Treatment with 2 -fluorinated

Treatment of coal with chlorine or bromine results in addition and substitution reactions. At temperatures up to 600°C chlorinolysis produces carbon tetrachloride, phosgene, and thionyl chloride (73). Treatment with fluorine or chlorine trifluoride at atmospheric pressure and 300°C can produce large yields of Hquid products. 

Pentafluorophenylditelluridc yields 79-80% pentafluorophenyltellunum tri fluoride on treatment with fluorine or xenon difluoride [105] The fluonnated tetravalent tellurium can be further oxidized to hexavalent tellurium with either xenon difluoride [/22] or fluorine [123]... 

Polymer-bound phenyliodine difluoride, which also has been used as a reagent to add fluorine to alkenes, can be prepared by the addition of xenon difluoride to the polymer [134, 135 136] Methyl iodide is converted to trifluoro methyliodine difluoride by treatment with fluorine at -110 C [137] Perfluoro-alkyliodine tetrafluorides could be synthesized from the perfluoroalkyliodine difluorides and fluorine [138] or chlorine trifluoride [139] Perfluoroalkyl [140] and perfluoroaryl [141] iodides are oxidized to the corresponding iodine difluorides by chlorine trifluoride. 

P pentachloride causes ignition on contact with Al powder (Ref 2), while contact with a mixt of chlorine and chlorine dioxide usually results in expln, possibly due to formation of the more sensitive chlorine monoxide (Ref 5). Interaction with diphosphorus trioxide is rather violent at ambient temp (Ref 3) treatment with fluorine causes the entire mass to become incandescent (Ref 1). Ignition occurs when hydroxylamine is mixed with P pentachloride (Ref 6), while mixts with Mg oxide react with brilliant incandescence (Ref 7). The residue from interaction of P pentachloride and anilide in benz and removal of solvent and phosphoryl chloride in vacuo expld violently on admission of air (Ref 12). A soln of P pentachloride in nitrobenzene is stable at 110°, but begins to de-... 

In studying the reactivity of iV-fluoropyridinium fluoride 127 obtained from pyridine 126 by treatment with fluorine gas in chloroform at low temperature (Scheme 30), Kiselyov studied reactions with isocyanides in the presence of trimethylsilylazide <2005TL4851>. A mixture of products was obtained in which, besides tetrazolylpyr-idine 128 and a nicotinamide derivative 129 also tetrazolo[l,5-tf]pyridine 1 was obtained in very poor yield (5-10%). 

Treatment with fluorine/nitrogen mixtures (fluorination) increases the polar component of the surface energy initially, but longer treatment times result in a drop in both the polar component and the total surface energy24 25 (see Figure 16.3). At very long treatment times the surface energy ofthe treated surface can be lower than that of the polyolefin itself. 

Lanthanide trichlorides can be converted into the corresponding trifluorides by treatment with fluorine (20), or aluminum fluoride (melt) (22). 

The 1980s saw major developments in secondary synthesis and modification chemistry of zeolites. SUicon-enriched frameworks of over a dozen zeolites were described using methods of (i) thermochemical modification (prolonged steaming) with or without subsequent acid extraction, (ii) mild aqueous ammonium fluorosilicate chemistry, (iii) high-temperature treatment with silicon tetrachloride and (iv) low-temperature treatment with fluorine gas. Similarly, framework metal substitution using mild aqueous ammonium fluorometaUate chemistry was reported to incorporate iron, titanium, chromium and tin into zeolite frameworks by secondary synthesis techniques. 

The dissociation equilibrium of tetrafluorohydrazine has been studied by four different methods, all of which have given heats of dissociation for the N-N bond in the range 80-91 kJ mol-1 (69). In the first, gaseous, N2F4 was heated to a series of temperatures in the range 100-150°C in a metal vessel, the inner surface of which had been passivated by treatment with fluorine. Measurements of the pressure at constant volume as a function of temperature gave the heat of dissociation as 83.05 0.2 kJ mol-1 (165). 

Treatment with fluorine presumably completes the oxidation according to the... 

Chemical surface modification methods of gas-separation membranes include treatment with fluorine, chlorine, bromine, or ozone. These treatments result in an increase in membrane selectivity with a decrease in flux. Cross-linking of polymers is often applied to improve the chemical stability and selectivity of membranes for reverse osmosis, pervaporation, and gas-separation applications (41). Mosqueda-Jimenez and co-workers studied the addition of surface modifying macromolecules, and the use of the additive... 

