Showing papers on "Halide published in 1982"

Computer Simulation of Solids

Abstract: Theory of simulation methods for lattice and defect energy calculations in crystals.- Theory and calculation of defect entropies.- Characteristic volumes of point defects in tonic crystals.- Free energy calculations for crystals.- Molecular dynamics simulations of crystalline ionic materials.- Ab initio cluster calculations for defects in the solid state.- Computational methods for the electronic structure of defects in insulators.- Interatomic potentials in solids.- Potentials in metals.- Interionic potentials in ionic solids.- Interatomic potentials in covalent and semi-covalent solids.- Defect calculations for ionic materials.- Point defect calculations in metals.- Defect calculations in semiconductors.- Computer modelling of complex and massively disordered crystalline solids.- Aspects of the chemistry of phyllosilicates and intercalation in vermiculites.- Aggregation and precipitation in alkali halides.- Computer simulation of fast ton conductors.- Computer simulation of ionic crystal surfaces.- Long range order in non-stoichiometric oxides.

Supported transition metal composition

Abstract: A supported transition metal composition is obtained by suspending a support material in an inert liquid medium, spraying the suspension, collecting a solid material and contacting the sprayed solid with a transition metal compound. The support material may be a metal halide such as magnesium chloride or an inorganic oxide such as silica or alumina. In addition to being contacted with the transition metal compound, the support material may be contacted either before or after the spraying step with other reagents such as organo metallic compounds, halogen compounds, or Lewis Base compounds. The product obtained after contacting with the transition metal compound may be used as a component of a polymerization catalyst system to polymerize an unsaturated monomer such as ethylene or propylene.

Photoelectrochemistry with Colloidal Semiconductors; Laser Studies of Halide Oxidation in Colloidal Dispersions of TiO2 and α-Fe2O3

Abstract: Aqueous sols of TiO2 (anatase, particle radius 25 A) were excited with (347.1 nm)-laser light and the reaction of valence-band holes with halide ions (X = I−, Br−, Cl−) was investigated. Hole transfer takes place within the duration of the (10 ns)-laser pulse and results in the formation of anion radicals according to the sequence: The quantum yield of X increases in the order Cl < Br < I, attaining 0.8 for I at pH 1. It is affected by pH, halide concentration and the presence of a protective agent for the sol. RuO2 deposited onto TiO2 enhances markedly Cl and Br -formation, but has no effect on the yield of I. Laser-photolysis investigation of halide oxidation were also carried out with colloidal Fe2O3 (particle radius 600 A). For I2−formation, the quantum yield exceeds 0.9 indicating almost quantitative hole scavenging by iodide.

Study of the electronic structure of twelve alkali halide crystals

Abstract: In this manuscript we use nonrelativistic self-consistent Hartree-Fock theory to compute the electronic structure of twelve alkali halides. Only compounds containing Cs or I are excluded because the author believes that relativistic effects should be included for such compounds. Correlation effects are included by our previously developed methods. The calculations are performed to compare to photoemission-type data. Extensive comparisons to such data are made. In this calculation a new version of the local-orbitals theory is used, and the bands are computed with the use of a modern development of the mixed-basis method.

Supported catalyst for polymerization of olefins

Abstract: An unmilled catalytic component for polymerizing olefins with high activity to yield polymers with high stereoregularity and a narrow particle size distribution with a low weight percentage of small particles comprises a solid, unmilled support containing magnesium-halogen bonds, a transition metal halide of a metal selected from Groups IVB and VB of the periodic table, and electron donors. This catalytic component is obtained by steps comprising: (a) contacting a Mg(OR)2 and/or Mn(OR)2 compound with a Ti(OR)4 compound to comprise a liquid, where R is a hydrocarbyl or halogenated hydrocarbyl moiety containing 1 to 20 carbon atoms or a halogen, (b) reacting the liquid with a fluid comprising a halogenating agent and treatment with an electron donor to form a treated solid, and (c) post-treating the solid with a transition metal halide.

Palladium-catalyzed cross-coupling reactions between allyl, vinyl or aryl halide and perfluoroalkyl iodide with zinc and ultrasonic irradiation

Abstract: The reactions of perfluoroalkyl iodides with allyl, vinyl or aryl halides with ultrasonically dispersed zinc in the presence of palladium catalyst proceeded smoothly to give the corresponding allyl...

