General Procedure for Substituting Hydrogens with Fluorine

General Procedure for Substituting Hydrogens with Fluorine 

Mixtures of 25-30% fluorine diluted with nitrogen were used in this work. The gas mixtures were prepared in a secondary container. The appropriate polyether was dissolved either in perfluoro-2-butyl-THF (FC-75) or in Krytox GPL 100 (a fluorinated oil), which also contained about 5 g of pulverized NaF to absorb the relased HE The reaction mixture was cooled to - 10°C, stirred with the aid of a vibromixer and irradiated with a 450-W medium-pressure mercury lamp. A stream of fluorine in nitrogen (ca. 140 ml/min) was passed into the mixture such that the temperature did not rise above +10°C. The reaction was stopped after 200 mmol of fluorine had been passed through. The mixture was poured into water and the organic layer was washed with sodium bicarbonate solution. The water layer was extracted twice with CFCL. The combined fluorocarbon fractions were washed with water, dried with MgS04, and filtered, and the solvent was removed under reduced pressure. 

The oligometric mixture (2.6 g) was reacted as above using Krytox GPL 100 as solvent. Upon completion of the reaction, the Krytox was removed by distillation and the reaction mixture was left at 125°C under 2 mm Hg for 4 h. The residue (2.05g, 78% yield) showed no detectable protons in the H-NMR. The 19F-NMR is characteristic of the repeating unit -82 to -91.5 (m, 13F), -131.5 (m, 2F), -147.3ppm (m, IF). 

Billmeyer, Jr. in Textbook of Polymer Science, John Wiley and Sons, New York (1984), Ch. 2. 

BRUNO AMEDURI, BERNARD BOUTEVIN, GERARDO CAPORICCIO, FRANCINE GUIDA-PIETRASANTA, ABDELLATIF MANSERI, and AMEDEE RATSIMIHETY 

A cold solution (- 10°C) of 3.66 g ofthe cyclic dimer 9 in perfluoro-2-butyl-THF (FC-75) was prepared. NaF (5 g) was added and the reaction was performed as described above. The main product was distilled at 50°C/0.25 mmHg, using a Kugelrohr and was identified as perfluorinated cyclic dimer 13, 3.4 g (82% yield). No protons were detectable in the H-NMR. T-NMR (THF-(S g/CFCl3, 470.5 MHz) -80.94 (apparent 9.8 Hz, CFj), -81-08 (apparent 

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General Procedure for Substituting Hydrogens with Fluorine 64... 

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