Showing papers on "Halogen published in 1983"

A simple, controllable source for dosing molecular halogens in UHV

Abstract: An electrochemical source for the reproducible generation and dosing of halogens in UHV systems is described. This approach minimizes corrosion damage to vacuum hardware and lends itself to the study of both submonolayer and multilayer halogen adsorption. The corrosive action of halogens on ultrahigh vacuum components has necessitated the development of molecular halogen beam sources, which allow in situ generation and dosing of fluorine, chlorine, bromine, and iodine, with a negligible increase in vacuum chamber background pressure. This communication describes the chlorine and bromine sources developed and routinely used in our laboratory. Iodine dosing may be accomplished using a source of similar design. Fluorine, however, because of its highly reactive nature, requires a somewhat different design of source, such as that recently described in detail by Bechtold.1

Use of substituted 2-(2'-hydroxyaryl)-2h-benzotriazolesulfonates as photostabilising agents for natural and synthetic fibres

Abstract: A method for protecting synthetic and natural fibres against phototendering. The method comprises treating the fibres with a substituted benzotriazolesulfonate of formula (A) wherein (I) R1 is hydrogen or halogen, R2 is hydrogen or alkyl, R3 is hydrogen or hydroxy, R4 is -SO3X where X is hydrogen or an alkali metal, and R5 is hydrogen, with the proviso that R2 is not methyl when R1 and R3 are hydrogen; or (II) R1, R3 and R4 are hydrogen, R2 is -SO3X where X is hydrogen or an alkali metal, and R5 is -OR6 where R6 is hydrogen or alkyl; or (III) R1 is hydrogen or halogen, R2 is -SO3X where X is hydrogen or an alkali metal, R3 and R5 are hydrogen, and R4 is hydrogen, alkyl or benzyl; or (IV) R1 is -SO3X where X is hydrogen or an alkali metal, R2 is alkyl, R3 and R5 are hydrogen, and R4 is hydrogen or alkyl; under acidic conditions. The method is particularly suitable for treating wool, silk and nylon fibres, including blends thereof.

Fluorine induced chemiluminescence detector for reduced sulfur compounds

Abstract: A new gas chromatography detector with selectivity for reduced sulfur compounds is described. The detector monitors chemiluminescence resulting from the reaction of the GC effluent with molecular fluorine at reduced pressures. The reaction of sulfur compounds with fluorine produces vibrationally excited HF whose emission is detected with a red-sensitive photomultiplier tube. Detection limits in the range of 24-260 pg of analyte were obtained for a variety of sulfides, disulfides, and mercaptans. The detector has a linear response to sulfur compounds over at least 3 orders of magnitude and a selectivity over normal hydrocarbons of greater than 10/sup 7/. Selectivities over a variety of other classes of organic compounds also are presented. 25 references, 6 figures, 3 tables.

Kinetics of the reaction of chlorine atoms with vinyl bromide and its use for measuring chlorine-atom concentrations

Abstract: The reaction of chlorine atoms with vinyl bromide, Cl + C/sub 2/H/sub 3/Br ..-->.. C/sub 2/H/sub 3/Cl + Br, has been tested as a titration reaction for chlorine atoms in gas-phase fast-flow reactors using both continuous and pulsed atom sources. The vinyl chloride produced by this reaction was determined by using photoionization mass spectrometry and was found to be an accurate measure of the in situ chlorine-atom concentration down to 5 x 10/sup 10/ atoms cm/sup -3/. The reaction is rapid and stoichiometric and involves the use of easily handled substances. It is particularly well suited for use with photoionization mass spectrometer detectors because of the low ionization potentials and high photoionization cross sections of both vinyl bromide and vinyl chloride. The rate constant of this reaction was measured at 298/sup 0/K and determined to be 1.43 (+-0.29) x 10/sup -10/ cm/sup 3/ molecule/sup -1/ s/sup -1/.