Silver chloride emulsions of modified crystal habit and processes for their preparation

Abstract: Radiation-sensitive photographic emulsions are disclosed comprised of a dispersing medium and silver halide grains the halide content of which is at least 50 mole percent chloride, based on silver. The silver halide grains include tabular grains having a thickness of less than 0.5 micron, a diameter of at least 0.6 micron, and an average aspect ratio greater than 8:1 which account for at least 50 percent of the total projected area of the silver halide grains. The tabular grains have two opposed substantially parallel major crystal faces lying in {111} crystal planes and exhibiting at least one of the following features: (1) at least one peripheral edge lying parallel to a crystallographic vector lying in the plane of one of the major faces and (2) bromide and/or iodide incorporated in a central grain region. The tabular grains are formed in the presence of an aminoazaindene and a peptizer having a thioether linkage.

Process for the preparation of catalyst component for the polymerization of olefins

Abstract: A process for the preparation of the former catalyst component of a catalyst for the polymerization of olefins composed of a titanium-based catalyst component and an organo aluminium compound is disclosed, which process comprises suspending (a) a fatty acid salt of magnesium and (b) dialkoxymagnesium into (c) a liquid halogenated hydrocarbon to form a first suspension, and adding said first suspension to (d) a titanium halide of the general formula: TiX4, wherein X represents a halogen atom, to be contacted for reaction to form a first reaction mixture, (e) an electron donor compound being present in at least one of the first suspension, the titanium halide and the first reaction mixture; or suspending the dialkoxymagnesium into the liquid halogenated hydrocarbon to form a second suspension, and adding said second suspension to a mixture of the titanium halide and the fatty acid salt of magnesium to be contacted for reaction to form a second reaction mixture, the electron donor compound being present in at least one of the second suspension, the mixture of the titanium halide and the fatty acid salt of magnesium, and the second reaction mixture. In the polymerization of olefins by use of the former catalyst component, both the amount of catalyst residues in the produced polymer and halogen content therein are greatly reduced with high polymerization activity per unit weight of the former catalyst component and with high yield of stereoregular polymer.

Chemisorption of Organic Compounds on a Clean Aluminum Surface Prepared by Cutting Under High Vacuum

Abstract: The chemisorption of organic compounds as model compounds of lubrication additives has been studied at room temperature on a clean aluminum surface which was prepared by cutting under high-vacuum conditions. Hydrocarbons such as n-hexane, butene, and cyclohexene did not adsorb, but alkyl halides, organic acid, and alcohols adsorbed on the clean aluminum surface. The adsorption activity was monitored with a quadrupole mass spectrometer and was affected by cutting conditions. The rate of adsorption was proportional to the cutting speed. The chemisorption took place not only during but also after the cutting. From the kinetic considerations, it has been found that the activity was mainly due to the newly formed aluminum surface. The reactivity sequence of the organic compounds was as follows; alkyl halides > alcohols > organic acid >> alkane, alkene.

Inhibition of scale deposition from steam generation fluids

Abstract: A method for treating a hot water-containing fluid stream passing through a conduit, under conditions of temperature and pressure whereupon at least a portion of the water flashes to steam, to inhibit the formation of scale deposited on the conduit and/or dissolve any such scale already formed, and to inhibit corrosion of the conduit wherein there is added to the fluid stream an effective amount of a solution of a water-soluble compound which provides a nitrogen-containing cation capable of flashing to become a gas at high temperatures selected from the group consisting of ammonium halides, ammonium salts of inorganic acids, ammonium salts of organic acids, ammonium salts of alpha hydroxy organic acids, quaternary ammonium halides, quaternary ammonium salts of inorganic acids, quaternary ammonium salts of organic acids, amine salts of inorganic acids, amine salts of organic acids and amides. Optionally the solution or dispersion also contains a water-soluble or dispersible polymer and/or a buffering agent.

