Synthesis,crystal structure,cholinesterase inhibitory activity,evaluation of insecticidal activities,and computational studies of new phosphonic acids

Molecular Diversity - In an attempt to obtain the modified and novel insecticides with low human toxicity, a series of novel mono-, bis-, and tetraphosphonic acid derivatives were designed and...     

Facile method for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by SiO2–H3PW12O40 in water

Research on Chemical Intermediates - The 12-tungstophosphoric acid supported on silica gel (PW/SiO2) exhibits excellent activity in the synthesis of 2,3-dihydroquinazolin-4(1H)-ones by...     

Impact of modified electrodes on boosting power density of microbial fuel cell for effective domestic wastewater treatment:A case study of Tehran

Utilizing microbial fuel cells (MFCs) is a promising technology for energy-efficient domestic wastewater treatment, but it still faces practical barriers such as low power generation. In this study, the LaMnO₃ perovskite-type oxide nanoparticles and nickel oxide/carbon nanotube/polyaniline (NCP) nanocomposite (the cathode and anode catalysts, respectively) have been prepared and used to enhance power density of MFC. The prepared La-based perovskite oxide catalysts were characterized by X-ray diffraction (XRD) and scanning electron microscopies (SEM). The electrocatalytic properties of the prepared catalysts were investigated through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) and Tafel plot at ambient temperature. Results show the exchange current densities of LaMnO₃/carbon cloth cathode and NCP nanocomposite/carbon cloth anode were 1.68 and 7 times more compared to carbon cloth cathode, respectively. In comparison to the bare carbon cloth anode, the MFC with the modified electrodes shows 11 times more enhancement in power density output which according to electrochemical results, it can be due to the enhancement of the electron transfer capability. These cathodic and anodic catalysts were examined in batch and semi-continuous modes to provide conditions close to industrial conditions. This study suggests that utilizing these low cost catalysts has promising potential for wastewater treatment in MFC with high power generation and good COD removal efficiency.     

Carbon nanotube-based magnetic bucky gels in developing dispersive solid-phase extraction: application in rapid speciation analysis of Cr(VI) and Cr(III) in water samples

In this work, we developed dispersive solid-phase extraction method with the use of carbon nanotube based magnetic bucky gels. The hydrophilic carbon nanotube (CNT)-based magnetic bucky gels (M-BGs) were developed with the features of magnetic susceptibility to permit fast injection of sorbent, rapid retrieval of the sorbent and high dispersion of MWCNT in the aqueous sample. We combined magnetic multi-wall carbon nanotube nanocomposite (MMWCNTs) with hydrophilic ionic liquids in order to prepare highly stable carbon nanotube-based magnetic bucky gels. The hydrophilic ILs act simultaneously as modifier and disperser for MMWCNTs and reduce the agglomeration of sorbent in water .Consequently they enhance the extraction efficiency. We used the unique features of this responsive gel (fluidity, stability, magnetic properties, and strong sorbing ability) in developing a new, fast, sensitive, simple, and environmental-friendly magnetic bucky gel-based dispersive solid-phase extraction method (M-BG-dSPE) combined with fibre optic linear array detection spectrophotometer (FO-LADS) for preconcentration and speciation of Cr(VI) and Cr(III) in water samples. The properties of MMWCNT and magnetic bucky gels were characterised by scanning electron microscopy (SEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and Fourier transform infrared spectrophotometer (FT-IR). Under the optimised conditions, the enrichment factor of the method was 318, the limit of detection was 0.1 ng mL^?1 and the repeatability of the method, expressed as the relative standard deviation (RSD, n = 5), varies between 3.2% and 2.5% in different concentrations. The proposed procedure has been applied for speciation of Cr(VI) and Cr(III) in water samples with good recoveries in the range from 90 to 105%. Validation of the method was carried out by comparison of the obtained results with results obtained by the ET-AAS and spiking-recovery method.     

