Fluorine oxidation state

This ability to bring out high oxidation states is exhibited also by fluorine it is to be attributed to the high electronegativities of oxygen and fluorine.)... 

Chlorine reacts with most elements, both metals and non-metals except carbon, oxygen and nitrogen, forming chlorides. Sometimes the reaction is catalysed by a trace of water (such as in the case of copper and zinc). If the element attacked exhibits several oxidation states, chlorine, like fluorine, forms compounds of high oxidation state, for example iron forms iron(III) chloride and tin forms tin(IV) chloride. Phosphorus, however, forms first the trichloride, PCI3, and (if excess chlorine is present) the pentachloride PCI5. 

Bromine has a lower electron affinity and electrode potential than chlorine but is still a very reactive element. It combines violently with alkali metals and reacts spontaneously with phosphorus, arsenic and antimony. When heated it reacts with many other elements, including gold, but it does not attack platinum, and silver forms a protective film of silver bromide. Because of the strong oxidising properties, bromine, like fluorine and chlorine, tends to form compounds with the electropositive element in a high oxidation state. 

Also, in anhydrous conditions, silver reacts with fluorine and forms silver difluoride AgFj and cobalt gives cobalt(III) fluoride, C0F3, these metals showing higher oxidation states than is usual in their simple salts. 

Halogens can act as ligands and are commonly found in complex ions the ability of fluorine to form stable complex ions with elements in high oxidation states has already been discussed (p. 316). However, the chlorides of silver, lead(Il) and mercury(l) are worthy of note. These chlorides are insoluble in water and used as a test for the metal, but all dissolve in concentrated hydrochloric acid when the complex chlorides are produced, i.e. [AgCl2] , [PbC ] and [Hg Clj]", in the latter case the mercury(I) chloride having also disproportionated. 

Elements exhibit their highest oxidation state when combined with fluorine. 

As already noted, the simple salts in this oxidation state are powerful oxidising agents and oxidise water. Since, also, Co(III) would oxidise any halide except fluoride to halogen, the only simple halide salt is C0F3. Cobalt(lll) Jluoride, obtained by reaction of fluorine with cobalt(II) fluoride it is a useful fluorinating agent. 

Fluorine is the most electronegative element and thus can oxidize many other elements to their highest oxidation state. The small size of the fluorine atom facihtates the arrangement of a large number of fluorines around an atom of another element. These properties of high oxidation potential and small size allow the formation of many simple and complex fluorides in which the other elements are at their highest oxidation states. 

The only example of xenon in a fractional oxidation state, +, is the bright emerald green paramagnetic dixenon cation, Xe [12185-20-5]. Mixtures of xenon and fluorine gases react spontaneously with tiquid antimony pentafluoride in the dark to form solutions of XeF+ Sb2 F, in which Xe is formed as an iatermediate product that is subsequently oxidized by fluorine to the XeF+ cation (83). Spectroscopic studies have shown that xenon is oxidized at room temperature by solutions of XeF+ ia SbF solvent to give the XE cation (84). 

In the diaziridine field many compounds are known bearing N-YL, A/-alkyl and A-acyl groups, but here no dramatic changes in reactivity are caused by A-substituents. N-Aryldiaziridines are underrepresented. The ring carbon is in the oxidation state of a carbonyl compound or, in the diaziridinones (5) and the diaziridinimines (6) that of carbonic acid. In single cases, diaziridine carbon bears chlorine or fluorine. 

Fluorine and nitrogen may be added to olefins with the nitrogen in different oxidation states Fluorine and a nilro group are added by reaction of an olefin with nitryl fluoride [131], nitronium tetrafluoroborate [195] (equation 32), or a combination of nitric acid and hydrogen fluoride [131, 196] (equation 33)... 

Oxidation states above 4-3 are attained only with difficulty and are confined mainly to AuFj, mentioned above, together with salts of the octahedral anion [AuF ]", and to Cs2[Cu" F6], prepared by fluorinating CsCuCl3 at high temperature and pressure. 

The halogens, except fluorine, can be oxidized to positive oxidation states. Most commonly you will encounter these positive oxidation states in a set of compounds called halogen oxyacids and their ions. 

The designation of hard acids is not restricted to metal cations. For example, in BF3 the small boron atom in its +3 oxidation state is bonded to three highly electronegative fluorine atoms. All the B—F bonds are polarized away from a boron center that is already electron-deficient. Boron trifiuoride is a hard Lewis acid. 

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