A simple and convenient method for the preparation of diborane from tetrabutylammonium borohydride and benzyl chloride for application in organic synthesis

Diborane is readily generated in situ at 25 °C in toluene using the Bu₄NBH₄/PhCH₂Cl and Bu₄NBH₄/I₂ reagent systems. The reagent prepared in this way is used for the reduction of carbonyl compounds and hydroboration-oxidation of olefins to obtain the corresponding alcohols in good yields.     

A new method for the preparation of hydroperfluoroalkane from perfluoroalkyl chloride

Perfluoroalkyl chloride can be converted into hydroperfluoroalkane with zinc powder in the presence of nickel dichloride. A single electron transfer mechanism is proposed.     

A novel method for the preparation of uranium metal,oxide and carbide via electrolytic amalgamation

A solid uranium amalgam was prepared electrolytically using a two-compartment cell separated with an ion exchange membrane for the purpose of regulating pH value within a narrowly restricted region of 2 to 3. The mercury cathode was kept at −1.8 vs SCE during electrolysis. The thereby obtained amalgam containing as high as 1.9 gm U/ml Hg is easily converted into uranium metal by heating in vacuo above 1300°C. Uranium dioxide and uranium monocarbide could be easily obtained at relatively low temperature by reacting the amalgam with water vapor and methane.     

A novel method for the preparation of silver chloride nanoparticles starting from their solid powder using microemulsions

A novel method of preparing AgCl nanoparticles by mixing AgCl powder and a microemulsion consisting of dioctyldimethylammonium chloride/n-decanol/water/isooctane is introduced. This new method was discovered during the preparation of AgCl nanoparticles in single microemulsions by direct reaction with the dioctyldimethylammonium chloride surfactant counterion. The effect of the following variables on the concentration of the colloidal AgCl nanoparticles (the nanoparticle uptake) and the particle size were studied: (1) operating variables, including mixing and temperature; and (2) microemulsion variables, including surfactant and cosurfactant concentration, and water to surfactant mole ratio. Manipulating these variables provides an insight into the role of the surfactant surface layer rigidity on the phenomenon. The results were explained by the effect of these variables on reaction rates and the colloidal nanoparticle stability. Mixing had a significant effect on the nanoparticle uptake. At 300 rpm an equilibrium AgCl nanoparticle uptake was achieved in about 1 h, while without mixing only 5% of the equilibrium value was reached even after 24 h. An optimum temperature was found for which a maximum nanoparticle uptake was obtained. At higher temperatures, the nanoparticle uptake declined. The nanoparticle uptake increased linearly with the surfactant concentration, and the particle size increased as well. A monotonic decrease in the nanoparticle uptake accompanied by an increase in the particle size was observed when increasing n-decanol concentration or the water to surfactant mole ratio.     

A simple convenient method for the generation of diborane from NaBH4 and I2

Treatment of NaBH₄ with I₂ in diglyme yields diborane which can be utilized conveniently for the preparation of a borane-N,N-diethylaniline complex and other borane-Lewis base complexes.     

A novel method for the preparation of nucleoside triphosphates from activated nucleoside phosphoramidates

[reaction: see text] A novel method for the preparation of nucleoside triphosphates has been developed. The strategy employs a highly reactive pyrrolidinium phosphoramidate zwitterion intermediate that undergoes efficient coupling with tris(tetra-n-butylammonium) hydrogen pyrophosphate to generate nucleoside triphosphate.     

Adsorption of acetone and hydrogen on aluminum oxide

It was established that the adsorption of acetone at 333–365°K on the surface of aluminum oxide proceeds irreversibly and is accompanied by chemical interaction of chemisorbed molecules. A probable mechanism of the surface condensation of acetone is proposed.Translated from Teoreticheskaya i Éksperlmental'naya Khimiya, Vol. 21, No. 3, pp. 329–333, May–June, 1985.The authors would like to express gratitude to V. K. Pogorelov for his useful discussion of the results of the work.     

A novel method for the preparation of extensively dealuminated faujasites

Open structure faujasites may be dealuminated with retention of crystallinity using phosgene (or similar reactants) provided the sample has been made ultrastable in a previous procedure.

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The hydrogenation of boron monoxide to diborane and the reactions of boron and boron carbide with titanium and zirconium dioxides

Hydrogenation of boron monoxide or of systems producing it in situ, e.g. a mixture of boric oxide and carbon, above 1000° and at atmospheric pressure, yields diborane (or borine carbonyl) probably via the intermediate formation of boroxine. The reactions of boron and boron carbide with titanium and zirconium dioxides above 1100° in vacuo lead to the formation of the metal diborides and the volatile boron monoxide.     

A novel method for manufacturing of aluminum foam sandwich panels

In this study, a novel method for manufacturing aluminum foam sandwich (AFS) panels via self‐propagating high temperature synthesis (SHS) has been introduced and investigated. In this method, a powder mixture of metallic aluminum and copper oxide was placed in core–sheet interface. Sandwich panel was then heated under static pressure. During heating, SHS reaction (3CuO + 2Al = Al₂O₃ + 3Cu, ΔH < 0) occurred in the interface. The generated heat from this exothermic reaction caused sheets to join the core by melting the interface and nearby. In order to evaluate the shear strength of the interface, the shear test was applied on manufactured sandwich panels, and its results were compared with those obtained from testing the sandwich panels which were produced by diffusion bonding process. Furthermore, by the aid of energy dispersive spectrometer (EDS) and X‐ray diffraction (XRD) analyses, the formation of copper in the core–sheet interface and its diffusion into the sheets and the core were investigated. In addition, by plotting the hardness values of the panels' sheets across distance, it was found that the generated heat of the exothermic reaction caused a local melting of the panel sheets and the core. These results approved that core to sheet joining in metal foam sandwich panels took place because of the SHS reaction. Significantly, this new method could be applied as a proper and alternative method for production of AFS panels. Copyright © 2010 John Wiley & Sons, Ltd.     

