Showing papers on "Halide published in 1997"

Hydrogen-transfer hydrodehalogenation of aromatic halides with alcohols in the presence of noble metal catalysts

Abstract: Catalytic hydrodehalogenation of aromatic halides was carried out in an alcohol solution containing base compounds in the presence of carbon-supported noble metal catalysts. It was found that dechlorination of 1,2,4-trichlorobenzene to benzene effectively occurred in a 2-propanol solution of a base compound such as NaOH or KOH in the presence of Rh/C or Pd/C at temperatures below 65°C. When deuorium-labeled 2-propanol, CD3CD(OD)CD3, was used as a solvent, 1,2,4-trichlorobenzene was dechlorinated to give benzene containing D atoms with high yield, indicating that the hydrodechlorination reaction includes hydrogen-transfer from 2-propanol to chlorobenzenes. Iodo-, bromo- and fluoro-benzenes were also readily dehalogenated in the catalytic system.

Synthesis and properties of ambient temperature molten salts based on the quaternary ammonium ion

Abstract: The synthesis of 16 tetraalkyl ammonium bis(trifluoromethane sulfonyl) imide salts, Open image in new window are reported in this paper. Trends in properties of these salts are discussed. The symmetrical tetraalkyl ammonium salts with the bis(trifluoromethyl sulfonyl) imide anion exhibited a lower melting point than that of corresponding ammonium halides. The salts with low symmetry ammonium cations were found to be of generally lower melting point, and many were stable liquids at room temperature. Several of these did not crystallize during cooling below room temperature and exhibited glass transition temperatures in the region of −60 °C∼−80 °C. A comparison of properties between the ammonium imide salts and corresponding trifluoromethane sulfonates is also presented.

Adsorption of halide anions at the Pt(111)-solution interfacestudied by in situ surface x-ray scattering

Abstract: In this paper we present x-ray scattering results of iodide, bromide, and chloride adsorption onto the Pt(111) surface in solution. Iodide forms two commensurate adlayer structures, a ($\sqrt{7}$\ifmmode\times\else\texttimes\fi{}$\sqrt{7}$)R19.1\ifmmode^\circ\else\textdegree\fi{} phase and a hexagonal (3\ifmmode\times\else\texttimes\fi{}3) phase, which coexist on the Pt surface. Formation of the (3\ifmmode\times\else\texttimes\fi{}3) phase appears to be kinetically limited, whereas the $\sqrt{7}$ phase shows a hysteretic effect as a function of the electrode potential, associated with an order-disorder transition. Bromide forms a series of high-order commensurate structures on Pt(111) that are poorly ordered unless the size of the unit cell is small. No ordered structures for chloride adsorption are observed and specular x-ray reflectivity results suggest that the chloride coverage at low potential is too small to form a close-packed monolayer on the surface. The differences between the structures formed by the adsorbed anions, and the differences between results for Pt(111) and Au(111), are discussed in terms of the strength of the metal-halide interaction.

High temperature epoxy resin compositions, additives and methods

Abstract: Improved high temperature epoxy resin compositions, additives and methods are provided. A hardenable epoxy resin composition of the present invention is comprised of an epoxy resin, an aromatic diluent, a hardening agent and a hardening retarder for delaying the hardening of the epoxy composition at high temperatures comprised of a liquid which is soluble in the epoxy resin composition having a halide salt dissolved therein.

New diazomethane compound

Abstract: PROBLEM TO BE SOLVED: To obtain the new subject compound useful as an acid generating agent for a chemically amplifying type resist good in resolution, pattern form and rate of a remaining membrane. SOLUTION: This diazomethane compound is the one of formula I [each R is H or forms dimethylmethylene group by binding two Rs in the same ring; R and R are each a lower alkyl; (n) is 0 or 1], e.g. bis[2-(1 -ethoxyethyloxy) cyclohexysulfonyl] diazomethane. The compound of formula I is obtained by reacting a thiol compound with a methylene halide in a solvent such as ethanol in the presence of a hydrogen halide scavenger such as an alkali hydroxide to provide a compound of formula II, oxidizing the obtained compound of formula II with an oxidizing agent such as hydrogen peroxide to provide a bissulfonylmethane body, diazotizing the bissulfonylmethane body to provide a bissulfonyldiazomethane body, reacting the bissulfonyldiazomethane body with an alkoxyalkene by using a catalyst such as pyridinium p-toluenesulfonate, and separating and purifying the product.

Highly permeable composite reverse osmosis membrane and a reverse osmosis membrane module using the same

Abstract: The present invention provides a composite reverse osmosis membrane and a reverse osmosis membrane module using the same, having a high salt rejection, high water permeability, and a high rejection of organic substances such as isopropyl alcohol, which can be used to remove organic substances as well as ionic substances with suitable efficiency and economy. The highly permeable composite reverse osmosis membrane of the invention can be produced by adding alcohols or ethers or the like having a solubility parameter of 8-14 (cal/cm3)1/2 to the solution containing at least one compound selected from the group consisting of a compound having two or more reactive amino groups and a polyfunctional acid halide having two or more reactive acid halide groups which is used when conducting the polycondensation of a compound having two or more reactive amino groups and a polyfunctional acid halide having two or more reactive acid halide groups on a microporous support.

