Tetrafluoroethylene reaction with

The reactions with IF are more amenable to control giving good yields of identifiable products and lower losses from oxidative fragmentation. The reaction of IF and iodine with tetrafluoroethylene produces the telomer perfluoroethyl iodide [354-64-3] ia yields that exceed 98% based on... 

Reactions with Organic Compounds. Tetrafluoroethylene and OF2 react spontaneously to form C2F and COF2. Ethylene and OF2 may react explosively, but under controlled conditions monofluoroethane and 1,2-difluoroethane can be recovered (33). Benzene is oxidized to quinone and hydroquinone by OF2. Methanol and ethanol are oxidized at room temperature (4). Organic amines are extensively degraded by OF2 at room temperature, but primary aHphatic amines in a fluorocarbon solvent at —42°C are smoothly oxidized to the corresponding nitroso compounds (34). 

Tetrafluoroethylene Oxide TFEO has only been prepared by a process employing oxygen or ozone because of its extreme reactivity with ionic reagents. This reactivity may best be illustrated by its low temperature reaction with the weak nucleophile, dimethyl ether, to give either of two products (47) (eq. 10). 

Preparation. The preparation of tetrafluoroethylene has been described previously. Perfluorovinyl ethers (4—7) are prepared by the following steps. Hexafluoropropylene [116-15-4] (HEP) is oxidized to an epoxide HEPO [428-59-1] (5) which, on reaction with perfluorinated acyl fluorides, gives an alkoxyacyl fluoride. 

Perfluoro-2 (1 ethyl 1 methylpropyl)-3-methyl-l-pentene, the major hex-amer of tetrafluoroethylene, reacts with sodium methoxide to yield an ester, whereas a stable crowded ketene is formed by reaction with sodium hydroxide [2d] (equation 23)... 

Fluorinated polymers, especially polytetrafluoroethylene (PTFE) and copolymers of tetrafluoroethylene (TFE) with hexafluoropropylene (HFP) and perfluorinated alkyl vinyl ethers (PFAVE) as well as other fluorine-containing polymers are well known as materials with unique inertness. However, fluorinated polymers with functional groups are of much more interest because they combine the merits of pefluorinated materials and functional polymers (the terms functional monomer/ polymer will be used in this chapter to mean monomer/polymer containing functional groups, respectively). Such materials can be used, e.g., as ion exchange membranes for chlorine-alkali and fuel cells, gas separation membranes, solid polymeric superacid catalysts and polymeric reagents for various organic reactions, and chemical sensors. Of course, fully fluorinated materials are exceptionally inert, but at the same time are the most complicated to produce. 

Preference for reaction with the unlike monomer occurs when ri is less than 1. When r and T2 are approximately equal to 1, the conditions are said to be ideal, with a random (not alternating) copolymer produced, in accordance with the Wall equation. Thus, a random copolymer (ideal copolymer) would be produced when chlorotrifluoroethylene is copolymerized with tetrafluoroethylene (Table 7.1). 

The reaction of the tetrafluoroethylene trimer with seven equivalents of dry triethylamine and three equivalents of cyclohexylamine in dry ether gave l-cyclohexyl-2-trifluoromethyl-3-(2,2,2-trifluoroethylidene)cyclohexyli-mino-4-N-cyclohexylimino-2-azete (80JCS(P 1)1551). 

Note that the reaction of the tetrafluoroethylene pentamer with the alkoxide anion at low temperatures (—30 to —40°C) yields the kinetically controlled product, whereas the thermodynamically controlled product is obtained at 20 °C (94JFC(67)95, 88CJC446). 

The reaction of the tetrafluoroethylene trimer with phenylhydrazine in the presence of three equivalents of triethylamine leads to the formation of E and Z octafluoro-3-trifluoromethyl-4-(N-phenylhydrazino)pent-3-enes, which further undergo intramolecular cyclization into 3,4,5-tris(trifluoro-methyl)-1 -phenylpyrazole 63 (98JFC(88)169). 

The reaction of the tetrafluoroethylene trimer with one equivalent of diethylmalonate and two equivalents of sodium hydride in dry ether gives a mixture of 5-carboethoxy-6-ethoxy-2,3,4-tris(trifluoromethyl)-2-pyran and 5-carboethoxy-6-ethoxy-2,3,4-tris(trifluoromethyl)-4-pyran in a 2.1 1 ratio with a total yield of 71% (98JFC(88)169). 

The reaction of the tetrafluoroethylene trimer with aniline or 2,5-dimethoxy-aniline forms 2-trifluoromethyl-3-(l-N-phenylimino-2,2,2-trifluoroethyl)-4-(N-phenylamino)quinoline 113 (whose structure was confirmed by X-ray analysis) and 2-trifluoromethyl-3-pentafluoroethyl-4-(N-2,5-dimethoxyphe-nyl)-amino-5,8-dimethoxyquinoline 114 with yields 80 and 75%, respectively (98JFC(88)169). 

Tetrafluoroethylene was the only fluorine-containing product obtained from attempted coupling reactions with 1,2-dibromo- and 1,2-diiodotetrafluoroethane, and dibromodifluoromethane, perhaps via unstable copper compounds 200). 

Preparation of nitronitroso dimers fiom a variety of straight chain alkenes has been patented. ° The reactions of nitric oxide with alkenes are extremely complex (e.g. isobutylene) and are rarely useful. Perfluoroalkenes add nitric oxide at room temperature in the ds tetrafluoroethylene gives ONCF2CF2NO (68%) the reaction with peifluoropropene is more complex. ... 

SAFETY PROFILE A poison. Probably an irritant to the eyes, skin, and mucous membranes. A powerful oxidizer. Explosive reaction with benzene (above 50°C), diethyl-aminotrimethyl silane, dimethyl sulfoxide, limonene + tetrafluoroethylene (polymerization), potassium, molten sodium, tetraio-doethylene. Reaction with organic... 

The C(F)2(CF2)2 group increment allows evaluation of the strain energy in octa-fluorocyclobutane. There are three published experimental studies providing AHf (g) data for this compound The first value (taken from Pedley and Rylance s thermochemical archives ) is — 368.7 kcal mol" and is based upon reaction with sodium while the O Neal and Benson value ( — 367.8 kcal mol" if one employs the archival value for C2F4) is based upon the experimental equilibrium with tetrafluoroethylene. The third value, based upon combustion measurements, is - 365.2 kcal mol" if one employs archival values for the products. The strain energy is thus between 14.5 and 18 kcal mol" some 8.5-12 kcal mol" lower than in the parent hydrocarbon. Why is this value low One explanation may follow recent work by Wiberg . He concludes that a large part of the strain in cyclobutane is due to repulsion between non-bonded carbons and... 

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