Pentafluorides Subject

Electrolytic reduction of 4-cyclooctenone leads smoothly in 64 % yield to cis-bicyclo[3.3.0]octan-l-ol.106) The thermolysis of octachlorocyclooctatetraene produces perchlorinated bicyclo[3.3.0]octatrienes,107,108) several of which have been examined in detail by X-ray structural methods.109) The 1,3,5,7-tetramethyl-cyclooctatetraene dication (57), generated by oxidation of the neutral hydrocarbon with antimony pentafluoride in S02C1F at —78 °C and below, is subject to dis-rotatory cyclization above — 60°.1 °) The latter step does not follow orbital sym-... 

It was assumed that OsO,F, would be colourless and diamagnetic and phjrsically similar to OsOF, and OsF,. The infrared spectra of osmium oxide pentafluoride samples taken from a variety of preparations were identical with one another. The entire product from one oxyfluorination of osmium metal was subjected to infrared examination. The bulk of the sample in a Monel trap, was isolated from the gas cell by a Hoke valve. After each vapour sample had been scanned it was discarded and a new sample of vapour admitted. This was repeated exhaustively. All the spectra were interpretable in terms of OsF OsOF OsO and traces of HF, CF, SiF and CO,. Two independent magnetic measurements on samples of OsOF one from an oxjrfluorination of the metal and the other from the fluorination of the dioxide gave magnetic susceptibility values equal within the usual experimental uncertainty. Furthermore the magnitude of the susceptibility was consistent with pure OsOF,. 

The fluorine content thus is obtained entirely from low-cost hydrogen fluoride. This reaction, because of its potential large-scale utility, has therefore been the subject of a number of investigations. Ferris (28) has examined the side reactions and thermodynamics of the oxidation in the temperature range 600-900°. In addition to the expected products UFe and UO2F2, Ferris observed the formation of uranium pentafluoride. Its formation was postulated to be the result of a side reaction between UF and UF4. Detailed experiments indicated also that the reaction... 

Perfluoralkoxy will be attacked by certain halogenated complexes containing fluorine. This includes chlorine trifluoride, bromine trifluoride, iodine pentafluoride, and fluorine. It is also subject to attack by such metals as sodium or potassium, particularly in their molten states. Refer to Table 2.24 for the compatibility of PFA with selected corrodents. Reference [1] provides a more detained listing. PFA has excellent weatherability and is not subject to UV degradation. 

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