New method for estimating the degree of ionization and counterion selectivity of cetyltrimethylammonium halide micelles: Chemical trapping of free counterions by a water soluble arenediazonium ion

Abstract: Products from spontaneous reaction of a short-chain, water soluble arenediazonium salt, 2,4,6-trimethylbenzenediazonium tetrafluoroborate (1-ArN2BF4), in aqueous micellar solutions of cetyltrimethylammonium halides ((CTA)X (X = Cl, Br)) are used to estimate the degree of ionization, α, and the ion exchange constant, KBr/Cl. The arenediazonium ion (1-ArN2+) reacts by rate-determining loss of N2 to give an aryl cation that traps available nucleophiles, i.e. H2O, Cl-, and Br-, to give stable phenol (1-ArOH) and halobenzene products (1-ArCl and 1-ArBr), respectively. Product yields are determined by HPLC from calibration curves obtained from independently prepared standards. Reproducible yields are obtained at very low halide ion concentrations, on the order of millimolar, well within the range needed to detect the “free counterions” in the aqueous intermicellar pseudophase. The basic assumption of the method is that 1-ArN2+ remains in the aqueous pseudophase at all (CTA)X and NaX concentrations. Trends in th...

Ceramic metal halide discharge lamp with NaI/CeI3 filling

Abstract: Metal halide lamp with ceramic discharge vessel having electrodes with spacing EA, internal diameter Di, and EA/Di>5. Ionizable filling comprises NaI and CeI 3 , and a coldest spot temperature of 1100-1500 K is achieved.

Diffusive transport properties in monovalent and divalent metal-ion halide melts: A computer simulation study

Abstract: Self- and cross-velocity correlation functions and related transport coefficients of molten salts are studied by molecular-dynamics simulation. Six representative systems are considered, i.e., NaCl and KCl alkali halides, CuCl and CuBr noble-metal halides, and ${\mathrm{SrCl}}_{2}$ and ${\mathrm{ZnCl}}_{2}$ divalent metal-ion halides. Computer simulation results are compared with experimental self-diffusion coefficients and electrical conductivities. Special attention is paid to dynamic cross correlations and their dependence on the Coulomb interactions as well as on the size and mass differences between anions and cations.

Vapor phase oxidation of propylene to propylene oxide

Abstract: Propylene is converted to propylene oxide in a vapor phase oxidation process employing a silver catalyst supported on an alkaline earth metal carbonate and containing both a potassium salt such as potassium nitrate and a molybdenum promoter. The potassium salt and the molybdenum promoter may be simultaneously supplied by the use of a potassium salt of a molybdenum oxyanion. The efficiency of the process is greatly enhanced through the simultaneous inclusion of carbon dioxide and an organic halide in the feedstream. The feedstream need not contain a nitrogen oxide species such as NO to attain high propylene oxide selectivity.

Liquid phase catalytic fluorination of hydrochlorocarbon and hydrochlorofluorocarbon

Abstract: A process for the catalytic fluorination of hydrochlorocarbons and hydrochlorofluorocarbons in the liquid phase. The process is useful for fluorinating hydrochloropropanes, hydrochlorofluoropropanes, hydrochloropropenes and hydrochlorofluoropropenes and most particularly useful for fluorinating 1,1,1,3,3-pentachloropropane to 1,1,1,3,3-pentafloropropane. Suitable catalysts include (i) a pentavalent molybdenum halide; (ii) a tetravalent tin halide; (iii) a tetravalent titanium halide; (iv) a mixture of a pentavalent tantalum halide with a tetravalent tin halide; (v) a mixture of a pentavalent tantalum halide with a tetravalent titanium halide; (vi) a mixture of a pentavalent niobium halide with a tetravalent tin halide; (vii) a mixture of a pentavalent niobium halide with a tetravalent titanium halide; (viii) a mixture of a pentavalent antimony halide with a tetravalent tin halide; (ix) a mixture of a pentavalent antimony halide with a tetravalent titanium halide; (x) a mixture of a pentavalent molybdenum halide with a tetravalent tin halide; (xi) a mixture of a pentavalent molybdenum halide with a tetravalent titanium halide and (xii) a mixture of a pentavalent antimony halide with a trivalent antimony halide. Products of this process are useful in a variety of applications including solvents, blowing agents, and refrigerants.

Hydroxy-functionalized poly(amino ether) salts

Abstract: Poly(hydroxyaminoether) ammonium salts are prepared by contacting a poly(hydroxy amino ether) with a protonic acid or an alkyl halide in an amount and under reaction conditions sufficient to form a poly(hydroxy amino ether) ammonium salt having an oxygen transmission rate of less than about 0.5 cm 3 -mil/100 in 2 -atm(O 2 )-day.

