Perfluoro-n-pentane

As indicated earlier, vicinal F-F coupling constants in perfluoroalka-nes are often very small, virtually negligible in comparison to longer range couplings, as is the case for perfluoro-n-pentane above where the four-bond F-F coupling is 10.2 Hz. 

Synonyms Dodecafluoropentane Pentane, dodecafluoro- Perfluoro-n-pentane... 

ManuUDistrib. ABCR Apollo Scientific Trade Names PF-5050 Perfluoro-n-pentane. See Perfluoropentane Perfluoropolyether carboxylic acid... 

Polyperfluoroalkyl substitution greatly stabilizes both Dewar-pyridine and azaprismane valence isomers. Irradiation of pentakis(pentafluoroethyl)pyridme 134 in perfluoro-n-pentane with Hght of A, >... 

Further (c/. Vol. 1, p. 89) Russian work on fluoroalkenylcarbaboranes has been reported (see p. 60), fluoroalkylborates have been synthesized via reaction of hexafluoroacetone and related ketones with boron halides, organoboron halides, or alkylthioboranes (see p. 257), and from perfluoro-alkyl hypochlorites (see p. 264), CFj-S—B compounds have been prepared (see p. 270), and conductivity studies on the complex acid HBfOaC CFj) and its caesium salt have been described. Attempts to isolate the tristri-fluoroacetate B(02C CF3)a from products of the reaction systems B(OH)3-(CFs CO) , BCl3-(CF9 CO)jO-n-pentane, and BCl3-CF3-C02H-n-pentane have yielded only I(CF3 C0s)2B]20 or [(CF3 C02)2B]30-B(02C CF3)3 mixtures (c/. ref. 58). 

Recently the direct synthesis and the stability of perfluoro-w-propyl-lithium has been the subject of a careful study (8). Although heptafluoro-propyl iodide does not react with lithium metal in pentane or diethyl ether at temperatures between —50° and 20° C, a vigorous reaction occurs at —74° C between the iodide and lithium containing 2% sodium when diethyl ether is the solvent. Among the reaction products are hexafluoropropene, fluorine-containii pol)rmers, andatraceof heptafluoropropane. Formation of heptafluoropropane can be understood in terms of hydrogen abstraction from the solvent by perfluoro-n-propyllithium, while hexafluoropropene could form by the reactions,... 

N-Cyclohex-l-enylpyrrolidine (9 g 0 06 mol) was dissolved in pentane with A -ethyldiisopropylamine (7.8 g 0.06 mol). Perfluorohexyl iodide (13.4 g, 0.03 mol) IS added to the solution. Aprecipitate of A-ethyldiisopropylamine hydroiodide IS formed instantly After 3 h, the precipitate is filtered off, and the solution is evaporated The crude liquid is hydrolyzed with 6 mL of 40% sulfuric acid The mixture is stirred for 3 h and extracted with ether. The ether layer is neutralized with aqueous sodium hydrogen carbonate, washed with water, and dried over magnesium sulfate. The solvent is evaporated, and the residue is distilled. A second distillation with a spinning-band column yields 7 9 g (63%) of pure 2-(perfluoro-hexyl)cyclohexanone (bp, 71 -73 °C at 0 4 mm of Hg). 

Perfluoro-(2,5-dimethyl-l-oxa-2,5-diazacyclopentane) (57) decomposes slowly at room temperature in the absence of light to give 1 mol. equiv. of perfluoro-2-azapropene and a quantitative yield of a gum possessing an elemental analysis and F n.m.r. spectral characteristics consistent with the polymer [N(CF3)-0-CF2]n presumably homolytlc ring fission at an N—O bond is followed by j3-scission of the resultant biradical (59) [see Scheme 42 . (CF3)2N-0-N(CF3)2 + heat (CFs)2N-0 + (CFs)2N ->-(CF3)2N-N(CF3)2]. Flow pyrolysis of the diazacyclo-pentane at 150—200 °C and ca. 1 mmHg pressure in platinum yields trifluoronitro-somethane, carbonyl fluoride, perfluoro-2-azaiM opene, and traces of a yellow gas that possesses i.r. spectral characteristics identical with those reported for a... 

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