Solitary wave solutions of coupled boussinesq equation

This article presents the general case‐study of our previous works regarding generalized Boussinesq equations [17, 18, 19], that focus on application of various subordinate methods where are applied to construct more general exact solutions of the coupled Boussinesq equations. In this article, the ‐expansion method is applied on coupled Boussinesq equations. Our work is motivated by the fact that the ‐expansion method provides not only more general forms of solutions but also periodic, solitary waves, and rational solutions. The method appears to be easier and faster by means of a symbolic manipulation program. © 2016 Wiley Periodicals, Inc. Complexity 21: 151–155, 2016     

A novel isocyanide-based three-component reaction: synthesis of highly substituted 1,6-dihydropyrazine-2,3-dicarbonitrile derivatives

A novel multi-component synthesis of highly substituted 1,6-dihydropyrazine-2,3-dicarbonitrile derivatives starting from simple and readily available inputs is described. Thus, simply stirring an ethanol solution of 2,3-diaminomaleonitrile, a ketone, and an isocyanide in the presence of a catalytic amount of p-toluenesulfonic acid provided highly substituted 1,6-dihydropyrazine-2,3-dicarbonitrile derivatives in good to excellent yields at ambient temperature.     

Fluorescent Indolo[3,2-a]phenazines against Toxoplasma gondii: Concise Synthesis by Gold-Catalyzed Cycloisomerization with 1,2-Silyl Migration and ipso-Iodination Suzuki Sequence

A gold-catalyzed cycloisomerization of 2-indolyl-3-[(trimethylsilyl)ethynyl)]quinoxalines with concomitant 1,2-silyl shift forms 6-(trimethylsilyl)indolo[3,2-a]phenazines in moderate to excellent yield. These silylated heterocycles are readily transformed into 6-aryl-indolo[3,2-a]phenazines in moderate to good yield by one-pot ipso-iodination Suzuki coupling. The title compounds represent a novel type of tunable luminophore. Structure-property relationships for 6-aryl-indolo[3,2-a]phenazines obtained from Hammett correlations with σ_p+ substituent parameters indicate that emission maxima, Stokes shifts, and fluorescence quantum yields can be fine-tuned by the remote para-aryl substituent. Furthermore, indolo[3,2-a]phenazines were found to exhibit interesting activities against medically relevant pathogens such as the Apicomplexa parasite Toxoplasma gondii with an IC₅₀ of up to 0.67±0.13 μM. Thus, these compounds are promising candidates for novel anti-parasitic therapies.     

Synthesis,characterization and extraction properties of calix[4]crown with amine units and study of its complexes with Cu(II)

In this work, we have focused on the synthesis of p-tert-butyl calix[4]crown with amine units (H ₃ L) as a class of selective receptors for metal ions. The macrocyclic ligand (H ₃ L) with N₂O₇ donors was synthesized via condensation between 1,3-diaminocalix[4]arene and 2-[3-(2-formylphenoxy)-2-hydroxypropoxy] benzaldehyde, followed by reduction of the Schiff base product in situ with sodium borohydride, then it was characterized by FT-IR, ¹H NMR and X-ray crystallography. Two Cu(II) complexes were prepared from the reaction of H ₃ L with Cu(II) salts (CuX₂, X = ClO₄ ^? and Cl^?). FT-IR, UV–Vis, elemental analysis, molar conductivity and cyclic voltammetry techniques were used for study and characterization of these complexes. On the basis of liquid–liquid extraction experiments, ligand H ₃ L indicated good affinity toward Pb²⁺ and Cu²⁺.     