Nanoammonium salt: a novel and recyclable organocatalyst for one-pot three-component synthesis of 2-amino-3-cyano-4<Emphasis Type="Italic">H</Emphasis>-pyran derivatives

1,3-Propanediaminium methanesulfonate [(PDA)(MeSO₃)] was synthesized as the first nanoaliphatic ammonium salt via a safe and simple chemical route in aqueous media. [(PDA)(MeSO₃)] ammonium salt was characterized by XRD, TEM, SEM, EDS, DLS, AFM, ¹H NMR, ¹³C NMR, FT-IR, TG, and elemental analysis. [(PDA)(MeSO₃)] ammonium salt was efficiently applied as an eco-friendly and recyclable organocatalyst for the one-pot, three-component synthesis of 2-amino-3-cyano-4H-pyran derivatives. From an economical and environmental point of view, this novel catalyst has the merits of environmental friendliness, high yields, shorter reaction time, simple work-up, easy operation, the avoidance of the organic solvents, and inexpensive catalysts.     

Effect of Curcuma longa tuber powder extract on size of silver nanoparticles prepared by green method

Biosynthesis of noble metal nanoparticles is a vast developing area of research. In the present study, silver nanoparticles (Ag-NPs) were synthesized from aqueous silver nitrate through a simple and biosynthetic route using water extract of Curcuma longa (C. longa) tuber powder, which acted simultaneousl as a reductant and stabilizery. The as-prepared samples are characterized using UV–Visible, XRD, TEM, SEM, EDXF, and FT-IR techniques. The formation of Ag-NPs is evidenced by the appearance of the signatory brown color of the solution and UV–vis spectra. Formation of Ag/C. longa was determined by UV–Vis spectroscopy where surface plasmon absorption maxima can be observed at 457–415 nm from the UV–Vis spectrum. The XRD analysis shows that the Ag-NPs are of a face-centered cubic structure. Well-dispersed Ag-NPs with anisotropic and isotropic morphology for 5, 10, and 20 mL of C. longa water extract having a size less than 10 nm are seen in TEM images. The optimum volume extraction to synthesize smallest particle size was 20 mL with mean diameter and standard division 4.90 ± 1.42 nm. FT-IR spectrum indicates the presence of different functional groups in capping the nanoparticles with C. longa. The zeta potential analysis results indicated that the charge of C. longa was negative and increased in Ag/C. longa emulsion with increasing of volumes of extract used (10–20 mL). The most needed outcome of this work will be the development of value-added products from C. longa for biomedical and nanotechnology-based industries.     

Solvent-free synthesis of 6-unsubstituted dihydropyrimidinones using 2-pyrrolidonium bisulphate as efficient catalyst

A one-pot three-component Biginelli-like reaction of enaminones, aldehydes with urea/thiourea in the presence of 2-pyrrolidonium bisulphate as an acidic ionic liquid catalyst for the preparation of 6-unsubstituted dihydropyrimidinones is described. The excellent yield, short reaction time, simple procedure and avoidance of the use of organic solvents are some advantages of this method.     

DIRECT OXIDATIVE DEPROTECTION OF TETRAHYDROPYRANYL ETHERS USING HEXAMETHYLENETETRAMINE-BROMINE SUPPORTED ONTO SILICA GEL UNDER MICROWAVE IRRADIATION IN SOLVENTLESS SYSTEM

Primary and secondary tetrahydropyranyl ethers (THP ethers) are converted to their corresponding carbonyl compounds efficiently using hexamethylene-tetramine-bromine supported onto silica gel under microwave irradiation in solvent-free conditions.     

A novel solid-phase extraction method for separation and preconcentration of zirconium

This work assesses the use of modified natural clinoptilolite as an adsorptive material for separation and preconcentration of trace amounts of zirconium ions. A simple, rapid and economical method was developed for the preconcentration of trace amounts of zirconium in aqueous medium using 1-(2-pyridylazo)-2-naphthol as a complexing agent. Effect of sample pH, flow rate of sample and elution solutions, breakthrough volume and interference of several ions were studied. Determination of zirconium was made by ICP-AES technique. The sorption was quantitative in the pH range from 3.0 to 4.0, whereas quantitative desorption occurred instantaneously with 2 mol L^?1 hydrochloric acid. Linearity was maintained between 0.05 and 9.0 μg mL^?1. Relative standard deviations range from ±0.9% to ±2.3% (n?=?5). The detection limit was 0.1 ng mL^?1. Because of good recovery (>97%), this method is suitable for preconcentration and determination of zirconium in effluents containing trace amount of zirconium.