Iodine trifluoride preparation

Also, it may be prepared by the reaction of fluorine with iodine trifluoride or heating potassium iodide with a stoichiometric amount of fluorine ... 

Bromine monofluoride or iodine monofluoride can be prepared from the corresponding elements in trichlorofluoromethane at — 781 and — 45 C,2,3 respectively. The compounds are unstable and decompose at low temperatures, iodine monofluoridc at — 14 C2,3 and bromine monofluoride, in part, even at — 78 C.1 Therefore, they are used, without separation and purification, in Freon solutions at low temperatures or, most frequently, as stoichiometric mixtures bromine trifluoride/bromine and iodine pentafluoride/iodine. A solution of iodine monofluoride, obtained by bubbling nitrogen-diluted fluorine gas into a suspension of iodine in trichlorofluoromethane at — 75 C, was used for addition to alkene C = C bonds. The reaction is regioselective and in most cases obeys the Markovnikov rule.4 Iodine monofiuoride prepared in situ reacts quite efficiently with steroidal alkenes.4... 

The halogen fluorides are binary compounds of bromine, chlorine, and iodine with fluorine. Of the eight known compounds, only bromine trifluoride, chlorine trifluoride, and iodine pentafluoride have been of commercial importance. Properties and appHcations have been reviewed (1 7) as have the reactions with organic compounds (8). Reviews covering the methods of preparation, properties, and analytical chemistry of the halogen fluorides are also available (9). 

The halogen fluorides are best prepared by the reaction of fluorine with the corresponding halogen. These compounds are powerful oxidising agents chlorine trifluoride approaches the reactivity of fluorine. In descending order of reactivity the halogen fluorides are chlorine pentafluoride [13637-63-3] 1 5 chlorine trifluoride [7790-91-2] 3 bromine pentafluoride [7789-30-2], BrF iodine heptafluoride [16921 -96-3], chlorine... 

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. 

The polymerization of 1,3,3-trimethyl-2,7-dioxabicyclo[2.2.1 Jheptane 35 was carried out in methylene chloride, toluene, and 1-nitropropane at temperatures between —78 and 0 °C32l Boron trifluoride etherate, triethyloxonium tetrafluoro-borate, antimony pentachloride, and iodine were used as initiators. Irrespective of the solvents and initiators employed, the products obtained at 0 °C were white powders with melting points of 50—55 °C, while those obtained at tower temperatures were sirups. The number average molecular weight of the unfractionated products ranged from 400 to 600. The molecular weight distribution of the oligomers prepared at 0 °C was broad, in contrast to the relatively narrow distribution of those obtained at -40 °C. 

Diborane is prepared by the reaction of sodium borohydride with iodine or boron trifluoride or trichloride in diglyme ... 

The stoichiometric equivalents of bromine monofluoride and iodine monofluoride are obtained by reacting bromine trifluoride with bromine and iodine pentafluoride with 2 equivalents of iodine. A convenient procedure for the preparation of bromine trifluoride from bromine and fluorine has been described.6 Iodine pentafluoride can be obtained by passing fluorine gas over solid7 or molten8 iodine. 

The mixtures bromine trifluoride/bromine and iodine pentafluoride/iodine can be successfully employed to prepare bromo- and iodo-substituted fluoroalkanes by addition to poly-fluoroalkenes. The reactions are carried out, in the presence of catalysts aluminum, aluminum/ aluminum triiodide9 or without a catalyst,10 in steel reactors at room temperature or with heating. In most cases the addition products are obtained in high yield (see Table 1). 

Pentafluorocthyl iodide is of practical interest, particularly as a precursor of higher perfluoroal-kyl iodides. There are several patents for the preparation of the key compound from tetra-fluoroethene, iodine pentafluoride and iodine at 75-80 C in the presence of catalysts anti-mony(III) fluoride, titanium(lV) chloride, boron trifluoride, vanadium(V) fluoride, niobium(V) fluoride, and molybdenum(Vl) fluoride.11-13 The agents iodine monofluoride" and bromine monofluoride" can add to branched pcrfluoroalkcnes, e.g. perfluoro-2-methylbut-2-ene gives perfluoro-2-iodo-2-methylbutane.1415... 

