Natural hydroxyapatite‐supported MnO2: a green heterogeneous catalyst for selective aerobic oxidation of alkylarenes and alcohols

Natural hydroxyapatite‐supported MnO₂ (MnO₂@NHAp) was easily prepared in situ from reduction of potassium permanganate with natural hydroxyapatite derived from cow bones in water at room temperature, and its structure was characterized using flame atomic absorption spectroscopy, X‐ray diffraction, thermogravimetric analysis, scanning electron microscopy and energy dispersive spectroscopy. The catalytic activity of the synthesized catalyst was investigated for the aerobic oxidation of alkylarenes and alcohols. MnO₂@NHAp shows excellent catalytic performance for the oxidation of alkylarenes and alcohols to their corresponding carbonyl compounds without using any other oxidizing agent. This catalyst can be readily recycled and reused for several runs without any significant loss of efficiency. Copyright © 2016 John Wiley & Sons, Ltd.     

Beta-carotene/cyclodextrin-based inclusion complex: improved loading,solubility, stability,and cytotoxicity

Journal of Inclusion Phenomena and Macrocyclic Chemistry - Beta-carotene (BC) is a vitamin A precursor and has potential anticancer benefits, but the delivery of BC is hindered by its low...     

Numerical solutions of Schrödinger wave equation and Transport equation through Sinc collocation method

Nonlinear Dynamics - This paper focuses on finding soliton solutions for an intrinsic fractional discrete nonlinear electrical transmission lattice. Our investigation is based on the fact that for...     

Fe3O4@SiO2@Im‐bisethylFc [HC2O4] as a novel recyclable heterogeneous nanocatalyst for synthesis of bis‐coumarin derivatives

Nanomagnetic bisethylferrocene‐containing ionic liquid supported on silica‐coated iron oxide (Fe₃O₄@SiO₂@Im‐bisethylFc [HC₂O₄]) as a novel catalyst was designed and synthesized. The described catalyst was recycled and used without change in the time and efficiency of the condensation reaction. The Fourier transform‐infrared spectroscopy (FT‐IR), scanning electron microscopy images, X‐ray diffraction patterns, energy‐dispersive X‐ray spectroscopy, transmission electron microscope and vibrating‐sample magnetometer results confirmed the formation of Fe₃O₄@SiO₂@Im‐bisethylFc [HC₂O₄] magnetic nanoparticle. The novel bis‐coumarin derivatives were identified by ¹H‐NMR, ¹³C‐NMR, FT‐IR and CHNS analysis.     

Adsorption of phenols from contaminated water through titania-silica mixed imidazolium based ionic liquid: Equilibrium,kinetic and thermodynamic modeling studies

The present study describes the synthesis and characterization of titania-silica mixed imidazolium based ionic liquid (Ti-Si-IL) as well as evaluation of its adsorption behavior towards the 2,4-dinitrophenol (2,4-DNP) and 2,4,6-trichlorophenol (2,4,6-TCP). Synthesized Ti-Si-IL adsorbent was characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), BET surface area Brunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA) and elemental analysis (CHN). The adsorption of 2,4-DNP and 2,4,6-TCP on Ti-Si-IL was investigated systematically by evaluating the effects of adsorbent dosage, initial pH, contact time and temperature. Satisfactory adsorption 95% and 65% for 2,4-DNP and 2,4,6-TCP was observed at pH 4 and 6, respectively. The kinetic results for 2,4-DNP and 2,4,6-TCP on Ti-Si-IL indicated that the kinetic data follows pseudo-second-order model (R² = 0.9985 and 0.9750, respectively). Adsorption isotherms were fitted well by the Langmuir model for 2,4-DNP (q_m = 44.64 mg g^?1 at 318 K) and Freundlich model for 2,4,6-TCP (K_F = 0.63 mg g^?1 at 318 K). The +ΔH° and -ΔG° values demonstrated that the adsorption of 2,4-DNP was endothermic and spontaneous in nature. While the -ΔH° and +ΔG° values for 2,4,6-TCP adsorption demonstrated exothermic and comparatively nonspontaneous. During the removal process, the role of different functional groups, cyclic structure was monitored and found that the ionic property as well as π-π interactions of host molecules played important role in the extent of adsorption.     

