Green synthesis of some 3-(α,α-diarylmethyl)indoles by bio-nanocomposite from embedding L–histidinium trichloroacetate ionic liquid on functionalized magnetite (L–His+CCl3CO2−@PEG@SiO2–nano Fe3O4)

Molecular Diversity - In this research, a new multilayered magnetized bio-nanocomposite has been prepared. At first, the amino acid-based ionic liquid was obtained from L-histidine and...     

Determination of hydrate inhibitor in crude oil by nanoextraction-gas chromatography

This work focused on the quantitation of methanol as a hydrate inhibitor in crude oil. The novelty is nanoextraction of a polar compound from a complex non-polar matrix and selection of the proper fiber with maximum selectivity, loading percent, and lifetime. This approach not only does not require specific instrumentation, such as multiple columns and selective detectors, but also has eliminated the use of organic solvent and avoids the insertion of water inside the GC columns. The objective is optimization of extraction conditions, GC adjustments, and data processing. Experiments were conducted on the real sample of Iranian offshore crude oil by a carboxen/PDMS fiber via GC equipped with a cross-linked polyethylene glycol column and flame ionization detector. The results revealed that this fiber adsorbed the alcohols among other light non-polar compounds of crude oil. Moreover, the interference effects of ethanol were solved by proper selection of the thermal program. The LOD, LOQ, and linear range of this approach were determined to be 3.9, 12.9, and 14-229 ppm for methanol, respectively. Using the standard calibration and the standard addition methods, the relative errors of 1.6-7.2 and 5.3-14.0% were determined.     

A method based on meshless approach for the numerical solution of the two‐space dimensional hyperbolic telegraph equation

In the current article, we investigate the RBF solution of second‐order two‐space dimensional linear hyperbolic telegraph equation. For this purpose, we use a combination of boundary knot method (BKM) and analog equation method (AEM). The BKM is a meshfree, boundary‐only and integration‐free technique. The BKM is an alternative to the method of fundamental solution to avoid the fictitious boundary and to deal with low accuracy, singular integration and mesh generation. Also, on the basis of the AEM, the governing operator is substituted by an equivalent nonhomogeneous linear one with known fundamental solution under the same boundary conditions. Finally, several numerical results and discussions are demonstrated to show the accuracy and efficiency of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.     

Oxidation of Benzylic Hydrocarbons to Carbonyl Compounds by Tetrapyridinesilver(II) Peroxydisulfate Ag(Py)4S2O8 Under Non-Aqueous and Aprotic Condition

Different benzylic hydrocarbons are oxidized by tetrapyridinesilver(II) peroxydisulfate in refluxing acetonitrile to produce their corresponding carbonyl compounds in moderate to excellent yields.     

New complexes of Ni(II) and Cu(II) with tridentate ONO Schiff base ligand: synthesis,crystal structures,electrochemical and theoretical investigation

In this research, we prepared a new series of the Cu(II) (1) and Ni(II) (2) metal complexes of a tridentate Schiff base ligand, (E)-2-(5-bromo-2-hydroxybenzylideneamino) phenol (H₂L). These complexes were characterized by elemental analysis, FT-IR, UV–Vis, and ¹H-NMR spectroscopy. The crystal structures of (1) and (2) were determined by X-ray diffraction studies. The single crystal X-ray diffraction analyses revealed that copper(II) cation is five-coordinated and the coordination polyhedron is a slightly distorted square pyramid. Nickel(II), on the other hand, is four-coordinated, and has a regular, square planar geometry. Further discussed were the electrochemical reduction of these complexes. We also analyzed the nature of the metal–ligand bond in the complexes through NBO and EDA analysis. Besides, vibrational sample magnetometer (VSM) revealed complex (1) was ferromagnetic.     