Supported catalysts for the polymerization of ethylene

Abstract: "Improvements in supported catalysts for the polymeriza-tion of ethylene". A process for the preparation of a catalyst which is highly active in the polymerization of gaseous ethylene is described the process comprising the steps of spray drying an ethanolic solution of MgCl2 to obtain MgCl2 particles of from 3 to 100 microns in size and with a residual alcoholic OH-groups content of from 1.5% to 20% by wt., the MgCl2 in said particles having an X-ray spectrum with a maximum peak at 10.8 angstrom, reacting said particles with a titanium halide in liquid or vapor phase and mixing the obtained reaction product with an alkylaluminium or an alkylaluminium halide in such amount to obtain an atomic ratio Al:Ti of from 100:1 to 5,000:1.

Silver chlorobromide emulsions and processes for their preparation

Abstract: Tabular grain silver halide emulsions are disclosed containing chloride and bromide in at least annular grain regions. The tabular grains having a thickness of less than 0.5 micron, preferably less than 0.3 micron, a diameter of at least 0.6 micron, and an average aspect ratio of at least 5:1, account for at least 35 percent of the total projected area of the total silver halide grain population. The average molar ratio of chloride to bromide in at least the annular grain regions ranges up to 2:3. The tabular grains containing chloride and bromide in at least annular grain regions are formed by maintaining a molar ratio of chloride and bromide ions of from 1.6:1 to 258:1 and the total concentration of halide ions in the reaction vessel in the range of from 0.10 to 0.90 N during introduction of silver, chloride, and bromide salts into a reaction vessel, thereby favoring the coprecipitation of chloride and bromide in a tabular crystal habit.

Disposal process for halogenated organic material

Abstract: A method for disposing of a halogenated organic material includes the steps of partially oxidizing the halogenated organic material, a hydrocarbonaceous material, and a nitrogen compound with a free-oxygen containing gas and optionally with a temperature moderator in a synthesis gas generator under partial oxidation conditions. The partial oxidation produces a synthesis gas containing, among others, hydrogen halide and ammonia. The synthesis gas is then contacted with a quench medium which dissolves the hydrogen halide into the quench medium. The hydrogen halide and quench medium can be disposed of by the addition of a base to form a readily disposed metal salt of the halide.

Synthesis of high polymers from disubstituted acetylenes using halides of niobium (V) and tantalum (V) as catalysts

Abstract: When oct-3-yne and 1-phenylprop -1-yne are polymerised by halides of NbV and TaV white soluble polymers are obtained whose weight-average molecular weights exceed one million.

Method of inhibiting silica dissolution during injection of steam into a reservoir

Abstract: A method for inhibiting the dissolution of silica from the matrix around a well during injection of steam into the matrix by adding to the feedwater used to generate the steam or the steam itself an inhibitor comprising an ammonium or substituted ammonium compound selected from the group consisting of ammonium halides, ammonium salts of inorganic acids, ammonium salts of carboxylic acids, quaternary ammonium halides, and amine or substituted amine hydrochlorides.

Production of aromatic polyketones

Abstract: Production of an aromatic polyketone by reacting in the presence of a fluoroalkane sulphonic acid the reactants selected from: (a) a mixture of (i) at least one aromatic diacyl halide WOC--Ar--COW where --Ar'-- is a divalent aromatic radical, W is halogen and COW is an aromatically bound acyl halide group, which diacyl halide is polymerizable with the at least one aromatic compound of (ii), and (ii) at least one aromatic compound H--Ar'--H where --Ar'-- is a divalent aromatic radical and H is an aromatically bound hydrogen atom, which compound is polymerizable with the at least one diacyl halide of (i); (b) at least one aromatic monoacyl halide H--Ar"--COW where --Ar"-- is a divalent aromatic radical and H, W, and COW are as defined in (a), which monoacyl halide is self-polymerizable; and (c) a combination of (a) and (b).

Platinum-styrene complexes as catalysts for hydrosilation reactions and a process for preparing the same

Abstract: Platinum-styrene complexes are prepared by reacting a platinum halide with styrene or substituted styrenes in the presence of a basic material for a sufficient amount of time to form a complex having more than one and less than four gram atoms of halogen per gram atom of platinum. These platinum-styrene complexes may be used to promote the addition of organosilicon compounds having at least one ≡SiH group per molecule to a compound containing aliphatic unsaturation.

