Fluorine perchlorate addition

The highest yield of perchloryl fluoride (97%) was achieved with a mixture of fluorosulfonic acid and SbFj as fluorinating medium. Potassium, sodium, lithium, magnesium, barium, calcium, and silver perchlorates and perchloric acid itself undergo the reaction. Commercial reagents are used and their additional puriflcation is not necessary unlike all the previous methods the preparation of perchloryl fluoride by this method can be carried out at room temperature. At high temperature (100°-135°C) the reaction time is 1-10 min in all, which allows the process to be carried out continuously in a packed column. The purity of product obtained after the usual puriflcation reaches 98% and over air and carbon dioxide are present as trace impurities 23). 

Ref 93). Extreme caution should be used in reducing any fluorinated compound with LiAlH4. Violent reactions have been observed with two different fluoro compounds (Refs 76 95). Excess trimethyl amine, NMes, reacts with an ethereal /solution of LiAlH4 in vacuo at -SO t to form a white addition compound which is slightly soluble in ether, insoluble in benzene, and spontaneously flammable in air (Ref 98a) Magnesium perchlorate may be used as a drying... 

Both perchloric and periodic (per-I-od ic) acids can be prepared from the electrolytic oxidation of the corresponding halate followed by the addition of a strong acid. The preparation of perbromic acid proved more difficult and was not accomplished until 1968 (see Problem 18.52). The best route (but still difficult and low yielding) involves the oxidation of bromate to perbromate with fluorine gas, as shown in Equation (18.44) ... 

Sodium peroxide fusion in a metal bomb has also been used to decompose polymers prior to the determination of down to 50 ppm sulphur. In the procedure described in Method 81 sodium is removed from the fusion product by means of a cation exchange resin and the sulphate is determined by titration with standardised 0.005M barium perchlorate. Chlorine, fluorine and nitrogen in amounts up to 2 mg. in the sample are without serious effect on the determination of sulphur. The effect of larger amounts of fluorine can be suppressed by the addition of boric acid. 

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