Linear alxylbenzene formation using low temperature ionic liquid

Abstract: A low temperature molten ionic liquid composition comprising a mixture of a metal halide and an alkyl-containing amine hydrohalide salt can be used in linear alkylbenzene formation. The metal halide is a covalently bonded metal halide which can contain a metal selected from the group comprised of aluminum, gallium, iron, copper, zinc, and indium, and is most preferably aluminum trichloride. The alkyl-containing amine hydrohalide salt may contain up to three alkyl groups, which are preferably lower alkyl, such as methyl and ethyl.

New Access to Cross-Coupling Reaction between Arylsilanes or Heteroarylsilanes and Aryl Halides Mediated by a Copper(I) Salt

Abstract: Copper(I) salt can be used as a promoter for the cross-coupling reactions between aryl- or heteroarylsilanes and aryl halides without a fluoride ion. Under these mild conditions, even a substrate containing a fluoride ion-sensitive silyloxyl group was employed directly.

Synthesis of Transition-Metal Nitrides from Nanoscale Metal Particles Prepared by Homogeneous Reduction of Metal Halides with an Alkalide

Abstract: Transition-metal nitrides have been synthesized by heating nanoscale metal particles under flowing N2(g) or NH3(g). In some cases reaction temperatures are significantly lower than those required by conventional heating procedures. Nanoscale metal particles of Mo, Nb, Ta, Fe−Mo, Fe−Nb, and Cu−Nb were prepared by reduction of the respective metal chloride or mixture of chlorides with the sodide, [K+(15-crown-5)2]Na-, in dimethyl ether solution. The previously characterized nitrides that were prepared (with synthesis conditions indicated) include γ-Mo2N (800 °C, N2) and Mo2N (720 °C, N2), Ta3N5 (650 °C, NH3), Fe3Mo3N (>650 °C, N2), and a mixture of niobium nitride phases (800 °C, N2). A previously unreported phase has been found in the Ba−Nb−N system.

Compounds and catalysts for the polymerization of olefins

Abstract: The present invention relates to components of catalysts for the polymerization of olefins comprising a metallocene compound and a magnesium halide which have particular values of porosity and surface area. Group 4 and vanadium metallocenes are useful metallocenes and the components typically include an electron donor such as an ether, ester or ketone. In particular the components of the invention have surface area (BET) greater than about 50 m 2 /g, porosity (BET) greater than about 0.15 cm 3 /g and porosity (Hg) greater than 0.3 cm 3 /g, with the proviso that when the surface area is less than about 150 m 2 g, the porosity (Hg) is less than about 1.5 cm 3 /g. The magnesium halide is complexed by an ether, ester, or ketone electro donor. The components of the invention are particularly suitable for the preparation of catalysts for the gas-phase polymerization of α-olefins.

Cs8ga11, a new isolated cluster in a binary gallium compound. a family of valence analogues a8tr11x : a = cs, rb; tr = ga, in, tl; x = cl, br, i

Abstract: Fusion of the elements, and alkali-metal halide when appropriate, in stoichiometric amounts in Ta containers followed by slow cooling results in high yields of the title compounds. X-ray structures...

Electrochemical Quartz Crystal Microbalance Study of Halide Adsorption and Concomitant Change of Surface Excess of Water on Highly Ordered Au(111)

Abstract: An electrochemical quartz crystal microbalance (EQCM) has been applied to a quantitative adsorption study of halide anions such as I-, Br-, Cl-, and F-, as well as the change in the surface excess of water directly related to the halide adsorption on a highly ordered Au(111) electrode. It was found that the strength of halide adsorption decreases in the sequence I- > Br- > Cl- > F-. The potential dependent surface coverage of halide anions and the concomitant change of surface excess of water were determined. The maximum coverages of I-, Br-, and Cl- on Au(111) before the onset of the halide oxidation were 0.43, 0.56, and 0.53, respectively, which are in good agreement with reported values determined by other methods. The water molecules on the surface were found to be expelled by close-packed adsorption of halides. The adsorption behavior of halide anions has been discussed extensively. This work has demonstrated that the combination of EQCM with single crystal electrodes can yield a wealth of informatio...

Halftone phase shift mask, blank for the same, and methods of manufacturing these

Abstract: A quartz glass substrate is placed in a DC or RF sputtering apparatus containing argon gas or oxygen gas. A zirconium compound target is reactively sputtered to form at least one halftone film made of a zirconium compound target on the substrate, thereby forming a blank for a halftone phase shift mask. The refractive index, the extinction coefficient, and the film thickness of the halftone film are so determined that the transmittance and the reflectance to exposure light are 2 to 15% and 30% or less, respectively, and the transmittance to inspection light is 30% or less. Examples of the zirconium compound are zirconium oxide, zirconium nitride, zirconium oxynitride, zirconium oxycarbide, zirconium carbonitride, zirconium halide, zirconium halide oxide, zirconium halide nitride, zirconium oxide silicide, zirconium nitride silicide, zirconium oxynitride silicide, zirconium oxycarbide silicide, zirconium carbonitride silicide, zirconium halide silicide, zirconium halide oxide silicide, and zirconium halide nitride silicide.