Indole‐3‐acetic acid and N‐acetyltryptophan corrosion inhibition effects on mild steel in 1 M hydrochloric acid solution

Corrosion inhibition of indole‐3‐acetic acid and N‐acetyl tryptophan on carbon steel was investigated using polarization and electrochemical impedance spectroscopy (EIS). Polarization results revealed that corrosion inhibitors could reduce the rate of cathodic and anodic reactions on metal surface. EIS analysis showed inhibition efficiency of indoles increases by increasing the inhibitor concentration. The maximum inhibition efficiency was 97% and 80% in solutions containing 10 mM indole‐3‐acetic acid and 10 mM N‐acetyl tryptophan, respectively. The adsorption of inhibitors was found to follow Langmuir isotherm. Adsorption and film formation of inhibitors on the metal substrate were confirmed by calculating thermodynamic adsorption parameter (ΔG⁰_ads) and characterization of exposed metals' surface through contact angle measurements. Copyright © 2014 John Wiley & Sons, Ltd.     

Matrices based on meso antibacterial framework

In this paper, the synthesis of three types of porous materials (PMs) (porous Fe₃O₄, MIL-101 metal-organic framework (MOF), and MCM-41 mesoporous silica) by hydrothermal method was performed. The incorporation of Ag nanoparticles (Ag NPs) was carried out after the synthesis reaction of supports in MCM-41 and MIL-101 MOF. Ag core@ porous Fe₃O₄ core–shell system was prepared via a one-pot hydrothermal method. Ag-MIL-101 was obtained using Urtica dioica leaf extract as the green solvent and reducing agent. The antibacterial activity of Ag-PM nanocomposites (NCs) was investigated on both Gram-negative and Gram-positive bacteria. The size of the silver NPs was determined to be 12 and 30 nm in MCM-41 and MIL-101 MOF, respectively. The diameter of Ag core in Ag@Fe₃O₄ shell was ~135 nm. The antibacterial activity of Ag-PMs was in the order Ag-MCM-41 > Ag-MIL-101 > Ag core@Fe₃O₄ shell. The loading percent of Ag NPs in MCM-41 (84%) was more than that in MIL-101 (53%) and Fe₃O₄ (31%). The release of Ag⁺ ions from Ag-MCM-41, Ag-MIL-101, and Ag@Fe₃O₄ NCs was 46, 2, and 1 ppm, respectively. The release of the Ag⁺ ions and, consequently, the antibacterial activity of NCs depend on the uniform distribution, particles size, and the absence of aggregation of Ag NPs in PMs.     

Synthesis of functionalized iminolactones via an isocyanide-based three-component reaction

A three-component reaction of the zwitterions generated from isocyanides and dialkyl acetylenedicarboxylate with 1-(4-bromophenyl)-2-thiocyanatoethanone or 1-phenyl-2-thiocyanatoethanone is described. The reaction afforded the corresponding special type of functionalized iminolactone derivatives in good yields at room temperature without using a catalyst.     

Synthesis of a New Class of Highly Functionalized Phosphorus Ylides Containing Heterocyclic Compounds

The zwitterionic intermediate generated from the reaction of triphenylphosphine with electron deficient acetylenic compounds was trapped by various NH acids. The synthesis resulted in a new class of highly functionalized heterocyclic compounds. Some of the reactions produced E and Z isomers. And the stability and transformation of them were studied by dynamic ¹H NMR and density functional theory (DFT) calculations.     

源自水稻壳的高比表面纳米二氧化硅负载12-磷钨酸:一种高效纳米催化剂用于几种有机反应(英文)

Nano silica was prepared from rice husk with high surface area.X-ray diffraction(XRD) pattern showed that the amorphous form of silica was produced.Chemical composition of the nano silica was estimated by X-ray fluorescence spectroscopy and CHN analysis.The nano silica was used as a support for H3PW12O40.The nano silica and nano silica supported H3PW12O40 were characterized by inductively coupled plasma,XRD,transmission electron microscopy(TEM),N2 adsorption-desorption,and Fourier transform infrared spectroscopy.TEM images of nano silica as well as the supported catalyst displayed average size of 6 and 7 nm,respectively.The catalyst showed excellent activity in some important organic reactions including Biginelli,Hantzsch,Mannich,and Claisen-Schmidt reactions with good reusability.Catalytic activity of this nano catalyst is an improvement over the commercially available silica that is used to support H3PW12O40.