a significant diminish in catalytic efficiency and simple separation of nanocatalyst by using an external magnet alongside the environmental compatibility and sustainability, are some benefits of this method. Furthermore, high acidic content of the prepared nanostructure makes it a good candidate for other acid-catalyzed organic transformation.

The remarkable stability of magnetic core and -OH functional groups on the surface of silica-coated magnetite (Fe3O4@SiO2) nanoparticles make them an excellent candidate for functionalization and catalytic applications. In this study, a surface-modified solid support was fabricated by immobilizing sulfonic acid groups on magnetic nanoparticles (Fe3O4@SiO2@AE-SO3H). The structure of prepared hybrid nanostructure was characterized by various analyses, including Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA/DTG), vibrating sample magnetometr (VSM), the field emission scanning electron microscopy (FE-SEM), and the electron-dispersive X-ray spectroscopy (EDS). The catalytic activity of prepared hybrid nanomaterial was assessed in the synthesis of 1-amidoalkyl-2-naphthols, resulting in high yields of the desired products under environmentally friendly conditions. High yields, short reaction times, green solvent and conditions, easy workup procedure, reusability without a significant diminish in catalytic efficiency and simple separation of nanocatalyst by using an external magnet alongside the environmental compatibility and sustainability are some advantages of this method.

In this research, the preparation of a reusable AlFeO3@SiO2@SO3H nanostructure as a perovskite-based magnetic nanomaterial is described. The structure of prepared AlFeO3@SiO2@SO3H was characterized by FT-IR, XRD, FE-SEM, EDS, TGA, and VSM analyses. The prepared acidic hybrid nanocatalyst showed high thermal stability and used as an efficient magnetic nanocatalyst in the synthesis of 3,4-dihydropyrimidin-2-one, and mono/ bis 1,4-dihydropyridine derivatives as pharmaceutically active heterocycles under solvent free conditions. High efficiency of procedure, good yields, short reaction times, magnetic recovery and reusability of nanocatalyst, high thermal stability of catalyst, and environmentally benign conditions are highlights of this new protocol.

Excessive increase in industrial activities in recent years has led to the uncontrolled entry of industrial effluents containing large amounts of heavy metals into the environment and can have irreversible effects on human, animal and plant health. In this project, the preparation of magnetic hybrid nanomaterial (Fe3O4@SiO2-PMT) was presented by a simple method and used as an adsorbent to remove Cu2+ and Ni2+ ions. The maximum removal efficiency was 91% for copper and 96% for nickel. The highest removal efficiencies for copper and nickel were obtained at pH=7, a concentration of 0.05 g of adsorbent and a duration of 90 minutes. The desorption results showed that about 90% of the nanomaterials were recycled and significant reduction in nanoparticle adsorption capacity was not observed. The leaching test also showed good stability of the prepared adsorbent under acidic conditions, because a small amount of iron had entered the solvent after 72 hours. Advantages of this method include high removal ability, low cost, reusability of the adsorbent, and the easy separation of the adsorbent.

Due to the persistence of polycyclic aromatic hydrocarbons (PAHs) in soil and sediments, and their toxic, mutagenic, and carcinogenic effects, the remediation of PAH-contaminated sites is an important role for environment pollution. In this study, the chemical oxidative remediation of anthracene-contaminated soils was investigated by magnetite nanoparticles (Fe3O4) catalyzed Fenton-like oxidation in the presence of hydrogen peroxide 30% (H2O2) and urea-hydrogen peroxide (UHP) at neutral pH. Urea-hydrogen peroxide (UHP), as a safer oxidizing agent, is used for the first time in the Fenton process. The magnetite nanoparticles improved the production of hydroxyl radicals, and the removal of polycyclic aromatic hydrocarbons (anthracene as a model compound) from the soil samples. The structure of Fe3O4 nanoparticles was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The removal efficiency of anthracene at an initial concentration 2500 (mg kg-1) was 95% for 2.5 mmol by using hydrogen peroxide and 93% for 0.1 mmol of UHP at the optimum oxidation condition. The anthracene reaction was analyzed by ultraviolet-visible spectroscopy (UV-Vis). The UHP safety and efficiency, neutral pH condition, the limited iron leaching and its easy magnetic separation makes magnetite nanoparticles-UHP a promising catalytic system in remediation of polycyclic aromatic hydrocarbons in contaminated soils.

