CoF3 Cobalt

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 CoF3, Cobalt(lll) fluoride, obtained by reaction of fluorine with cobalt(II) fluoride it is a useful fluorinating agent. 

Co(en)2(N02)2]N03 cis- and trans-Dinitrobis(ethylenediamine)co-balt(III) nitrate, 4 176, 177 [Co(en)3]Cl3 Tris(ethylenediamine)-cobalt(III) chloride, 2 221 CoF3 Cobalt(III) fluoride, 3 175 [Co NH(C5H4N)21C12] Dichloro-(di-2-pyridylamine)cobalt (II), 6 184... 

CoF3 COBALT TRIFLUORIDE 541 CrNa02 CHROMIUM SODIUM DIOXIDE 577... 

Also, in anhydrous conditions, silver reacts with fluorine and forms silver difluoride AgF2 and cobalt gives cobalt(III) fluoride, CoF3, these metals showing higher oxidation states than is usual in their simple salts. 

Cobalt is a bluish silvery metal, exhibits ferromagnetism, and can exist in more than one crystal form it is used in alloys for special purposes. Chemically it is somewhat similar to iron when heated in air it gives the oxides Co304 and CoO, but it is less readily attacked by dilute acids. With halogens, the cobalt(II) halides are formed, except that with fluorine the (III) fluoride, CoF3, is obtained. 

Electrolytic oxidation of cobalt(II) fluoride in 40% hydrofluoric acid yields hydrated cobalt(III) fluoride, CoF3 3.5H20 (3.5 is the stoichiometric amount of water per C0F3 molecule in the crystal lattice). 

Cobalt Trifluoride, CoF3, mw 115.94 lt-brn, free-flowing pdr sp gr 3.88 reacts with w to form bk ppt of cobaltic hydroxide unstable in moist air. Can be prepd from Co C1FS (Ref 1)... 

The action of fluorine or other fluorinating agents on cobalt halides at 300 to 400°C gives dark brown CoF3, commonly used as a fluorinating agent. It is reduced by water. 

Cobalt(III) forms few simple salts, but the green hydrated fluoride CoF3-3.5H20 and the blue hydrated sulfate Co2(S04)3-18H20 separate on electrolytic oxidation... 

Cobalt tetrafluoride has been detected only in the gas phase [68]. It was synthesized by the reaction between CoF3 and excess of TbF4 in a Knudsen-cell and detected by mass spectrometry. The reaction was performed at temperatures between 600 and 680 K. Under these reaction conditions, peaks of CoF+ (0 < n < 3), F, and CoF were found. The peak for CoFJ, mlz = 135 gmol-1 was present only when the C0F3 and TbF4 mixture was heated to 600 K. The bond dissociation enthalpy for... 

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