Zinc‐containing ionic liquid as a dual solvent‐catalyst in base‐free condensations under ultrasonic irradiation

In this study, natural‐based ionic liquid (IL) using caffeine (Caff), trietahnolamine (TEA) and ZnBr₂, [Caff‐TEA]⁺[ZnBr₃]^?, which features high catalytic activity and environmentally‐friendly nature was synthesized with melting point of 76 °C by a facile method. The synthesized [Caff‐TEA]⁺[ZnBr₃]^? has high catalytic activity as both of catalyst and solvent in condensation reactions for the synthesis of benzylidenes, bis‐hydroxyenones and xanthenes. Synthesized IL was characterized by proton nuclear magnetic resonance (¹HNMR), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD) and Energy‐dispersive X‐ray spectroscopy (EDX) analysis. Also synthesized heterocycles were characterized by FT‐IR, proton nuclear magnetic resonance (¹HNMR) and carbon nuclear magnetic resonance (¹³CNMR).     

Ag3[PMo12O40]: An efficient and green catalyst for the synthesis of highly functionalized pyran‐annulated heterocycles via multicomponent reaction

A facile, efficient and eco‐friendly catalytic protocol was developed for the synthesis of medicinally important pyran‐annulated heterocycles via multicomponent reaction (MCR). Cyclocondensation of differently substituted aromatic aldehydes, malononitrile/ethyl cyanoacetate and various β‐dicarbonyl compounds in the presence of Ag₃[PMo₁₂O₄₀]?nH₂O as heterogeneous catalyst, in EtOH–H₂O, afforded diverse pyran‐fused chromene analogues. The merits observed for this approach were it being conducted via MCR, using commercially available or easily accessible starting materials in the presence of a green and easily separable heterogeneous and reusable catalyst, and affording high yields of desired products in very short reaction times with high purity in one‐pot fashion, thus providing a superior alternative approach for the synthesis of pyran‐annulated heterocycles.     

Estimation of viscosities of 1-alkyl-3-methylimidazolium ionic liquids over a range of temperatures using a simple correlation

In this study, a new correlation is proposed for estimating 1-alkyl-3-methylimidazolium ionic liquid (IL) viscosities at different temperatures and atmospheric pressure. Since ILs are rather novel, many of their physical properties are still unavailable. Because of this limitation, the aim of this work was to propose a correlation with a new insight and approach, which requires a minimum number of physical properties as input parameters. In addition to minimal dependency on physical properties, further goals in the development of the model were generality, ease-of-use, simplicity and high accuracy. A total of 2073 literature viscosity datapoints at different temperatures for 38 different ILs were used and a correlation was developed which satisfied the above-mentioned goals. The IL viscosity models of Lazzús and Pulgar-Villarroel, and Gardas and Coutinho were compared to the proposed correlation. More reliable results were obtained by the proposed relation in comparison to literature models.     

The Processing of Pyrolysis Fuel Oil by Dielectric Barrier Discharge Plasma Torch

In present paper, an atmospheric-pressure low-temperature plasma treatment of pyrolysis fuel oil (PFO) was investigated in dielectric barrier discharge plasma torch reactor. The effect of the applied voltage and the volume of feedstock, as the main parameters, on the cracking of PFO were studied. By increasing the applied voltage from 10 to 16 kV, the production rate of hydrocarbons containing methane, ethylene, acetylene, propane, propylene, and C₄ rise 18 times. In this case, the production rate of hydrogen increases by approximately 14 times and reaches 7.27 × 10^?3 mol/min for 16 kV. In the feedstock volume investigation, based on limitation of reactor volume, the production rate of hydrocarbons decreased from 0.44 × 10^?3 to 0.15 × 10^?3 mol/min by increasing volume of feedstock from 1 to 5 cc.     

