Oxyhalogenation

Water reacts violently with aH halogen fluorides. The hydrolysis process can be moderate by cooling or dilution. In addition to HF, the products may include oxygen, free halogens (except for fluorine), and oxyhalogen acids. 

It is convenient to classify here the decompositions of metal salts of the various oxyhalogen acids on the basis of the oxygen content of the anion, with subsections devoted to the metals of a particular sub-group of the Periodic Table. Again, consideration of the ammonium salts is deferred to Sect. 4. As noted elsewhere in this review, some reports are not explicit as to whether or not melting accompanies reaction thermal analysis studies can be valuable [843]. 

The high values of E generally characteristic of the decomposition reactions of metal oxyhalides are widely interpreted as evidence that the initial step in anion breakdown is the rupture of the X—O bond and that the energy barrier to this reaction is not very sensitive to the properties of the cation present. Information of use in the formulation of reaction mechanisms has been obtained from radiolytic studies of oxyhalogen salts [887-889],... 

Pantsar-Kallio M, Manninen PKG. 1998. Speciation of halogenides and oxyhalogens by ion chromatography-inductively coupled plasma mass spectrometry. Anal Chim Acta 360 161-166. 

Salts of Ordinary Oxygen Acids.—Among the ordinary oxygen salts are included the oxyhalogens the nitrates and the nitrites the carbonates the phosphates, phosphites, and hypophosphites the sulfates and sulfites the borates and the silicates. These may be divided into (a) oxidizing salts and (b) reducing salts. 

Vanadium Oxytrichloride, VOCl3, commonly known as vanadyl chloride, is the easiest to prepare of all the halogen or oxyhalogen compounds of vanadium. It distils over as a yellow liquid when vanadium pentoxide is strongly heated, or when vanadiun trioxide is gently heated, in a current of chlorine. Addition of charcoal accelerates the reactions 9... 

Rothenberg G, Clark JH (2000) On Oxyhalogenation, Acids, and Non-Mimics of Bromoperoxidase Enzymes. Green Chem 2 248... 

Acidic chlorate oxidations are also carried out with a small amount of chloride, and according to the reaction conditions, different equilibria predominate.37 With these reaction systems, the oxidizing oxyhalogen species, formed in situ, promotes the oxidation of the primary alcohol groups of polysaccharides to carboxylic acids.36 Thus, the stoichiometry of the overall oxidation in strongly acidic medium (85% H3P04) is given by Eq. (24). 

The effectiveness of various chlorine oxidants, and the influence of the pH, on D-galacturonic acid has been studied (see Ref. 1, p. 1120). The autocatalytic chlorite oxidation of polysaccharides is similar to that described for the bromate oxidation (see Section II.2). Thus, the reactive oxyhalogen species are reduced to halides, as shown in Eq. (26). 

Water samples Bromine, chlorine and iodine Eight halogenides and oxyhalogens Ion chromatography 500 ng ml"1 Cl 10 ng ml"1 Br 0.1 ng ml"1 iodide PantsarKallio and Manninen (1998)... 

Since many oxyhalogen salts decompose in the solid state, melting points are available for relatively few compounds. In some cases the decomposition is slow enough that the melting point of a nearly pure salt can be measured. Values have been listed whenever possible, even if they are not very precise. 

Since the chemistry of the individual classes of oxyhalogens, i.e., chlorine, bromine, and iodine, are independent of each other, they have been placed in separate chapters, each with their own references. 

An exceptional oxidant in oxyhalogenation is acetyl hypofluorite that chlorinates and brominates pyridine at the 2-position by CH2C12 or CH2Br2299. 

Yoshida and coworkers47 reported that they readily oxidized bromide and chloride anions into positive halogens with p-nitrobenzenesulfonyl peroxide (equation 26). They found that oxyhalogenated products were formed from the reaction of these positive halogens with olefins, and proposed epihalonium ion intermediates which, in turn, were trapped by oxygen nucleophiles inter- or intramolecularly to afford the oxyhalogenated products (equation 27). 

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