A novel method for the preparation of alpha,alpha'-difluoroesters and acids using BrF3

Alkyl-, haloalkyl-, and ketoalkyl-2-ethoxycarbonyl-1,3-dithianes were easily made from the appropriate primary or secondary alkyl bromides, 1,3-dithiane, and ethyl chloroformate. They were reacted with BrF(3) to form the corresponding alpha,alpha-difluoro esters in 65-75% yield. Reaction conditions are very mild (1-2 min, 0 degrees C). The two sulfur atoms of the dithiane are essential for the reaction.     

A novel synthetic method for preparation of some folates

An improved method was developed for preparation of 5,6,7,8-tetrahydrofolic acid (THF) and calcium-5-methyltetrahydrofolate (5-MTHF-Ca) by reduction of folic acid using KBH₄ catalyzed by Pb(NO₃)₂. The yields of THF and 5-MTHF-Ca were 56.5 and 42.7 %, respectively. A convenient method for measurement of THF and 5-MTHF-Ca using liquid chromatography–mass spectrometry (LC–MS) was also established, enabling analysis of those folates within 10 min without application of gradient elution.     

A novel process for preparation of hybrid nanosized neodymium oxybromide and neodymium oxide

Russian Journal of General Chemistry - A novel process to prepare hybrid nanosized neodymium oxybromide and neodymium oxide from neodymium(III) nitrate hexahydrate has been developed. The...     

The effect of boron on zeolite-4A immobilization of iodine waste forms with a novel preparation method

Journal of Radioanalytical and Nuclear Chemistry - Immobilization of radioiodine is a significant requirement for future nuclear fuel development. This research mainly focuses on the production of...     

A novel chelating acid-assisted thermolysis procedure for preparation of tin oxide nanoparticles

Pure tin dioxide (SnO₂) nanoparticles were synthesized via thermolysis of tin phthalate and tin oxalate in the presence of oleic acid (OA) as solvent. Oleic acid (OA) was employed as an organic solvent, which can be applied to control particle growth and to stabilize the particles. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. The orthorhombic phase SnO₂ nanoparticles with average size about 12 nm were synthesized through thermolysis of tin phthalate in the presence of oleic acid.     

Nanoscale lanthanum oxide catalysts for self-condensation of acetone: preparation via self-assembly on anodic aluminum oxide,structure, and properties

A novel structured La₂O₃/AAO solid base catalyst was prepared by supporting lanthanum oxide (La₂O₃) on the surface of anodic aluminum oxide (AAO) under hydrothermal conditions. Catalytic activity of the catalyst was tested using self-condensation of acetone to diacetone alcohol as a probe reaction. The conversion of acetone reached 4.14% with the diacetone alcohol selectivity of 98%. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), thermogravimetric analysis (TGA), N₂ adsorption-desorption (BET), and temperature programmed desorption (CO₂-TPD). XRD patterns and SEM images indicated that La₂O₃ nanoscale particles with high crystallinity were uniformly distributed over the AAO surface. The results of CO₂-TPD showed that the calcination temperature led to the formation of medium-strength basic sites, strong basic sites, and to an increase of the basic strength. The strong basic sites and large basic strength are an important factor that influences the catalytic activity in the self-condensation of acetone to diacetone alcohol.     

A specific method for the preparation of many transition metal and actinide oxide tetrafluorides

A general method for the preparation of many transition metal and actinide oxide tetrafluorides by oxygen-fluorine exchange of their respective hexafluorides using boric oxides is described. This simple procedure affords the preparation of MoOF₄, WOF₄, ReOF₄, OsOF₄ and UOF₄ in high yield while reaction of boric oxide with IrF₆ and RuF₆ leads to the preparation of lower fluorides of these elements. The preparation of oxide tetrafluorides by reaction of their oxide tetrachlorides with anhydrous HF has also been investigated, as well as a study of some halogen-exchange reactions of the oxide tetrafluorides.     

A safe, convenient and efficient method for the preparation of heterocyclic N-oxides using urea·hydrogen peroxide

A novel, convenient, and high-yielding method has been developed for the preparation of heterocyclic N-oxides. The reaction uses the urea·hydrogen peroxide addition complex as a peroxide source for the in situ generation of trifluoroperacetic acid. The advantages of this method are easy handling of a stable, solid oxidant; high yields and simple removal of excess reagents and by-products.     

A novel sacrificial interlayer-based method for the preparation of silicon carbide membranes

A novel method is presented based on the use of sacrificial interlayers for the preparation of nanoporous silicon carbide membranes. It involves periodic and alternate coatings of polystyrene sacrificial interlayers and silicon carbide pre-ceramic layers on the top of slip-casted tubular silicon carbide supports. Membranes prepared by this technique exhibit single gas ideal separation factors of helium and hydrogen over argon in the ranges 176–465 and 101–258, respectively, with permeances that are typically two to three times higher than those of silicon carbide membranes prepared previously by the more conventional techniques. Mixed-gas experiments with the same membranes indicate separation factors as high as 117 for an equimolar H₂/CH₄ mixture. We speculate that the improved membrane characteristics are due to the sacrificial interlayers filling the pores in the underlying structure and preventing their blockage by the pre-ceramic polymer. The new method has good promise for application to the preparation of a variety of other inorganic microporous membranes.