Selective vibrational excitation of the ethylene--fluorine reaction in a nitrogen matrix. II

Abstract: The product branching between 1,2‐difluoroethane and vinyl fluoride (plus HF) of the selective vibrationally stimulated reaction of molecular fluorine with C2H4 has been studied in a nitrogen matrix at 12 K and found to be the same for five different vibrational transitions of C2H4 between 1896 and 4209 cm−1. The HF/DF branching ratio of the reaction of F2 with CH2CD2, trans‐CHDCHD, and cis‐CHDCHD was determined to be 1.1, independent of precursor C2H2D2 isomer and particular mode which excited the reaction. These results, as well as the analysis of the mixtures of partially deuterated vinyl fluoride molecules produced by each C2H2D2 isomer indicate that the product branching occurs by αβ elimination of HF(DF) from a vibrationally excited, electronic ground state 1,2‐difluoroethane intermediate. Selective vibrational excitation of fluorine reactions in isotopically mixed matrices t‐CHDCHD/C2H4/F2/N2 and CH2CD2/C2H4/F2/N2, and in matrices C2H2/C2H4/F2/N2 revealed a high degree of isotopic and molecular sel...

Gaseous Chloride Complexes Containing Halogen Bridges

Abstract: Publisher Summary This chapter discusses the gaseous chloride complexes containing halogen bridges. Most investigations have been concerned with chloride systems, and discussion of these therefore predominates here. In addition, however, extensive mass-spectrometric studies have been made on the formation of complexes by alkali fluorides. Other coordinatively unsaturated fluorides are as a rule of low volatility and, as a result, little suited for complex formation. Also, little work has been done with bromides and iodides. Good complex-forming species are those that are relatively quite volatile and with saturated vapors that contain appreciable concentrations of dimer. A method that always permits the detection of several complexes in the presence of one another and therefore permits the measurement of a specific complex in frequently occurring mixtures is mass spectrometry.

The Chemistry of the Halogen Azides

Abstract: Publisher Summary This chapter discusses the chemistry of the halogen azides Fluorine azide is best prepared from dry hydrazoic acid and fluorine in the gas phase Decomposition reactions of the fluorine azide are avoided when the reactants are diluted with N 2 Because in this reaction chlorine azide is produced in high concentrations locally, explosions can occur For preparative purposes, the most convenient method is the reaction of chlorine gas, diluted with nitrogen, with an aqueous solution of sodium azide Solutions of bromine azide in hexane, carbon tetrachloride, and other inert solvents are obtained from silver azide and bromine when the suspension contains some dry sodium sulfate, to avoid decomposition of the BrN 3 by traces of water For preparative purposes, solutions of bromine azide in dichloromethane or pentane can be prepared by addition of bromine to an agitated two-phase system held at 0°C, the aqueous phase of which consists of sodium azide and 30% HC1

Rhodium-containing carbonylation catalysts with halogen-containing promoter

Abstract: A catalyst system having high activity and selectivity to carbonylation products comprises a rhodium-containing catalytically active component and a halogen-containing promoter component, the halogen being selected from the group consisting of bromine, iodine, bromide compounds, and iodide compounds.

Fused n-phenylsulfonyl-n'-pyrimidinylureas and n- phenylsulfonyl-n'-triazinylureas

Abstract: of the Disclosure Fused N-phenylsulfonyl-N'-pyrimidinylureas and N-phenylsulfonyl-N'-triazinylureas Fused N-phenylsulfonyl-N'-pyrimidinylureas and N-phenylsulfonyl-N'-triazinylureas of the general formula (I), wherein Z is oxygen or sulfur, E is nitrogen or =CH-, R1 is hydrogen, halogen, nitro, C1-C4alkyl, C1-C4haloalkyl, cyano, or a -X-R5 , -CO-X-R6, -CO-NR7R8, -SO-R9 or -SO2-R10 group, R2 is hydrogen, C1-C4alkyl or C1-C4alkoxy, R3 is C1-C4alkyl C1-C4haloalkyl, C1-C4alkoxy, C1-4haloalkoxy C3-C6cycloalkyl, R4 is hydrogen, halogen, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy, C2-C4alkoxyalkoxy, C3-C6cycloalkyl or -NR11R12, R5 is C3-C5alkynyl or C1-C4alkyl which is unsubstituted or substituted by halogen or C1-C4-alkoxy, or is C3-C5alkenyl, which is unsubstituted or is substituted by halogen or C1-C4-alkoxy, R6 and R9 are each independently C1-C4alkyl, C1-C4haloalkyl, C2-C4alkoxyalkyl, C3-C5alkenyl, C3-C5alkynyl, phenyl or benzyl, R7 and R8 are each independently hydrogen, C1-C4alkyl, C1-C4halo-alkyl, C2-C4alkoxyalkyl, C3-C5alkenyl, C3-C5alkynyl, phenyl or benzyl, R10 is C1-C4alkyl, C1-C4alkoxy, C1-C4haloalkoxy or -NR13R14, R11 and R12 are each independently hydrogen or C1-C4alkyl, R13 and R14 are each independently hydrogen, C1-C4alkyl, C1-C4haloalkyl, C2-C4alkoxyalkyl, C3-C5alkenyl, C3-C5alkynyl, phenyl or benzyl, X is oxygen or sulfur, and A is an unsubstituted or substituted unsaturated bridge of 4 atoms, of the formula -CH=CH-Y-, wherein Y is a bridge member of 2 atoms which is selected from the series consisting of -NH-CO-, -NH-SO2-, -S-CO-, -S-SO2-, -O-CO- or -O-SO2-, and the salts thereof with amines, alkali metal or alkaline earth metal bases or with quarternary ammonium bases, have good pre- and postemergence selective herbicidal and growth regulating properties

