F Fluoroethylene

The way in which these factors operate to produce Type III isotherms is best appreciated by reference to actual examples. Perhaps the most straightforward case is given by organic high polymers (e.g. polytetra-fluoroethylene, polyethylene, polymethylmethacrylate or polyacrylonitrile) which give rise to well defined Type III isotherms with water or with alkanes, in consequence of the weak dispersion interactions (Fig. S.2). In some cases the isotherms have been measured at several temperatures so that (f could be calculated in Fig. 5.2(c) the value is initially somewhat below the molar enthalpy of condensation and rises to qi as adsorption proceeds. In Fig. 5.2(d) the higher initial values of q" are ascribed to surface heterogeneity. 

Methylpentene polymer, a light plastic, has a crystalline melting point of 464 retention up to 392° F, transparency of 92%, and electrical properties similar to fluoroethylene. Its impact strength is greater than polystyrene and polymethyl methacr resistant to alkalies, weak acids, and non-chlorinated solvents. It may be injection m< implements for food packaging and preparation, medical care, and non-stick coating ... 

The behavior of strained,/Zuorimiret/ methylenecyelopropanes depends upon the position and level of fluorination [34], l-(Difluoromethylene)cyclopropane is much like tetrafluoroethylene in its preference for [2+2] cycloaddition (equation 37), but Its 2,2-difluoro isomer favors [4+2] cycloadditions (equation 38). Perfluoromethylenecyclopropane is an exceptionally reactive dienophile but does not undergo [2+2] cycloadditions, possibly because of stenc reasons [34, 45] Cycloadditions involving most possible combinations of simple fluoroalkenes and alkenes or alkynes have been tried [85], but kinetic activation enthalpies (A/f j for only the dimerizations of tetrafluoroethylene (22 6-23 5 kcal/mol), chlorotri-fluoroethylene (23 6 kcal/mol), and perfluoropropene (31.6 kcal/mol) and the cycloaddition between chlorotnfluoroethylene and perfluoropropene (25.5 kcal/mol) have been determined accurately [97, 98] Some cycloadditions involving more functionalized alkenes are listed in Table 5 [99. 100, 101, 102, 103]... 

A complete database of F-NMR information on 66 fluorinated etlianes and ethylenes of the formula CjHjjCl F is available on floppy disk through Project Seraphim [22]. Table 2 presents only (lie nine nonchlorinated fluoroethanes, and Table 3 presents the six nonchlorinated fluoroethylenes from this more extensive list. 

Hutton, H. M., Schaefer, T. Solvent Effects on the Proton Chemical Shift and H—H, H-F Coupling Constants in 1-Chloro-l-fluoroethylene. Reaction Field and Dispersion Interactions. Can. J. Chem. 45, 1111 (1967). 

Fluoroethylene ozonide, 0752 /rMaleic anhydride ozonide, 1406 f 2-Methyl-1,3-butadiene, Ozone, 1893 3-Methyl-l,2,4-trioxolane, 1235 trans-2-Pentene ozonide, 1982... 

Numerous haloallenes are known, but the perhaloallenes of the type XjC - C CXj were unknown until a study at the Univ of Calif, LA (Ref 5) was undertaken as part of the US Dept of the Army Contract DA-04-495 ORD-527. It is expected that compds such as tetrafluorocdlene, F,C C CF2 will be of interest as monomers for both homopolymerization and copolymerization studies and for the prepn of materials similar to Teflon which is the homopolymer of tetra-fluoroethylene F2C CF2. This study is being continued as of 1958 Refs l)Beil 1, 248,(107),[223] 19221... 

Fluoro-1,2,4-trioxolane, see Fluoroethylene ozonide, 0749 Fluoroxymethane, see Methyl hypofluorite, 0441 f Formaldehyde, 0415... 

Vinyldiazomethane, see 3-Diazopropene, 1132a Vinylene carbonate, see l,3-Dioxol-4-en-2-one, 1084 f Vinyl fluoride, see Fluoroethylene, 0744 f Vinylidene chloride, see 1,1-Dichloroethylene, 0691 f Vinylidene fluoride, see 1,1-Difluoroethylene, 0696 Vinyllithium, 0754... 

The first member of this family - vinylidene fluoride - readily adds fluoro-sulfonic acid, even in the absence of the catalyst, and it is nitrofluorinated by a HNO3/HF mixture six times faster than CFH=CF2 [15] however, HF/HS03F superacid does not react at ambient temperature with C1CF=CF2 or CF2=CF2. These two olefins show a similar reactivity in electrophilic reactions. Interaction of polyfluorinated propylenes CF2=CXCF3 (X=H,F) with trifluoro- and tetra-fluoroethylenes proceeds at room temperature in the presence of a Lewis acid catalyst to give the corresponding polyfluoropentenes-2 ... 

Introduction of nitro and fluorosulfonoxy groups can be carried out by reaction of ionic 02N0S02F with fluoroolefins [8,116-118]. Nitronium fluorosulfa-te is not as active as halogen fluorosulfates addition to CH2=CF2 and CFH=CF2 proceeds only at ambient temperature [117]. Reaction with TFE and chloro-fluoroethylene proceeds at a noticeable rate at temperature above 50 °C, while addition to 2-H-F-propene only at temperatures higher than 120 °C [117] ... 

Reactivity of nitrosonium fluorosulfate and trifluoromethansulfonate 0N0S02X (X=F, CF3) is similar to that of nitronium fluorosulfate, although they are less active than the latter. Reaction, which occurs only with fluoroethylenes and perfluorinated vinyl ethers [ 119 -121 ], is of an electrophilic nature it results in low to moderate yields of nitrosoalkyl compounds when the olefin has a limited contact time with the reaction mixture ... 

The first example of electrophilic condensation of polyfluorinated olefins with fluoroethylenes was reported in 1975 [150]. Reaction of HFP and TFE in the presence of SbF5 catalyst produces F-pentene-2, mostly the trans-isomer ... 

Reaction of polyfluorinated dienes with TFE resembles the reaction of polyfluoropropynes with fluoroethylenes. Polyfluorinated dienes react with TFE at ambient temperature in the presence of SbF5 catalyst [159].F-Heptadiene-2,4 (65) was obtained in 77% yield in reaction of F-pentadiene-1,3 and TFE along with small amounts of F-nonadiene-3,5. F-Hexadiene-2,4 reacts with TFE at 50 °C to give a mixture of isomeric octadienes 66 a, b ... 

The large C-F bond moment in fluoroethylene, shown in Figure 4.18(g), dominates the dipole moment, which must lie in the molecular plane, but its direction in that plane will depend on the effects of the other parts of the molecule with the result that it will not lie exactly along the C-F bond. 

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