One‐pot,four‐component synthesis of 1,3,4‐oxadiazole derivatives containing a ferrocene unit and their antimicrobial activity

A four‐component reaction between aromatic carboxylic acids, (N‐isocyanimino)triphenylphosphorane, ferrocenecarbaldehyde and dibenzylamine is reported. This approach is an efficient, simple and high‐yield procedure for the synthesis of 1,3,4‐oxadiazole derivatives containing a ferrocene unit. The antimicrobial activities of the products were investigated against Staphylococcus aureus and Pseudomonas aeruginosa in in vitro and in vivo assays. Copyright © 2015 John Wiley & Sons, Ltd.     

Simultaneous removal of Cu2+ and Cr3+ ions from aqueous solution based on Complexation with Eriochrome cyanine‐R and derivative spectrophotometric method

TiO₂ nanoparticles deposited on activated carbon (TiO₂–NP–AC) was prepared and characterized by XRD and SEM analysis. Subsequently, simultaneous ultrasound‐assisted adsorption of Cu²⁺ and Cr³⁺ ions onto TiO₂‐NPs‐AC after complexation via eriochrome cyanine R (ECR) has been investigated with UV–Vis and FAA spectrophotometer. Spectra overlapping of the ECR‐Cu and ECR‐Cr complex was resolve by derivative spectrophotometric technique. The effects of various parameters such as initial Cu²⁺ (A) and Cr³⁺ (B) ions concentrations, TiO₂‐NPs‐AC mass (C), sonication time (D) and pH (E) on the removal percentage were investigated and optimized by central composite design (CCD). The optimize conditions were set as: 4.21 min, 0.019 mg, 20.02 and 13.22 mg L^?1 and 6.63 for sonication time, TiO₂–NP–AC mass, initial Cr³⁺ and Cu²⁺ ions concentration and pH, respectively. The experimental equilibrium data fitting to Langmuir, Freundlich, Temkin and Dubinin–Radushkevich models show that the Langmuir model is a good and suitable model for evaluation and the actual behavior of adsorption process and maximum adsorption capacity of 105.26 and 93.46 mg g^?1 were obtained for Cu²⁺ and Cr³⁺ ions, respectively. Kinetic evaluation of experimental data showed that the adsorption processes followed well pseudo second order and intraparticle diffusion models.     

Effects of nitrogen-containing functional groups of reduced graphene oxide as a support for Pd in selective hydrogenation of cinnamaldehyde

Research on Chemical Intermediates - The importance of electronic and chemical properties of nitrogen-doped reduced graphene oxide (NRGO) has attracted more attention in recent years. Various...     

Self-assembly mechanism of PEG-b-PCL and PEG-b-PBO-b-PCL amphiphilic copolymer micelles in aqueous solution from coarse grain modeling

We followed the self-assembly of high-molecular weight MePEG- b -PCL (poly(methyl ethylene glycol)-block-poly(ε-caprolactone)) diblock and MePEG- b -PBO- b -PCL (poly(methyl ethylene glycol)-block-poly(1,2-butylene oxide)-block-poly(ε-caprolactone)) into micelles using molecular dynamics simulation with a coarse grain (CG) force field based on quantum mechanics (CGq FF). The triblock polymer included a short poly(1,2-butylene oxide) (PBO) at the hydrophilic-hydrophobic interface of these systems. Keeping the hydrophilic length fixed (MePEG₄₅), we considered 250 chains in which the hydrophobic length changed from PCL₄₄ or PBO₆- b -PCL₄₃ to PCL₆₂ or PBO₉- b -PCL₆₁. The polymers were solvated in explicit water for 2 μs of simulations at 310.15 K. We found that the longer diblock system undergoes a morphological transition from an intermediate rod-like micelle to a prolate-sphere, while the micelle formed from the longer triblock system is a stable rod-like micelle. The two shorter diblock and triblock systems show similar self-assembly processes, both resulting in slightly prolate-spheres. The dynamics of the self-assembly is quantified in terms of chain radius of gyration, shape anisotropy, and hydration of the micelle cores. The final micelle structures are analyzed in terms of the local density components. We conclude that the CG model accurately describes the molecular mechanisms of self-assembly and the equilibrium micellar structures of hydrophilic and hydrophobic chains, including the quantity of solvent trapped inside the micellar core.