Phenylpiperazine derivatives and process for producing the same

Abstract: NOVEL PHENYLPIPERAZINE DERIVATIVES AND PROCESS FOR PRODUCING THE SAME Abstract of the Disclosure: Compounds of the formula (wherein R1 is a lower alkyl group, R2, R3 and R4, which may be the same or different, represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a hydroxyl group, a trifluoromethyl group or a lower alkoxy-carbonyl group; two adjacent-groups of R2, R3 and R4 may combine to form a methylenedioxy group; n is an integer of 2 to 6) or salts thereof, are disclosed. These compounds are useful as agents for treating circulatory diseases because they have hypotensive action and are capable of increasing the cerebral blood flow, decreasing the heart rate and suppressing ventricular arrhythmia due to myocardial ischemia.

Process for the fluorination of a surface layer of shaped bodies made of plastics

Abstract: Method for the fluorination of a surface layer of articles molded from plastic, vulcanized rubber or other such macromolecular substances by the exposure of at least a part of the article's surface to a fluorine-yielding liquid in a controllable reaction, the liquid consisting of a solvent or solvent mixture containing dissolved elemental fluorine. Suitable solvents are especially halogen hydrocarbons in accordance with DIN 8962, which are liquid within a temperature range from -30° C. to +10° C., but also water and solvents having perfluoroalkyl groups. The liquid, in which a fluorine concentration between 0.5×10-3 and 1×10-2 mol/l is established by the introduction of fluorine diluted with inert gas, is used to treat the articles for about 20 seconds to 30 minutes; the fluorine can be activated if desired. The liquid can additionally contain sulfur dioxide, oxygen, carbon monoxide, chlorine, bromine, or mixtures thereof.

Photochemical dehalogenation of polyhalobenzenes. I: Survey of the reactivity in hexane solution

Abstract: Photochemical dechlorinations and debrominations of C6HnX6−n (X=Cl, Br) isomers were carried out in hexane. The products and residual reactant were determined quantitatively by means of gas chromatography. From these experiments, the relative rates of dehalogenation were obtained. The different rates among unequivalent sites in a molecule were interpreted by the effect of steric acceleration by the neighboring halogen atom(s). The reactivity of the halogen atom in polyhalobenzene towards photochemical elimination reaction is dependent both on its position in the molecule when compared among isomers and on the number of halogen atoms in a molecule when compared among polyhalobenzenes of various degrees of substitution. The latter effect is more predominant in the series of polybromobenzenes.

Reaction of fluorine atoms with alkyl iodides: a possible observation of the Walden inversion in the gas phase

Abstract: Evidence is presented to show that The Walden Inversion does take place in these gaseous reactions. CO/sub 2/ laser radiation of a mixture of SF/sub 6/ and alkyl iodides at equal pressures dissociated the SF/sup 6/ to F and SF/sup 5/. One ..mu..s later, the alkyl iodides were dissociated by a pulse from a dye laser. The experiment was repeated at 5 Hz. The resulting fluorescence intensities at 304.7 nm and 306.7 nm for I/sup */ atoms and excited I atoms are shown for methyl, ethyl, isopropyl, and tert-butyl iodide. From the relative intensities produced, conclusions can be drawn that a tertiary iodide does not produce any iodine atoms, while a primary iodide produces many more. Tests were performed to show that the iodine atoms were not photodissociated from the alkyl iodide cy the CO/sub 2/ laser or by 2-photon dissociation by the dye laser of the radical products of competing reactions. In the absence of SF/sub 6/, CO/sub 2/ laser pulses did not produce additional I atoms. 1 figure.