In this research study, relative stability of all the tautomers of phthalazinone ring in the gas phase and the solvent effect on the tautomeric equilibrium were evaluated using the density functional theory-polarizable continuum model at the B3LYP/6-311++G(d,p) basis set. In addition, variation of the dipole moments in the gas phase and solution, the specific solvent effect on the transition state of proton transfer assisted by a water molecule and the NBO calculated charges on the atoms were investigated. The water-assisted tautomerization with one molecule revealed that, the free energy activation barrier was reduced compared to those for the uncatalyzed systems. In the all the tautomers of phthalazinone rings, when going from gas phase to more polar solvents, the net charges on the O atoms slightly increased.

In this study, magnetite nanoparticles (Fe3O4) were synthesized as a magnetic core by chemical co-precipitation process and coated with a silica layer. The (Fe3O4@SiO2) core-shell magnetic nanoparticles were functionalized by organic-base tags to produce the MNPs-TBAN nanoparticles as a novel hybrid nanostructure. The morphology, stability, and magnetism of this hybrid nanostructure were characterized and studied by Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), vibrating sample magnetometry (VSM), X-ray powder diffraction analysis (XRD), scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The prepared hybrid nanomaterial was successfully used as a basic heterogeneous catalyst for the synthesis of pyrano[2,3-d]pyrimidine derivatives, via the condensation of an aldehyde, malononitrile and barbituric acid or thiobarbituric acid. The reaction was afforded the desired products in high purity and has advantages of excellent yields, simple workup procedure, and short reaction time. The catalyst was easily separated from the reaction mixture with the assistance of an external magnet and reused for several runs without noticeable deterioration in catalytic activity.

In this study, Fe3O4@SiO2-PAF-SO3H nanocomposite was successfully fabricated by immobilization of sulfonic acid groups on the surface of poly(anilin-formaldehyde)-supported on magnetic Fe3O4@SiO2 nanoparticles through layer-by-layer assembly. Fe3O4@SiO2-PAF-SO3H composite nanostructure has been fully characterized using various techniques including the Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction patterns (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and vibrating sample magnetometry (VSM). The one-pot synthesis of mono and bis 1,4-dihydropyridine derivatives, as pharmaceutically interesting compounds, have been achieved in high yields via three-component and pseudo five component condensation of an aromatic aldehyde, ammonium acetate and ethyl acetoacetate in the presence of Fe3O4@SiO2-PAF-SO3H as a novel retrievable hybrid nanocatalyst under solvent-free conditions. This protocol has advantages in terms of short reaction time, solvent-free condition, high yield and purity, easy work-up and eco-friendly process as well as recyclability of the nanocatalyst (at least 6 times) with no decrease in catalytic activity.

Synthesis of bis sulfamic acid-grafted on silica-coated nano-Fe3O4 particles (MNPs-TBSA) as a novel core/shell hybrid organic-inorganic magnetic nanostructures, and their performance as a retrievable heterogeneous acidic catalyst is disclosed. The catalytic performance of this novel material was studied for the green synthesis of pharmaceutically valuable polyhydroquinoline and tetrahydrobenzopyran derivatives via one-pot multi-component condensation of aryl aldehydes, dimedone, ethyl acetoacetate, malononitrile and ammonium actate in ethanol as a solvent and at 70 º C. Eco-friendly method, high yield and purity of the desired products, short reaction time along with the ease of the workup procedure outlines the advantages of these new methodologies over the earlier ones. Surface and magnetic properties of the core/shell hybrid nanoparticles were characterized via field emission scanning electron microscopy (FE-SEM), X-ray diffraction measurements (XRD), the energy dispersive X-ray spectroscopy (EDS), FT-IR spectroscopy and vibrating sample magnetometer (VSM). The crystallite size of the magnetic nanoparticle is calculated to be 15.5 nm.

Mild and applicable synthesis of mono-, bis-, and spiro- perimidines is demonstrated in high yields via the condensation of 1,8-diaminonaphthalene and aldehydes or ketones in the presence of sulfamic acid as a green and highly efficient catalyst. This environmentally benign and clean synthetic pathway offers several advantages, such as high yields, short reaction times and easy work-up procedure.