Photocatalytic degradation of carcinogenic Congo red dye in aqueous solution,antioxidant activity and bactericidal effect of NiO nanoparticles

Journal of the Iranian Chemical Society - Face-centered cubic structure of nickel oxide (NiO) nanoparticles with 30 nm average size was synthesized by co-precipitation method with some...     

A solvent-free reaction between acetophenone oximes and epoxy styrenes: an efficient synthesis of 2,4,6-triarylpyridines under neutral conditions

An efficient synthesis of 2,4,6-triarylpyridines is described which involves heating a mixture of an acetophenone oxime and an epoxy styrene under neutral, solvent-free conditions. Kröhnke pyridine products are obtained in excellent yields.     

A Simple Approach to Simultaneous Electroanalytical Quantification of Acetaminophen and Tramadol Using a Boron‐doped Diamond Electrode in the Existence of Sodium Dodecyl Sulfate

The present work describes the individual, selective and simultaneous quantification of acetaminophen (ACP) and tramadol hydrochloride (TRA) using a modification‐free boron‐doped diamond (BDD) electrode. Cyclic voltammetric measurements revealed that the profile of the binary mixtures of ACP and TRA were manifested by two irreversible oxidation peaks at about +1.04 V (for ACP) and +1.61 V (for TRA) in Britton‐Robinson (BR) buffer pH 3.0. TRA oxidation peak was significantly improved in the presence of anionic surfactant, sodium dodecyl sulfate (SDS), while ACP signal did not change. By employing square‐wave stripping mode in BR buffer pH 3.0 containing 8×10^?4 mol L^?1 SDS after 30 s accumulation under open‐circuit voltage, the BDD electrode could be used for quantification of ACP and TRA simultaneously in the ranges 1.0–70 μg mL^?1 (6.6×10^?6–4.6×10^?4 mol L^?1) and 1.0–70 μg mL^?1 (3.3×10^?6–2.3×10^?4 mol L^?1), with detection limits of 0.11 μg mL^?1 (7.3×10^?7 mol L^?1) and 0.13 μg mL^?1 (4.3×10^?7 mol L^?1), respectively. The practical applicability of the proposed approach was tested for the individual and simultaneous quantification of ACP and/or TRA in the pharmaceutical dosage forms.     

Catalytic performance in 4-nitrophenol reduction by Ag nanoparticles stabilized on biodegradable amphiphilic copolymers

Biodegradable copolymers have received much more attention in the last decades due their potential applications in the fields related to environmental protection, medicine, agriculture, and the chemical processes. Silver nanoparticles (Ag NPs) were prepared via reduction of silver nitrate (AgNO₃) using biodegradable amphiphilic copolymers in aqueous solution. The micelles were constructed from the amphiphilic copolymer composed of poly(2-ethyl-2-oxazoline) and poly(ε-caprolactone). The Ag NPs with a diameter of 10–15?nm were found to show a comparable high catalytic activity toward the reduction of 4-nitrophenol (4-NP) in the presence of an excess amount of NaBH₄. The synthesized Ag NPs-loaded copolymer exhibits high catalytic activity for the reduction of 4-NP to 4-aminophenol.     

Adaptive controller design for lag-synchronization of two non-identical time-delayed chaotic systems with unknown parameters

In this Letter, two adaptive controllers are proposed for the lag-synchronization of two non-identical time-delayed chaotic systems with fully unknown parameters. Based on Lyapunov-stability theorem and adaptive techniques, sufficient conditions for the lag-synchronization of these two systems are discussed. Finally, illustrative examples are given to verify the validity of the developed controllers.