Although the last method gives satisfactory results, it requires a large excess of iodine monofluoride which has to be prepared from iodine and fluorine just prior to use. Furthermore, most of the unsubstituted hydrazones are rather unstable and undergo transformation into azines which are unrcactive towards iodine monofluoride. O-Methyloximes are also inactive with respect to iodine monofluoride. The procedure with bromine trifluoride is free of such limitations. 

If cyclopentadienyliron dicarbonyl halides are allowed to react with themselves in the presence of Lewis acids, cations are formed in which the new substituent is the cyclopentadienyliron dicarbonyl halide itself, for example, [CjH6Fe(CO)i-X-(CO)2-FeC8H8]+ (X = Cl, Br, I). All three cations can be prepared best by treatment of the corresponding halides with boron trifluoride diethyl etherate all are isolated as tetrafluoro-borates.18 The bromine complex can also be obtained by a more complicated procedure by the reaction between C8H8Fe-(CO)2Br and AlBr3 in liquid sulfur dioxide 16 the iodine cation can be isolated from a melt of cyclopentadienyliron dicarbonyl iodide and aluminum chloride.17 In the latter two cases the hexafluorophosphate salts can be obtained. These binuclear cations are of special interest, because they are cleaved by electron donors,16-17 e.g., aniline, pyridine, benzonitrile, acetonitrile, acrylonitrile, with the formation of the corresponding [C8H8Fe(CO)2L]+ cations and the parent halide. Equations for preparation of the tetrafluoroborate are ... 

As already noted, azines are unreactive towards iodine monofluoride however, it has been shown that azines react with bromine trifluoride under mild reaction conditions, yielding ew-difluorides (Table 1). The reagent bromine trifluoride is readily prepared from its elements, although caution should be taken because bromine trifluoride reacts violently with water and acetone. 2,4-Dinitrophcnylhydrazonescan also be used as the hydrazonederivatives in reactions with bromine trifluoride (Table 2). No significant byproducts, unlike the reactions with iodine monofluoride, are obtained in this case. The reactions with bromine trifluoride are not sensitive to the stereochemistry of the C = N bond, and both E- and Z-isomers react with the same efficiency. 

The preparation of gew-difluoro compounds can be achieved by the reaction of oximes with nitrosonium tetrafluoroborate in pyrtdinium poly(hydrogen fluoride) [NO BF4, (HF) /pyr-idine] (Tabic 6, entries 1 -8). Some examples of reactions of oximes and oxime methyl ethers with iodine monofluoridc and bromine trifluoride" have also been reported (Table 6, entries... 

Boron Tribromide and Boron Triiodide. Boron tribromide is prepared commercially in relatively small quantities by the bromination of boron carbide, and its commercial use is limited. No commercial use for boron triiodide has been reported. Laboratory quantities of boron tribromide can be prepared by the reaction of aluminum bromide with boron trifluoride or a metal fluoroborate. Boron triiodide can be prepared in small quantities by the reaction of boron or a metal tetrahydroborate with iodine. 

Iodine oxide trifluoride, a colorless crystalline solid, is prepared by dissolving I2O5 mboilmgIFs followed by cooling. Above 110 °C it thermally dismutates into FIO2 and IF5. 

Iodine dioxide trifluoride can be prepared by partial fluorination of Ba3H4(106)2 with HSO3F. It decomposes upon heating (97 °C) to yield IOF3 and O2. It is highly associated under all conditions. It reacts with AsFs, SbFs, NbFs, and TaFs to form oxygen-bridged polymers. 

Both chlorines in the iminium chloride (27) can be replaced by fluorine, bromine or iodine, giving compounds (58)-(60) (Scheme 3) if the salt is treated with the corresponding hydrogen halide under anhydrous conditions. By chloro-iodo exchange with HI from the 3-chloroacrylamide chloride the corresponding amide iodide (61 equation 37) was prepared. Dimethylformamide chloride (27) is converted by methyl iodide to dimethylformamide iodide (59). Remarkably the difluoro compound (60) is a nonionic, distillable liquid which can be ionized by addition of boron trifluoride. ... 

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