Benzoylurea compounds, and pesticidal compositions comprising same

Abstract: The invention relates to new benzoylurea compounds of the general formula wherein R, is a halogen atom, R2 is a hydrogen atom or a halogen atom, R3 is a hydrogen atom or represents 1 or 2 substituents which are selected from the group consisting of chlorine, methyl and trifluoromethyl, R4 is a hydrogen atom, an alkyl group having 1-6 carbon atoms or a cycloalkyl group having 3-6 carbon atoms, R5 is a hydrogen atom or an alkyl group having 1-4 carbon atoms, and A ist a phenyl group or a heteroaryl group having 1 or 2 nitrogen atoms, which groups may be substituted with 1-3 substituents which are selected from the group consisting of halogen, and alkyl, alkoxy, haloalkyl and haloalkoxy having 1-4 carbon atoms. The compounds have an insecticidal and acaricidal activity. After having been processed to compositions, the compounds may be used for control of insects and/or mites in a dosage from 1 to 5000 g of active substance per hectare. In addition the compounds have an anti-tumor activity and may be used in pharmaceutical compositions.

Kinetics of formation of krypton‐halogen atom exciplexes in electron beam irradiated gases

Abstract: The formation of KrCl*, KrBr*, and KrF* exciplexes, in electron beam irradiated mixtures of krypton with either CF3Cl, CF3Br, SF6, or CF4, are observed to be formed by two distinct and kinetically resolvable time‐dependent processes. The rate of one process is total electron beam energy (dose per pulse) independent but dependent on the partial pressures of the halogen source. This process is attributed to a reaction between high electronic excited states of krypton and the halogen source. The second process is dependent on the total absorbed electron beam energy per pulse and is shown to be due to ion recombination processes. Specifically, the formation is due to a combination of krypton positive ions and halogen negative ions, the latter being formed by dissociative electron capture by the halogen source. This process produces KrF* in high vibrational levels.

Hydrogen-bromine cell

Abstract: Described herein is an energy storage device which utilizes a hydrogen/bromine cell. The cell includes a bromine electrode and a hydrogen electrode. The cell is light weight, resists corrosion caused by bromine or hydrobromic acid and uses both an electrolysis and a fuel cell reaction to store or discharge electrical energy. The cell frame is made of graphite and has a pyrographite coating on at least the portion facing the bromine electrode. This cell is therefore very useful in matching varying energy supplies with varying energy demands and allows for decentralization of energy storage.

Reactive dyestuffs of the dioxazine series, their preparation and their use

Abstract: Reactive dyes of the formula where (R)n represents n R substituents which independently can be C1-4-alkyl, C1-4-alkoxy, carboxyl or halogen, n is 0-3, m is 1-2, and X is a radical of the formula where R1 and R2 are independently hydrogen or substituted or unsubstituted C1-4-alkyl, A is C3-7-alkylene, which may be halogen-, hydroxyl-, carboxyl-, sulpho-, phenyl-, sulphophenyl- or C1-4-alkoxycarbonyl-substituted, or cyclohexylene, which may be C1-4-alkyl-substituted, or where the group -N(R1)-A-N(R2)- is 1,4-piperazinediyl, and Y is fluorine, -NH2 or a substituted amino group, are suitable for dyeing and printing cellulose-containing fibre materials, producing wet- and light-fast dyeings in bright blue shades.

INTRODUCTION OF SULFUR IN COMPOUNDS WITH REACTIVE HALOGEN ATOMS VIA THE t-BUTYLTHIOLATE ANION

Abstract: The preparation of t-butylthioethers from examples of halogen substituted heterocycles are described. S-Dealkylation of the t-butylthioethers readily takes place by pyrolyses with catalytic amounts of aluminum chloride or p-toluenesulfonic acid.

