168087-02-3Relevant academic research and scientific papers
An extraordinarily rapid polymerization of vinylpentafluorocyclopropane: Highly stereo- and regioselective synthesis of unsaturated fluoropolymers
Yang, Zhen-Yu
, p. 870 - 871 (2003)
Vinylpentafluorocyclopropane 1 was prepared from the reaction of 1,1,2-trifluoro-4-bromobutene and hexafluoropropylene oxide at 190 °C, following by treatment with KOH. 1 is stable at low temperature (-40 °C) for 7 years, but it rearranged readily to 2,3,3,4,4-pentafluorocyclopentene-1, 2, at above 80 °C (Ea = 28.7 kcal/mol). Under radical conditions, 1 extraordinarily rapidly polymerizes to give highly crystalline Z-fluoropolyolefin (CF2CF2CF=CHCH2)n, 3, which is very useful for cross-linking and grafting but difficult to obtain by other means. The stereochemistry of 3 was further confirmed by radical addition of iodine to 1 to form Z-ICF2CF2CF=CHCH2I, 4, exclusively. The rapid polymerization with high stereoselectivity and regioselectivity could be rationalized by effects of a favorable polar transition state of a high ring strain and electron-deficient pentafluorocyclopropyl and a relative electron-rich double bond of 1. Copyright
1-Vinyl-1,2,2,3,3-pentafluorocyclopropane: An extraordinarily rapid vinylcyclopropane rearrangement
Smart, Bruce E,Krusic, Paul J,Roe, D.Christopher,Yang, Zhen-Yu
, p. 199 - 205 (2002)
The synthesis of 1-vinyl-1,2,2,3,3-pentafluorocyclopropane (1) and the kinetics of its thermal, unimolecular rearrangement to 1,4,4,5,5-pentafluorocyclopentene (2) are reported. Kinetic data were obtained by gas-phase 19FNMR at 80-120 °C, and the activation parameters for the rearrangement of 1 to 2 are: ΔG?(100 °C) = 28.7 kcal/mol, ΔH? = 26.7 kcal/mol, and ΔS? = -5.5 eu (log A = 12.7, Ea = 28.4 kcal/mol). Vinyl(pentafluorocyclopropane) (1) with a half-life of only 38 min at 110 °C, is one of the most thermally labile vinylcyclopropanes known. The isomeric E- and Z-1-propenyl-1,2,2,3,3-pentafluorocyclopropanes (3) similarly have relatively low activation parameters: ΔG?(E) ? 28.5 kcal/mol and ΔG?(Z) ? 31.1 kcal/mol. A favorable, polar biradical transition state for rearrangement is proposed to account the exceptional reactivity of these alkenyl pentafluorocyclopropanes.
Polymers of vinyl(perfluorocyclopropane)
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, (2008/06/13)
Disclosed herein are polymers made by free radically polymerizing the novel compound vinyl(perfluorocyclopropane), and optionally other monomers to form copolymers. The repeat unit formed by vinyl(perfluorocyclopropane) contains an olefinic bond, making it particularly useful as a grafting and/or crosslinking site.