The suggestions are of course given only in a rough and simplified form in the preceding list. For example, after-treatment with fluorinated compounds was also suggested (44, 45). A silica gel that has been after-treated with hydrofluoric acid develops hydrophobic characteristics to the same extent as Aerosil R 972, which is after-treated with dichlorodimethyl-silane. Figure 3 (46) demonstrates the different behavior of Aerosil 130 (the untreated synthetic amorphous silica) and Aerosil R 972 for water adsorption. 

The suggestions are of course given only in a rough and simplified form in the preceding list. For example, after-treatment with fluorinated compounds was also suggested [44,45]. A silica gel that has been after-treated... 

Dienes.—Poly(perfluorobuta-l,3-diene), prepared by free-radical polymerisation of the monomer initiated with bistrifluoromethyl peroxide, di-iso-propyl peroxydicarbonate, or benzoyl peroxide, has been cross-linked by treatment with fluorine and with hexamethylenediamine. ... 

Brueck [22] studied the electrostatic properties of a triboelectric series of polymers having polyethyleneimine at the positive end and a hexafluoropropy-lene-tetrafluoroethylene copolymer at the negative end. Various commercial polymers were compared to the polymers of the triboelectric series. The effects of different polar groups were in the order (from most positive to most negative) imino = oxy, carbonate urethane = aliphatic carboxylate ester, carboxyamide, hydroxy, cyano, aliphatic hydrocarbon aromatic hydrocarbon, arenecarboxy-late carboxylic acid, nitrate chloro, fluoro. Surface treatments with fluorinated surfactants drastically altered the charging properties of polymers. 

Electrochemical fluorination leads to fragmentation, coupling, and rearrangement reactions as well as giving the perfluorinated product. In addition, small amounts of hydrogen can be retained in the cmde product. The products are purified by treatment with base to remove the hydrogen-containing species and subsequently distilled. 

As opposed to ECF, direct fluorination affords a much lower degree of isomerization so that the carbon skeleton of the reactant remains intact in the perfluorinated product. Direct fluorination is also complementary to ECF in the significantly higher yields observed for the direct fluorination of ethers. As with ECF the products are purified by treatment with base and subsequent distillation. 

Direct fluorination involves the treatment of an appropriate hydrocarbon precursor dissolved in an inert Hquid with fluorine gas to yield a perfluorinated precursor to a long-chain carboxyflc acid. Equations 2 and 3 illustrate the process for perfluorooctadecanoic acid (17). 

The chemical resistance of PTFE is exceptional. There are no solvents and it is attacked at room temperature only by molten alkali metals and in some cases by fluorine. Treatment with a solution of sodium metal in liquid ammonia will sufficiently alter the surface of a PTFE sample to enable it to be cemented to other materials using epoxide resin adhesives. 

Alkyl fluorides have been prepared by reaction between elementary fluorine and the paraffins, by the addition of hydrogen fluoride to olefins, by the reaction of alkyl halides with mercurous fluoride, with mercuric fluoride, with silver fluoride, or with potassium fluoride under pressure. The procedure used is based on that of Hoffmann involving interaction at atmospheric pressure of anhydrous potassium fluoride with an alkyl halide in the presence of ethylene glycol as a solvent for the inorganic fluoride a small amount of olefin accompanies the alkyl fluoride produced and is readily removed by treatment with bromine-potassium bromide solution. Methods for the preparation of alkyl monofluorides have been reviewed. ... 

Fluorinatton of graphite with fluorine gives graphite fluorides that have interesting properties, as recently reviewed [63]. Pyridine and its derivatives add elemental fluorine to form unstable N-fluoro adducts [14, 26, 64, 65]. These may decompose to 2-fluoropyndines [65] or be stabilized by treatment with inflate salts to form useful electrophilic fluonnating agents [64]... 

Fluorination of naphthalene in a stream of dilute fluorine over cobalt trifluoride yields a mixture of perfluorodecalins and partially fluorinated naphthalene derivatives that are fully fluorinated to perfluorodecalins by a subsequent treatment with dilute fluorine [23] Perfluorodecalins are also final products ot fluorination of tetralin over cobalt trifluoride at 250 °C. A more thorough investigation of this reacPon revealed seven additional compounds as products and intermediates [//] (equation 6). 

Perfluorodimethyladamantane is prepared from adamantane dicarboxylic acid by treatment with sulfur tetrafluoride followed by energetic fluorination with cobalt trifluoride over two temperature ranges [S] (equation 15)... 

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