Method of forming film of fluoroalkyl acrylate polymer on surface of base body

Abstract: PURPOSE:To improve the adhesiveness of a fluoroalkyl acrylate film useful as a resist material, by treating the surface of a slicon wafer with a sliane coupling agent. CONSTITUTION:A silicon compound represented by the formulaI(in the formula, Rf is a perfluoroalkyl-alkyl or per-fluoroalkyl-oxy-alkyl group, and at least one of R1, R2 and R3 is chlorine atom or a 1-5C alkoxy group, while the remainder is hydrogen atom, a 1-5C alkyl or hydroxyl group or Rf) is applied to the surface of a silicon wafer. Fluoroalkyl acrylate represented by the formula II (R4 is a methyl group in which at least one hydrogen atom may be optionally substituted with halogen atom, or halogen or hydrogen atom, R5 is a 1-6C hydrocarbon group, and R5 is a 1-15C alkyl group in which at least one hydrogen is substituted with fluorine atom) is then applied thereto.

Raman and visible-ultraviolet spectra of polyhalide anions in molten molecular iodine/potassium iodide-lithium iodide, molecular iodine/cesium chloride-lithium chloride, and molecular iodine-iodine chloride/cesium chloride-lithium chloride

Abstract: Molten eutectic mixtures of KI-LiI and CsCl-LiCl at 300-400/sup 0/C were equilibrated with I/sub 2/ vapor or I/sub 2/-ICl vapor at pressures of 0.002-2 atm and were investigated by means of Raman and visible-UV spectroscopy. The observed polarized Raman bands were attributed to the symmetric stretching vibrations of I/sub 3//sup -/ (112 cm/sup -1/), I/sub 2/Cl/sup -/ (184 cm/sup -1/), and ICl/sub 2//sup -/ (271 cm/sup -1/). Further evidence for the presence of these trihalide anions in the melts was given by the visible-UV spectra. A band at 161 cm/sup -1/ in the Raman spectrum of the I/sub 2//KI-LiI melt was attributed to a polyiodide of higher molecular weight than the triodide. There is evidence for the disproportionation of I/sub 2/Cl/sup -/ in the I/sub 2//CsCl-LiCl melt.

Halogen trapping agent and trapping method

Abstract: PURPOSE: To trap halogen with an excellent effect of reduction, by bringing a synthetic macromolecular compound containing a water-soluble metal salt of halogen, etc. into contact with a magnesium oxide solid solution represented by a specified formula in the presence of H 2 O. CONSTITUTION: By baking a hydrotalsite compound at about 500W700°C, a magnesium oxide solid solution represented by Formula (with the proviso of 0

Competition Reactions at α ‐ Fe2 O 3 Photoanodes

Abstract: Photoanodic oxidation of iodide and bromide ions at polycrystalline doped ..cap alpha..-Fe/sub 2/O/sub 3/ electrodes in competition with oxygen production was investigated in the pH range 0-13 in aqueous media. It appears that at high pH values only iodide oxidation could compete effectively with water oxidation. However, in addition to the photoelectrochemical oxidation of iodide, evidence for secondary reactions involving electrogenerated species was observed mainly in highly basic solutions. Adsorption of I/sup -/ plays a significant role in the reaction as well as in the photoelectrochemical properties of ..cap alpha..-Fe/sub 2/O/sub 3/. ..cap alpha..-Fe/sub 2/O/sub 3/ photoanodes were found to be stable under illumination in solution at pH 0 with or without the presence of bromide ions. 13 references, 5 figures, 1 table.

Bromine and Iodine Adsorption on an Fe(100) Surface

Abstract: We studied bromine and iodine adsorption on an Fe(100) surface in the temperature range of 110 K to 700 K. In this communication we compare core-level binding energies of dissociatively and molecularly adsorbed halogen species as a function of coverage. Our valence band photoemission data suggest that bromine and iodine adsorption at 300 K is always dissociative. At 110 K, initial dissociative adsorption is followed by condensation of molecular halogens. At 300 K the core-level binding energies EBF of bromine and iodine decrease as a function of coverage by 0.2 eV and 0.7 eV, respectively. The EBF values found for the condensed molecular species are identical to or even lower by 0.3 eV than for the room temperature saturated bromine and iodine overlayers, respectively.