Modification of nano-clays with ionic liquids for the removal of Cd (II) ion from aqueous phase

The present study attempts to synthesize nano-modified clays of Na-bentonite (Bent) and montmorillonite (MT), using three imidazolium-based ionic liquids (ILs) including 3,3′-(hexyl)bis(3-methylimidazolium) bromide chloride ([H(mim)2[Br][Cl]), 1-hexyl-3-methylimidazolium chloride ([Hmim][Cl]) and 1-octyl-3-methylimidazolium chloride ([Omim][Cl]). X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), carbon, hydrogen and nitrogen elemental analysis (CHN), scanning electron microscope (SEM) and specific surface area (SSA) (using N2-BET) techniques provided evidence of successful modification of the guest clays. Removal of Cd (II) from aqueous phase was investigated using the modified clays under different experimental conditions of reaction time, pH and adsorbent dosage. Detailed isotherms and kinetic studies showed that the modified clays have much higher Cd (II) adsorption capacity compared to those of the starting clay minerals. The maximum Cd (II) absorption capacities of 87.46 and 94.6 mg g−1 were observed in [H(mim)2]-MT and [H(mim)2]-Bent with d-values of 35.4 Å and 28.3 Å respectively. The [Omim]-clays had the highest adsorption affinities of Cd (II) in initial concentrations of Cd (II). This study shows that ILs could enhance the clay capacity and tendency for Cd (II) absorption with different trends based on the ILs structures. The modified clays using ILs are green and eco-friendly adsorbents and due to substantial increase in their capacity for the removal of heavy metals, they could have positive economic and environmental impacts

Electrochemical alcohols oxidation mediated by N-hydroxyphthalimide on nickel foam surface

Alcohol to aldehyde conversion is a critical reaction in the industry. Herein, a new electrochemical method is introduced that converts 1 mmol of alcohols to aldehydes and ketones in the presence of N-hydroxyphthalimide (NHPI, 20 mol%) as a mediator; this conversion is achieved after 8.5 h at room temperature using a piece of Ni foam (1.0 cm2) and without adding an extra-base or a need for high temperature. Using this method, 10 mmol (1.08 g) of benzyl alcohol was also successfully oxidized to benzaldehyde (91%) without any by-products. This method was also used to oxidize other alcohols with high yield and selectivity. In the absence of a mediator, the surface of the nickel foam provided oxidation products at the lower yield. After the reaction was complete, nickel foam (anode) was characterized by a combination of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and spectroelectrochemistry, which pointed to the formation of nickel oxide on the surface of the electrode. On the other hand, using other electrodes such as Pt, Cu, Fe, and graphite resulted in a low yield for the alcohol to aldehyde conversion

Novel one-pot four-component condensation cyclization reactions for the synthesis of thiazolidine-4-one and 3<i>H</i>-thiazoles

<p>A novel, simple and efficient synthetic protocol has been developed for the synthesis of a series of thiazolidine-4-one and 3<i>H</i>-thiazole derivatives <i>via</i> a one-pot four-component condensation-cyclization reaction of hydrazine with allyl isothiocyanate and an α-haloketone in the presence of various aldehydes. This new protocol produces novel thiazolidine-4-one and 3<i>H</i>-thiazole derivatives in excellent yields. The remarkable features of this methodology are high yields, easy work-up and a one-pot simple reaction method.</p

A novel synthesis of highly stable palladium nanoparticles and their application in the reduction of nitroaromatic compounds

Herein, a mild and efficient method for synthesis of highly stable palladium nanoparticles (PdNPs) on Aristolochia Olivieri (AO) extract as a support and reducing agent is described. Investigation of catalytically activity of obtained catalyst (AO@PdNPs) was performed for the reduction of nitroaromatic compounds. Of note are the functional group tolerance, fast rate, and the ability to apply a scope of nitro compounds (up to 30). The synthesized catalyst was characterized with UV−visible spectra, FE-SEM, EDS, XRD, AAS, FT-IR, and TEM techniques. The corresponding amine product was obtained excellent to high yields. The catalytic activity of AO@ PdNPs for the hydrogenation of 4-methyl-2-nitroaniline and 4-methoxy-2-nitroaniline was pursued by UV-visible spectroscopy which presented excellent activity of catalyst

Novel β-Cyclodextrin Functionalized Core-Shell Fe3O4 Magnetic Nanoparticles for the Removal of Toxic Metals from Water

Herein we report the synthesis and characterization of β-CD functionalized core-shell Fe3O4 magnetic nanoparticles which were used as an adsorbent for removal of Lead (II) and Copper (II) ions from aqueous solution. Various characterization techniques including FTIR, TGA analysis, SEM, TEM, X-Ray diffraction patterns (XRD) and nitrogen adsorption- desorption measurements were employed to investigate the properties of the synthesized material. The influence of pH, contact time, metal ion concentration, adsorbent dosage of Lead (II) and Copper (II) ion removal were also studied. The isotherm models for both ions showed a fit to the Langmuir model. Thermodynamic parameters such as enthalpy, entropy and Gibbs free energy were also evaluated and the negative values of ΔH for both Lead (II) and Copper (II) ions indicated the exothermic nature their sorption

Manganese oxide nanoparticles supported on graphene oxide as an efficient nanocatalyst for the synthesis of 1,2,4‐oxadiazoles from aldehydes

The easy synthesis of graphene oxide (GO)‐supported manganese dioxide (MnO2) nanoparticles as a stable heterogeneous nanocatalyst (MnO2@GO) is described. This catalyst was investigated in the synthesis of 1,2,4‐oxadiazoles from amidoximes and aldehydes via a cyclization and oxidation process. The nanocomposite was prepared and characterized using various techniques. The catalytic application of the nanocomposite was examined in the reaction of a variety of aldehydes with aliphatic and aromatic amidoximes. The stable and robust catalyst was recycled for seven consecutive runs without a significant decrease in the catalytic activity.The authors are grateful to the Research Council of University of Zanjan, Institute for Advanced Studies in Basic Sciences (IASBS), the University of British Columbia, the University of Alicante (VIGROB-173) and the Spanish Ministerio de Economía, Industria y Competitividad (CTQ2015-66624-P) for support of this work

Oxidation of alkylarenes by modified graphite

Oxidation of alkylarenes by modified graphit

Synthesis of phosphorothioates using thiophosphate salts

Reactions of O,O'-dialkyl thiophosphoric acids with alkyl halides, in the presence of a base, provide a direct synthetic route to phosphorothioates via O,O'-dialkyl thiophosphate anion formation. Studies on the reaction of ambident nucleophile ammonium O,O'-diethyl thiophosphate with benzyl halides and tosylate in different solvents show that only S-alkylation is obtained. Reaction of this ambident nucleophile with benzoyl chloride (a hard electrophile), gave the O-acylation product. A simple, efficient, and general method has been developed for the synthesis of phosphorothioates through a one-pot reaction of alkyl halides with the mixture of diethyl phosphite in the presence of triethylamine/sulfur/and acidic alumina under solvent-free conditions using microwave irradiation