Journal of Chemical Reactivity and Synthesis
Volume:12 Issue: 3, Summer 2022

A convenient and efficient procedure for synthesis of Bis(4-HydroxyCoumarin) derivatives has been developed by a simple one-pot, one step ultrasonic-assisted reaction to produce Bis(4-HydroxyCoumarins) in room temperature. The present methodology offers several advantages, such as a simple procedure with an easy work-up, short reaction times, high yields, and the absence of any volatile and hazardous organic solvents.

In this study, the effect of integer Hall effect on nanoribbons of boron nitride at the presence of impurity function concerning magnetic resistance in terms of filling ratio was investigated. First, a dopant will be applied to the system in the form of Dirac Delta function, at the presence of this dopant, Landau levels will be divided into extended and localized levels giving rise to Hall step. In this model, the Aharanov-Boehm fluctuations are observed and impurity eradicates stagnation in energy levels. In fact, by increasing the width and height of the quantum dot destroys the step, and finally, the quantum-hall effect vanishes Then, another dopant will be applied to the system in the form of quantum dot. By increase of the width and height of quantum dot, the Hall step will fade and quantum Hall effect will disappear. The more the increase of quantum hall domain, the faster the Hall step and therefore quantum effect will fade.

Zinc sulphide (ZnS) nanoparticles were synthesized by simple aqueous chemical reaction of zinc chloride and sodium sulphide in an aqueous solution. The main advantage of ZnS nanoparticles of diameter 29 nm was that the sample could be prepared by using of cheap precursors in a cost effective and eco-friendly manner.  Structural, morphological and chemical composition of the prepared  nanoparticles were investigated by X-Ray Diffraction(XRD),Scanning Electron Microscopy(SEM) with energy dispersion X-ray dispersive fluorescence spectroscopy (EDAX) and Fourier transform infrared (FTIR) spectroscopy. The antimicrobial effects of the zinc sulphide (ZnS) nanocrystals   and the anticarcinogenic agent imatinib were studied by spot inoculation technique and also by well diffusion technique against twelve pathogenic bacterial strains.  Nanoparticles of ZnS showed antimicrobial activity against both Gram positive and Gram negative strains except Shigella sonnei. The anticancer drug imatinib was inhibitory for only Gram positive organisms, Bacillus subtilis and Staphyloccus aureus. Synergism between imatinib and ZnS nanoparticles was distinctly observed in all the Gram positive strains.

The applicability of Albizia Lebbeck Leaves-capped silver nanoparticles (ALL-AgNPs) synthesis to dyes removal from aqueous solutions has been reported. The main goal of this work was development of a practical system to acquire the optimal conditions of removal accompanied by ultrasonic for maximizeing removal of Auramine O (AO) and Crystal Violet (CV) onto ALL-AgNPs in aqueous solution based on RSM (response surface methodology). To characterization of this novel materials techniques of X-ray diffraction (XRD), Fourier transform infrared  (FT-IR) and scanning electron microscopy (SEM) were employed. The influences of several parameters including initial AO concentration (X1), initial CV concentration (X2), pH (X3), adsorbent dosage (X4), sonication time (X5) evaluated based on CCD (central composite design) using RSM. The process was empirically modeled to reveal the significant variables and their possible interactions. The optimal prameters of ultrasound time, pH, adsorbent mass, AO and CV concentration were obtained 5 min, 6.0, 0.025 g, 25 mg L-1, respectively. The application of isotherms in obtaining the thermodynamic parameters like enthalpy (ΔH0), free energy (ΔG0) and entropy (ΔS0) for adsorption process were confirmed. The maximum monolayer capacities (Q max) of AO and CV were obtained 73.2 and 48.7 mg/g, respectively under optimal conditions.

In this study, using the density functional theory (DFT) computational methods and Monte Carlo simulation, the interaction of methotrexate (MTX) and its derivative (L-FMTX) with Single-walled carbon nanotubes (SWCNTS) was investigated. Through the DFT method, the effects of different solvents (water, methanol, ethanol, dimethyl sulfoxide and dimethylformamide) on the interaction of methotrexate (MTX) and its derivative (L-FMTX) with Single-walled carbon nanotubes within the Onsager self-consistent reaction field (SCRF) model, as well as the effects of temperature on the stability of interactions between compounds in various solvents were studied. Using theoretical calculations, The effects of temperature on the stability of the bond between the compounds and total density of states (DOS) as well as boundary molecular orbitals (FMOS) related to the mentioned compounds were investigated. The molecular properties of compounds such as ionization potential (I), electron affinity (A), chemical hardness (η), electronic chemical potential (µ) and electronegativity (χ) were also used. The interaction resulting from the binding of methotrexate (MTX) to Single-walled carbon nanotubes as well as the interaction of the methotrexate derivative (L-FMTX) with Single-walled carbon nanotubes were studied through molecular mechanics using the Monte Carlo simulation method in the four AMBER, OPLS, CHARMM and MM+ force fields at different temperatures. The results showed that the MTX structure with the SWCNT single wall nanotube was more stable than the L-FMTX structure with SWCNT single wall nanotube. The results showed that the most stable solvent for the above-mentioned structures was water and that the most efficient force field was MM+.

In this study, we survey electronic and magnetic configuration of (LaMnO3)1/(SrTiO3)4, (LaMnO3)2/(SrTiO3)4, (LaMnO3)3/(SrTiO3)4 superlattices based on density functional calculations (DFT+U) using Quantum-Espresso open source code. The Hubbard parameter has been calculated for the Mn and Ti atoms using a linear response approach. This parameter is 3.5 eV for LaMnO3 and it is 4.98 eV for SrTiO3, are in good agreement with the experimental results. The results of total and partial density of states calculations of the LaMnO3 and SrTiO3 compounds show that LaMnO3 and SrTiO3 compounds are insulator and antiferromagnetic and paramagnetic, respectively, but The 2DEG half-metallic observed in (LaMnO3)1/(SrTiO3)4, (LaMnO3)2/(SrTiO3)4, (LaMnO3)3/(SrTiO3)4 superlattices by inclusion of electron-electron correlations with UTi=4.98 eV and UMn=3.5 eV.  We used Stoner-Wolfarth model to investigate the magnetic configuration of (LaMnO3)1/(SrTiO3)8, (LaMnO3)2/(SrTiO3)8, (LaMnO3)3/(SrTiO3)8 superlattices.  The results of density of states show that (LaMnO3)1/(SrTiO3)8, (LaMnO3)2/(SrTiO3)8, (LaMnO3)3/(SrTiO3)8 superlattices are ferromagnetic and half-metallic that are in good agreement with the Stoner-Wolfarth results.