Oxyhalogen Compounds

addition of HOBr can eliminate the induction period for oscillations in a Belousov-Zhabotinskii system. However, in a solution saturated with air, the initial addition of HOBr causes a train of only a few oscillations. Oscillating reactions have been examined very extensively in recent issues of the Journal of 

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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... 

General Properties of Chromium Compound.s—Chromium and Hydrogen— Halogen and Oxyhalogen Compounds—Oxides and Hydroxide.s— Chromites—Chromic Acid—Chromates, Dichromates, and Polyohromates— Perohromio Acid and Perehromate.s—Compounds with Sulphur, Selenium, and Tellurium. 

General Properties of Molybdenum Compounds—Molybdenum and Hydi-ogcn— Halogen and Oxyhalogen Compounds—Oxides and Hydroxides—Molybdio Acid, Molybdates, and Polymolybdates—Permolybdio Acid and Permolyb-dates—Compounds with Sulphur, Selenium, and Chromium. 

There is no evidence that fluorine ever exists in a positive oxidation state. This is reasonable in view of the fact that there is no element that is more electronegative and capable of taking electron density away from it.51 Certainly the oxygen compounds of fluorine come the closest to achieving a positive charge on fluorine, and since their chemistry is in some ways comparable to that of the other oxyhalogen compounds it is convenient to include these compounds here. 

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. 

Noncomplementary redox reactions between halogen and oxyhalogen species often exhibit complex kinetic patterns which can be understood in terms of multistep kinetic models. The corresponding mechanisms are centered on the formation and subsequent reactions of reactive intermediates such as XO2 (X = halogen) and related compounds. Stopped-flow techniques can be used to provide insights into the redox reactions. Several examples of redox reaction are also described in Section 3.5. 

Studies on the conditions of the reaction have been made using simple compounds as model substances, A comparison of thirty-nine metallic chlorides shows aluminum chloride to be the most effective in the preparation of p-methylacetophenone. Optimum yields result when the molar ratios of aluminum chloride to anhydride, acyl chloride, and acid are 3.3, 1,0, and 2.5, respectively. Halogen and oxyhalogen carriers are not helpful. Inconsistent yields in the Friedel-Crafts reaction have been attributed to the presence of ferric chloride or moisture in the aluminum chloride Catalyst. Prolonged heating causes condensation of the ketone product. 

P-24 - Oxyhalogenation of aromatic compounds in presence of KCl or KBr and H2O2 over zeolites... 

According to [65], the inhibition of a flame is caused by reactions with the participation of oxygen atoms and the formation of intermediate compounds, oxyhalogens ... 

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