meta‐Selective C−H Activation of Arenes at Room Temperature Using Visible Light: Dual‐Function Ruthenium Catalysis

Ruthenium‐catalyzed meta‐C?H activation of arenes at room temperature is reported to proceed under blue‐light irradiation. A variety of heteroarenes are compatible with this photochemical process, which leads to the corresponding meta C?C coupling products in good to very good yields. Initial mechanistic studies suggest a single‐electron transfer process occurs between a photoexcited Ru^II‐cyclometalated complex and alkyl halides, enabling meta‐C?H functionalization reaction via carbon‐centered radicals.     

Fabrication of Nanostructured Self‐Detoxifying Nanofiber Membranes that Contain Active Polymeric Functional Groups

Military soldiers, medicinal doctors, and ordinary people require protection against chemical and biological warfare (C&B) agents. Activated charcoal impregnated with metal ions is currently used in protective clothing applications, which has some disadvantages. Electrospinning is emerging as one of the cheapest technologies to produce continuous nanofibers with a high surface area‐to‐volume ratio. In the present study, electrospinning of a poly(ethylene imine) (PEI)/nylon blend has been carried out in which PEI acts as a support material as well as a catalytic media. The membrane is combined with non‐selective metal oxide nanoparticles to degrade C&B agents into non‐toxic products. In addition, these membranes possess hydrophilic properties, hence they are suitable candidates for protective clothing applications.

     

Determination of traces of rubidium in high purity cesium chloride by electrothermal atomic absorption spectrometry (ETAAS) using boric acid as a modifier

The use of boric acid as a modifier for the determination of trace amount of rubidium in high purity cesium chloride matrix by electrothermal atomic absorption is described. It was found that the negative influence of the chloride matrix could not be eliminated using stabilized temperature platform (STPF) alone. Due to the high dissociation energy (D₀ = 427 kJ mol⁻¹) of rubidium chloride, it was difficult to dissociate in the gas phase and hence is lost. Elimination of interferences was achieved by the addition of boric acid as a chemical modifier. Diluted cesium chloride samples (5%, m/v) were analyzed applying the standard addition method. The characteristic mass of 24 pg was obtained. The detection limit of the proposed method is around 26 ng g⁻¹. The developed method was applied to the determination of traces of rubidium in high purity cesium chloride samples. The data obtained by this method were in good agreement with those obtained by other independent method like FAAS.     

Photoinduced Copper‐Catalyzed Regioselective Synthesis of Indoles: Three‐Component Coupling of Arylamines,Terminal Alkynes,and Quinones

The first successful example of a visible‐light‐induced copper‐catalyzed process for C H annulation of arylamines with terminal alkynes and benzoquinone is described. This three‐component reaction allows use of a variety of commercial terminal alkynes as coupling partners for the one‐step regioselective synthesis of functionalized indoles. Moreover, the current process represents a sustainable and atom‐economical approach for the preparation of complex indoles from easily accessible starting materials under visible‐light irradiation, without the need for expensive metals and harsh reaction conditions.     

Synthesis and thermal properties of spiro phosphorus compounds

Intumescent materials, 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5,5]-undecane-3,9-dioxide and 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5,5]-undecane having the capacity to produce dehydrating agent, blowing agent, and undergo carbonization during burning have been synthesized. The thermal behavior of the synthesized materials was investigated using differential thermal analysis, thermal volatilization analysis, programmed vacuum pyrolysis–mass spectrometry, flash pyrolysis–mass spectrometry and off-line pyrolysis–gas chromatography–mass spectrometry. The materials show exothermic degradation after 250 °C. Monitoring the release of hydrogen chloride and water, the blowing agents for the production of carbon foam, clearly indicated the superior performance of the pentavalent phosphorus compound over the trivalent phosphorus compound. The major gaseous degradation products released during pyrolysis showed the presence of sufficient quantities of several alkyl-substituted benzenes and fused aromatics. Suitable degradation mechanism has been proposed and discussed to explain the formation of various organics during thermal degradation.     

Pricing American options when asset prices jump

We present a transformation that helps price American options on assets that are modeled by a diffusion as well as a jump component. The presence of a jump component circumvents some shortcomings of the Black-Scholes model. The proposed transformation essentially transforms the arising free-boundary partial integro-differential equation (PIDE) into a sequence of fixed-boundary PIDEs which are much easier to solve. Finally, we provide numerical results illustrating convergence of the scheme and comparisons to other methods.     

Binuclear Cu(II) chiral complexes: synthesis,characterization and application in enantioselective nitroaldol (Henry) reaction

Enantiopure macrocyclic ligands were synthesized from (1R,2R)‐(+)‐ and (1S,2S)‐(?)‐diphenylethylenediamine with 3,3'‐methylenebis(5‐(tert‐butyl)‐2‐hydroxybenzaldehyde) and characterized. The chirality transfer and chiral inversion from ligand to copper(II) metal centre were studied using circular dichroism spectroscopy. The enantiopure binuclear copper(II) complexes (ΔΔ and ΛΛ) were used as catalysts for asymmetric nitroaldol reaction to generate β‐nitroalcohol with 88% yield and 67% enantioselectivity. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis of Ni3V2O8@graphene oxide nanocomposite as an efficient electrode material for supercapacitor applications

Journal of Solid State Electrochemistry - In the present investigation, we have synthesized Ni3V2O8@GO composite by co-precipitation method and designed as a new anode material for supercapacitor...     

Water-Mediated Strecker Reaction: An Efficient and Environmentally Friendly Approach for the Synthesis of α-Aminonitriles via a Three-Component Condensation

The synthesis of α-aminonitriles by a direct three component Strecker reaction has been achieved in water, which is found to be an inexpensive, non-toxic and eco-friendly reaction medium for the nucleophilic addition. This protocol is effective to a wide variety of substrates with different functional groups and does not require the use any other catalyst.