Surfactant‐assisted electromembrane extraction combined with capillary electrophoresis as a novel technique for the determination of acidic drugs in biological fluids

In this paper, for the first time, surfactant‐assisted electromembrane extraction coupled with capillary electrophoresis with UV detector was introduced for the extraction of acidic drugs from biological fluids. In this technique, in the presence of the nonionic surfactant in the donor phase, tendency of analyte ions into the supported liquid membrane (SLM) was increased. Naproxen and diclofenac were selected as model acidic drugs. In order to obtain the best extraction efficiency, several factors influencing the extraction efficiency were investigated. Optimal extractions were accomplished with 1‐octanol as the SLM, 15 Volt dc potential as the driving force, pH 12 in acceptor solution, and 0.2 mmol/L Triton X‐100 with pH 7.4 in donor solution. Equilibrium extraction conditions were obtained after 15 min of operation where the whole assembly agitated at 1000 rpm. Under the optimized conditions, preconcentration factors in the range of 176–184 and recoveries in the range of 88–92% were obtained. The applied method offers acceptable linearity with correlation coefficients higher than 0.9992. Limits of detection of 1.51 ng/mL and 2.42 ng/mL were obtained for naproxen and diclofenac, respectively. Finally, the developed method was successfully applied for the determination of naproxen and diclofenac in different matrices including plasma and urine samples.     

New Convenient Five‐Component One‐Pot Synthesis of 3‐Alkyl‐6‐amino‐1,4‐dihydro‐4‐{[(1,2,3‐triazol‐4‐yl)methoxy]phenyl}pyrano[2,3‐c]pyrazole‐5‐carbonitrile Derivatives

3‐Alkyl‐6‐amino‐1,4‐dihydro‐4‐{[(1,2,3‐triazol‐4‐yl)methoxy]phenyl}pyrano[2,3‐c]pyrazole‐5‐carbonitrile derivatives were synthesized through a one‐pot five‐component condensation reaction.     

Rheological and transport properties of sulfonated polyacrylamide hydrogels for water shutoff in porous media

In this research, an optimal hydrogel, based on sulfonated polyacrylamide, was synthesized by statistical design of experiments using central composite method. This new hydrogel composed of sulfonated polyacrylamide (AN125VLM) and chromium triacetate as copolymer and crosslinker, respectively. The bottle and rheological tests were conducted to investigate the gelation time, thermal stability, gel strength and also ultimate elastic modulus, complex modulus, and yield stress. It was found that copolymer concentration had the main effect in both rheological and transport properties of hydrogels. The sample prepared at optimum condition, i.e. copolymer concentration of 26,340 ppm and crosslinker/copolymer ratio of 0.12, had an ultimate elastic modulus of 29.9 kPa, yield stress of 800 Pa, and complex modulus of 32 kPa. A coreflooding test through fracture was carried out to examine the optimum gel performance in a porous media. A value of 483 for the residual resistance factor ratio of water to oil confirmed the high ability of the hydrogel in reducing the relative permeability of water to oil in fractured media. Copyright © 2014 John Wiley & Sons, Ltd.     

Encapsulation of Pd(II) into superparamagnetic nanoparticles grafted with EDTA and their catalytic activity towards reduction of nitroarenes and Suzuki–Miyaura coupling

A robust, safe and magnetically recoverable palladium catalyst was synthesized by anchoring Pd(II) onto ethylenediaminetetraacetic acid‐coated Fe₃O₄ (Fe₃O₄@EDTA) magnetic nanoparticles. The Fe₃O₄ magnetic nanoparticle‐supported Pd(II)–EDTA complex catalyst thus obtained was characterized using scanning and transmission electron microscopies, thermogravimetric analysis, vibrating sample magnetometry, X‐ray diffraction, and inductively coupled plasma atomic emission and Fourier transform infrared spectroscopies. Fe₃O₄@EDTA–Pd(II) was screened for the Suzuki reaction and reduction of nitro compounds in water. The Pd content of the catalyst was measured to be 0.28 mmol Pd g^?1. In addition, the Fe₃O₄@EDTA–Pd catalyst can be easily separated and recovered with an external permanent magnet. The anchored solid catalyst can be recycled efficiently and reused five times with only a very slight loss of catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.     

A practical and versatile approach toward a one-pot synthesis of 2,3-disubstituted 4(3H)-quinazolinones

Abstract  

An effective one-pot three-component route to 4(3H)-quinazolinones from commercially available starting materials is reported. Thus, isatoic anhydride reacted with ammonium acetate or primary amines and aldehydes in the presence of iodine to produce the corresponding quinazolinone derivatives in moderate to good yields.