A Quick and Clean Procedure for Synthesis of α‐Aminophosphonates in Aqueous Media

A green and efficient procedure for the synthesis of α‐aminophosphonates has been developed in water as a green and nonhazardous solvent, from condensation between aromatic aldehydes, aniline, and triphenyl phosphite at 80°C. This methodology has a number of advantages including clean reaction conditions, easy work‐up, and environmentally friendly.     

Quantum computation of the properties of helium using two-body and three-body intermolecular potentials: a molecular dynamics study

We have performed the molecular dynamics simulation to obtain energy, pressure, and self-diffusion coefficient of helium at different temperatures and densities using Lennard–Jones (LJ), Hartree–Fock dispersion-Individual damping (HFD-ID) potential, and the HFD-like potential which has been obtained with an inversion of viscosity data at zero pressure supplemented by quantum corrections following the Feynman–Hibbs approach. The contribution of three-body interactions using an accurate simple relationship reported by Wang and Sadus between two-body and three-body interactions has been also involved for non-effective potentials (HFD-ID and HFD-like) in simulation. Our results show a good agreement with corresponding experimental data. A comparison of our simulated results with other molecular simulations using different potentials is also included.     

The Reaction of N-Isocyaniminotriphenylphosphorane with Cyclopentanone and A Primary Amine in the Presence of An E-Cinnamic Acid Derivative

Abstract

Reactions of N-isocyaniminotriphenylphosphorane with cyclopentanone in the presence of an E-cinnamic acid derivative and a primary amine proceeds smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions were observed.     

Plasma and KMnO4 Oxidation of Polyacrylonitrile Nanofiber

The effect of plasma and chemical methods on the stabilization of Polyacrylonitrile (PAN) nanofiber prepared by electrospinning technique, has been investigated at various oxygen contents (10%, 20%, and 30%) and KMnO₄ solutions (3% and 5%). Fourier transform infrared (FT-IR) analysis of plasma and chemical oxidized samples indicated that the treated nanofibers were oxidized under different contents of oxygen plasma and KMnO₄ contents by increasing the peak intensities of C&dbnd;O stretching band and OH– stretching vibration mode, respectively. Additionally conversion of C≡N bands into C&dbnd;N ones in the copolymer chain was observed in both plasma and chemical methods, but changes in chemical stabilized samples were not very sensible. Field emission scanning electron microscopy (FE-SEM) images revealed that the surfaces of the plasma treated nanofibers were extremely etched. Furthermore a higher reduction in the average oxidized nanofiber diameters was observed using plasma method.     

One‐step Hydrothermal Synthesis and Assembly of Copper and Silver Nanoparticles to Aggregates in Glyoxal Reduction System

A simple hydrothermal process has been developed for the synthesis and assembly of copper and silver nanoparticles to aggregates. The reduction of Cu²⁺ and Ag⁺ ions to the zerovalent metal was performed by glyoxal in the absence of any external agent. The produced glyoxylic acid (GA) in the redox process stabi‐ lized metallic copper and silver particles and rendered them oxidation resistant for several months and dispersible in polar organic solvents and water. Detailed nanostructures of synthesized products were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD). The results demonstrated that assembly of nanoparticles to aggregates and their regularity were dependent on the reaction conditions such as temperature and concentration of the starting material. The Ostwald ripening process was proposed to explain the formation of copper nanoparticles by TEM observation at several times during the reaction. The existence of the surface stabilizing agent was identified by Fourier Transform infrared spectroscopy (FT‐IR) and thermogravimetric analyses (TGA).     

Crystal structures and in vitro anticancer studies on new unsymmetrical copper(II) Schiff base complexes derived from meso-1,2-diphenyl-1,2-ethylenediamine: a comparison with related symmetrical ones

Two new unsymmetrical copper(II) Schiff base complexes, [CuLⁿ(py)]ClO₄ (n = 1, 2) in which Lⁿ represents a tridentate N₂O type Schiff base ligand, were synthesized. Lⁿs were derived from monocondensation of meso-1,2-diphenyl-1,2-ethylenediamine with salicylaldehyde or 3-methoxysalicylaldehyde. The reaction between [CuLⁿ(py)]ClO₄ and other salicylaldehyde derivatives resulted in new N₂O₂ unsymmetrical tetradentate Cu^II complexes, CuL^3–6. Crystal structures of [CuL¹(py)]ClO₄, CuL⁴, and CuL⁵ were obtained. These new complexes as well as a series of related symmetrical ones (i.e. CuL^7–12) were tested for their in vitro anticancer activity against human liver cancer cell line (Hep-G2) by MTT and apoptosis assay. All of the complexes showed considerable cytotoxic activity against tumor cell lines (IC₅₀ = 5.13–16.24 μg mL^?1). The symmetrical CuL⁷ was the most potent anticancer derivative (IC₅₀ = 5.13 μg mL^?1) compared to the control drug 5-FU (IC₅₀ = 5.4 μg mL^-1, p < 0.05). Flow cytometry experiments showed that the copper derivatives especially [CuL²(py)]ClO₄ and CuL⁷ induced more apoptosis on Hep-G2 tumor cell lines compared to 5-FU.     

Elucidation of diazinon metabolites in rice plants by liquid ‎chromatography ion-trap mass spectrometry

ABSTRACT

A fast, selective and sensitive reversed-phased liquid chromatography coupled to ion-trap mass spectrometry has been developed to elucidate and confirm the diazinon metabolites with a wide range of polarity in the rice plant samples. Sample extraction and purification were performed with a QuEChERS-based (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure. To boost all metabolism sensitivities, all rice extracts were concentrated under vacuum to near dryness and taken up into initial mobile phase. Careful optimisation of the LC–MS/MS parameters were achieved in order to attain a fast separation with the best sensitivity. The detection was carried out on an ion-trap mass spectrometer by electrospray ionisation in positive ion mode (ESI+) with multiple reaction monitoring.