Free-radical halogenation distribution". For propane and higher alkanes, the hydrogen atoms which form part of CH (or CH) groups are preferentially replaced. The reactivity of the different halogens varies considerably. The relative rates are: fluorine (108) > chlorine (1) > bromine (7 × 10) > iodine (2 × 10). Hence, the reaction of alkanes with fluorine is difficult to control, that with chlorine is moderate to fast, that with bromine is slow and requires high levels of UV irradiation while the reaction with iodine is practically nonexistent and thermodynamically unfavorable. A common method in organic synthesis employing is the Wohl–Ziegler reaction, which
Bromine pentafluoride an excess of fluorine: For the preparation of smaller amounts, potassium bromide is used: This route yields bromine pentafluoride almost completely free of trifluorides and other impurities. Bromine pentafluoride reacts violently with water, but when moderated by dilution with acetonitrile, it will form bromic acid and hydrofluoric acid, simple hydrolysis products: It is an extremely effective fluorinating agent, converting most uranium compounds to the hexafluoride at room temperature. Bromine pentafluoride is severely corrosive to the skin, and its vapors are irritating to the eyes, skin, and mucous membranes. Exposure to 100 ppm for a few minutes is lethal to most