Bromine oxide fluorides

These compounds are less numerous and rather less studied than their chlorine analogues indeed, until fairly recently only FBr02 was well characterized. The known species are  

Oxidation state of Br Cations Neutral species Anions 

Despite several attempts at synthesis, there is little or no evidence for the existence of FBrO, p3Br02 or FsBrO. The bromine oxide fluorides are somewhat less thermally stable than their chlorine analogues and somewhat more reactive chemically. The structures are as already described for the chlorine oxide fluorides (Fig. 17.26). 

Bromyl fluoride, FBr02, is a colourless liquid, mp —9°, which attacks glass at room temperature and which undergoes rapid decomposition 

It is best prepared by fluorine transfer reactions such as 

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Chlorine Dioxide See under Chlorine Oxides Chlorine Fluorides Although in 1891, H. Moissan (cited in Ref 2) easily prepd bromine iodine fluorides by direct action of the corresponding elements, he claimed that it was impossible to obt any chlorine fluoride. Other investigators among them Lebeau(1906, cited in Ref 2) and Ruff Zedner(1909 cited in Ref 2) also tried, but failed. It was not until 1928 that Ruff et al (Ref 3) succeeded in prepg the monocompd Chlorine Monofluoride, C1F, mw 54.46 colorless gas, fr p -154, bp 100.8, d 1.62 at -100° critical temp -14°, Q evapn 2.27 kcal/mol was prepd by action of si moist chlorine on fluorine at RT if the gases are dry they do... 

Presumably because of its lower electronegativity, bromine can stabilize Mo(V) as MoOBr8 but not Mo (VI) as MoOBr4. There are no reported molybdenum oxide iodides and no lower-valent [molybdenum(V) or molybdenum(IV)] oxide fluorides. The combination of oxygen plus chlorine can stabilize Mo (VI) in both M0O2CI2 and MoOCU, but MoCl is apparently unstable at room temperature. 

In contrast to the chemical oxidation of hydrazones with iodine monofluoridc. bromine tri-fluoride, bromine monofluoride, or elemental fluorine, which provides the corresponding gem-inally difluorinated compounds (vide supra), monofluorination of diaryl ketone hydrazones can be achieved by anodic oxidation in the presence of fluoride ions (Table 5). In this case geni-... 

The mechanism of displacement of chlorine and bromine by fluoride from the side chain of these systems is of interest. It has been suggested that an Sn2 type of displacement of fluorine from 3-trifluoromethylquinoline occurs in reactions with sodium eth-oxide [141] (Figure 9.55), and a similar process could account for the displacements of chloride or bromide by fluoride from 9.54A that were indicated in Figure 9.54. 

NIOSH REL (Chromium(VI)) TWA 0.025 mg(Cr(VI))/mh CL 0.05/15M SAFETY PROFILE Confirmed human carcinogen. Poison by subcutaneous route. Mutation data reported. A powerful oxidizer. A powerful irritant of skin, eyes, and mucous membranes. Can cause a dermatitis, bronchoasthma, chrome holes, damage to the eyes. Dangerously reactive. Incompatible with acetic acid, acetic anhydride, tetrahydronaphthalene, acetone, alcohols, alkali metals, ammonia, arsenic, bromine penta fluoride, butyric acid, n,n-dimethylformamide, hydrogen sulfide, peroxyformic acid, phosphorus, potassium hexacyanoferrate, pyridine, selenium. 

Oxygen fluorides were described in Section 15.7. Iodine is the only halogen to form an oxide which is thermodynamically stable with respect to decomposition into its elements (equation 16.38). The chlorine and bromine oxides are hazardous materials with a tendency to explode. 

ACIDE SULFHYDRIQUE (French) (7783-06-4) A highly flammable and reactive gas. Violent reaction with strong oxidizers, metal oxides, metal dusts and powders, bromine penta-fluoride, chlorine trifluoride, chromium trioxide, chromyl chloride, dichlorine oxide, nitrogen trichloride, nitryl hypofluorite, oxygen difluoride, perchloryl fluoride, phospham, phosphorus persulfide, silver fulminate, soda-lime, sodium peroxide. Incompatible with acetaldehyde, chlorine monoxide, chromic acid, chromic anhydride, copper, nitric acid, phenyldiazonium-chloride, sodium. Forms explosive material with benzenediazonium salts. Flow or agitation of substance may generate electrostatic charges due to low conductivity. Attacks many metals. 

ANTIMONY or ANTIMONY BLACK (7440-36-0) Dust or powder forms explosive mixture with air. Reacts violently with strong oxidizers and acids, especially halogenated acids, producing toxic stibine gas (antimony hydride). Reacts violently with anunonium nitrate, bromine, bromine azide, bromine tri fluoride, bromoazide, chloric acid, chlorine, chlorine monoxide, chlorine trifluoride, dichlorine oxide, disulfur dibromide, fluorine, halogens, iodine, iodine pentafluoride, nitrosyl fluoride, nitryl fluoride, potassium dioxide, potassium nitrate, potassium permanganate, potassium peroxide, sodium nitrate, sodium peroxide. Forms explosive V-chlorodimethylamines with chloric and perchloric acid. 

Reaction (17) has been used to prepare the new oxide fluoride of bromine(v). Vibrational spectra imply that the compound is isostructural with... 

Bromine(III) fluoride fluorinates everything which dissolves in it. Numerous oxides, halides and salts of oxyacids are converted into fluorides. Carbonates, nitrates and iodates are usually completely converted into the fluorides, while some of the metal oxides, such as BeO, MgO, ZnO or AI2O3 are only partly fluorinated by liquid bromine(III) fluoride. Sodium vanadate yields a mixture of tetrafluorooxovanadate and hexafluorovanadate i, potassium or silver dichromates give KCrOF4 and AgCrOF4 resp. i. Potassium permanganate is converted into KMnFs, potassium metaphosphate into potassium hexafluoro-phosphate and sodium borate into the tetrafluoroborate ... 

Bromine ttifluoride is commercially available at a minimum purity of 98% (108). Free Br2 is maintained at less than 2%. Other minor impurities are HF and BrF. Free Br2 content estimates are based on color, with material containing less than 0.5% Br2 having a straw color, and ca 2% Br2 an amber-red color. Fluoride content can be obtained by controlled hydrolysis of a sample and standard analysis for fluorine content. Bromine ttifluoride is too high boiling and reactive for gas chromatographic analysis. It is shipped as a Hquid in steel cylinders in quantities of 91 kg or less. The cylinders are fitted with either a valve or plug to faciUtate insertion of a dip tube. Bromine ttifluoride is classified as an oxidizer and poison by DOT. 

The oxidation may be carried out with an inert solvent thermally (35), with a sensitizer such as bromine (36), with uv radiation (37), or over a suitable catalyst (38). Principal by-products of all these oxidation processes are the acyl fluoride products derived from oxidative cleavage of the perfluoroaLkene (eq. 

Ha.logen Compounds. Fluorine is unreactive toward ozone at ordinary temperatures. Chlorine is oxidized to Cl20 and Cl20y, bromine to Br Og, and iodine to I2O2 and I4O2. Oxidation of haUde ions by ozone increases with the atomic number of haUde. Fluoride is unreactive chloride reacts slowly, ultimately forming chlorate and bromide is readily oxidized to hypobromite (38). Oxidation of iodide is extremely rapid, initially yielding hypoiodite the estimated rate constant is 2 x 10 (39). HypohaUte ions are oxidized to haUtes hypobromite reacts faster than hypochlorite (40). 

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