Catalytic component for polymerization of α-olefin and method for homo- or co-polymerization of α-olefin

Abstract: A Ziegler type supported catalytic component for polymerization of an α-olefin is prepared by allowing an organo-magnesium compound expressed by a generic formula of R'MgX' (wherein R' represents a hydrocarbon group having 1 to 20 carbon atoms and X' either a halogen atom chosen out of chlorine, bromine and iodine or a hydrocarbon group having 1 to 20 carbon atoms) to react wtih carbon tetrahalide in the presence of an electron donor compound to obtain a solid product through a solid-liquid separation process; by heat treating the separated solid product with a carbon halide; by treating the heat treated solid product with phenols at 90° to 180° C.; and by treating this phenol treated product further with a halogenated titanium compound. Homo- or co-polymerization of an α-olefin is carried out in the presence or a catalyst composition consisting of the above catalytic component and an organo-aluminum compound. With this catalytic component, stereospecific polymerization of an α-olefin can be stably carried out at high temperature.

Infrared polarizing glasses

Abstract: The instant invention is directed to the preparation of glass articles exhibiting excellent polarization in the infrared portion of the spectrum from glasses characterized as containing silver halide particles therein selected from the group of AgCl, AgBr, AgI. The inventive method comprises four general steps: (a) a batch for a glass containing silver and at least one halide selected from the group of chloride, bromide, and iodide is melted and the melt shaped into a glass body of a desired geometry; (b) the glass body is subjected to a heat treatment at least above the strain point but not in excess of 50° C. above the softening point of the glass for a period of time adequate to cause the generation of AgCl and/or AgBr and/or AgI particles therein, said particles ranging in size between 200-5000 Å; (c) the glass body is elongated under stress at temperatures above the annealing point, but below that where said glass exhibits a viscosity of about 10 8 poises, such that the particles are elongated to an aspect ratio of at least 5:1; and (d) the elongated glass body is exposed to a reducing environment at temperatures between 250° C. and about 25° above the annealing point of the glass to reduce the silver halide particles in the glass to metallic silver which is deposited in and/or upon the elongated particles.

4'-Halo-substituted sucrose derivatives

Abstract: Compounds of the general formula (I) ##STR1## (wherein X represents a halogen atom; R 1 and R 2 respectively represent a combination selected from the group consisting of: a hydroxy group and a hydrogen atom; a halogen atom and a hydrogen atom; and a hydrogen atom and a halogen atom; and R 3 and R 4 , which may be the same or different, each represent a substituent selected from the group consisting of a halogen atom and a hydroxy group; at least one of R 1 , R 2 and R 3 representing a halogen atom) are potent sweeteners obtainable by opening a corresponding 3',4'-lyxoepoxide with a source of halide ions.

Catalyst for polymerization of olefins

Abstract: A catalyst comprising (A) a solid catalyst component obtained by reacting a titanium compound having a hydrocarbyloxy group with an organoaluminum compound in the presence of an ether to give a liquid material or to give a solid titanium component (a) which is solubilized by addition of a tetravalent titanium halide with or without an ether without separation or after separation from the reaction mixture, and heat treating the liquid material at a temperature of 70° to 180° C. with or without addition of a tetravalent titanium halide, and (B) an organoaluminum compound is effective for polymerization or copolymerization of olefins with high stereoregularity and has high polymerization activity.

The Reaction of Bis(dimethylglyoximato)(pyridine)cobalt(I), Cobaloxime(I), with 2-(Allyloxy)ethyl Halides and the Photolysis of the Resulting Organo-cobaloximes

Abstract: The reactions of 2-(allyloxy)ethyl halides with cobaloxime(I) gave (tetrahydro-3-furanyl)methylcobaloximes via an electron transfer from cobaloxime(I) to the halides to give radical anions. The rupture of a halide ion to give an organic radical and the ring closure to give a (tetrahydro-3-furanyl)methyl radical are followed by the radical coupling between the organic radical and the cobaloxime(II). The structures of the organo-cobaloximes were determined by the analyses of the photolysis products under aerobic or anaerobic conditions.