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Hexafluorocyclobutene
Hexafluorocyclobutene is the organofluorine compound with the formula (CF2)2(CF)2. A colorless gas, it is a precursor to a variety of compounds, including squaric acid. Hexafluorocyclobutene is prepared in two steps from chlorotrifluoroethylene. The thermal dimerization gives 1,2-dichloro-1,2,3,3,4,4-hexafluorocyclobutane. Dechlorination of the latter gives hexafluorocyclobutene: :C4F6Cl2 + Zn -> C4F6 + ZnCl2 Safety Reminiscent of perfluoroisobutene, hexafluorocyclobutene is quite toxic with an LD = 6000 mg/min/m−3 (mice).{{cite book , doi=10.1016/B978-008043405-6/50040-2, chapter=Highly-toxic fluorine compounds, title=Fluorine Chemistry at the Millennium, year=2000, last1=Timperley, first1=Christopher M., pages=499–538, isbn=9780080434056 See also *Hexafluoro-2-butyne *Hexafluorobutadiene Hexafluorobutadiene is an organofluorine compound with the formula (CF2=CF)2. A colorless gas, it has attracted attention as an etchant in microelectronics. It is the perfluor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorotrifluoroethylene
Chlorotrifluoroethylene (CTFE) is a chlorofluorocarbon with chemical formula CFCl=CF2. It is commonly used as a refrigerant in cryogenic applications. CTFE has a carbon-carbon double bond and so can be polymerized to form polychlorotrifluoroethylene or copolymerized to produce the plastic ECTFE. PCTFE has the trade name Neoflon PCTFE from Daikin Industries in Japan, and it used to be produced under the trade name Kel-F from 3M Corporation in Minnesota. Production and reactions Chlorotrifluoroethylene is produced commercially by the dechlorination of 1,1,2-trichloro-1,2,2-trifluoroethane with zinc: :CFCl2-CF2Cl + Zn → CClF=CF2 + ZnCl2 In 2012, an estimated 1–10 million pounds were produced commercially in the United States. The thermal dimerization of chlorotrifluoroethylene gives 1,2-dichloro-1,2,3,3,4,4-hexafluorocyclobutane. Dichlorination of the latter gives hexafluorocyclobutene Hexafluorocyclobutene is the organofluorine compound with the formula (CF2)2(CF)2. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organofluorine Compound
Organofluorine chemistry describes the chemistry of the organofluorines, organic compounds that contain the carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from oil and water repellents to pharmaceuticals, refrigerants, and reagents in catalysis. In addition to these applications, some organofluorine compounds are pollutants because of their contributions to ozone depletion, global warming, bioaccumulation, and toxicity. The area of organofluorine chemistry often requires special techniques associated with the handling of fluorinating agents. The carbon–fluorine bond Fluorine has several distinctive differences from all other substituents encountered in organic molecules. As a result, the physical and chemical properties of organofluorines can be distinctive in comparison to other organohalogens. # The carbon–fluorine bond is one of the strongest in organic chemistry (an average bond energy around 480 kJ/molKirsch, Peer ''Modern fluoroorga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squaric Acid
Squaric acid, also called quadratic acid because its four carbon atoms approximately form a square, is a diprotic organic acid with the chemical formula C4O2(OH)2. The conjugate base of squaric acid is the hydrogensquarate anion ; and the conjugate base of the hydrogensquarate anion is the divalent squarate anion . This is one of the oxocarbon anions, which consist only of carbon and oxygen. Squaric acid is a reagent for chemical synthesis, used for instance to make photosensitive squaraine dyes and inhibitors of protein tyrosine phosphatases. Chemical properties Squaric acid is a white crystalline powder. The onset of thermal decomposition depends on the different thermodynamic conditions such as heating rates. The structure of squaric acid is not a perfect square, as the carbon–carbon bond lengths are not quite equal. The high acidity with p''K''a = 1.5 for the first proton and p''K''a = 3.4 for the second is attributable to resonance stabilization of the anion. Because t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluoroisobutene
Perfluoroisobutene (PFIB) is the perfluorocarbon counterpart of the hydrocarbon isobutene and has the formula (CF3)2C=CF2. An alkene, it is a colorless gas that is notable as a highly toxic perfluoroalkene. Few simple alkenes are as toxic. Safety Perfluoroisobutene is quite toxic with an LCt = 880 mg⋅min⋅m−3 (mice). It is a Schedule 2 substance of the Chemical Weapons Convention. Perfluoroisobutene is highly reactive toward nucleophiles. It hydrolyzes readily to give the relatively innocuous (CF3)2CHCO2H, which readily decarboxylates to give hexafluoropropane. It forms addition compounds with thiols, and it is this reactivity that may be related to its toxicity. PFIB is a product of pyrolysis of polytetrafluoroethylene (PTFE), one of the substances invoked to explain polymer fume fever. External links International Chemical Safety Card 1216 See also *Phosgene Phosgene is the organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexafluoro-2-butyne
Hexafluoro-2-butyne (HFB) is a fluorocarbon with the chemical structure CF3C≡CCF3. HFB is a particularly electrophilic acetylene derivative, and hence a potent dienophile for Diels–Alder reactions. HFB is prepared by the action of sulfur tetrafluoride on acetylenedicarboxylic acid or by the reaction of potassium fluoride (KF) with hexachlorobutadiene Hexachlorobutadiene, Cl2C=C(Cl)C(Cl)=CCl2, is a colorless liquid at room temperature that has an odor similar to that of turpentine. It is a chlorinated aliphatic diene with niche applications but is most commonly used as a solvent for other chlo .... References {{Reflist Alkyne derivatives Trifluoromethyl compounds Fluorocarbons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexafluorobutadiene
Hexafluorobutadiene is an organofluorine compound with the formula (CF2=CF)2. A colorless gas, it has attracted attention as an etchant in microelectronics. It is the perfluoroanalogue of butadiene. It can be prepared by coupling of C2 compounds such as from chlorotrifluoroethylene or bromotrifluoroethylene. Routes from C4 species have also been demonstrated. For example, an early synthesis involved Zn-induced dechlorinaion of 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane. Hexafluorobutadiene dimerizes via a +2process at 150 °C to give perfluorinated divinylcyclobutanes.{{cite book , doi=10.1002/0470864028.ch21 , title=The Chemistry of Cyclobutanes , chapter=Fluorinated Cyclobutanes and Their Derivatives, first1=David M., last1=Lemal, first2=Xudong, last2=Chen , editor=Zvi Rappoport , editor2=Joel F. Liebman, year=2005, series=PATAI'S Chemistry of Functional Groups, pages=955–1029 , isbn=0470864001 See also * Hexafluoro-2-butyne, an isomer of C4F6 * Hexafluorocyclo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluorinated Compounds
A perfluorinated compound (PFC) or perfluoro compound is an organofluorine compound containing only carbon-fluorines and C−C bonds, as well as potentially heteroatoms. Perfluorinated compounds have properties that result from the presence of fluorocarbons (containing only C−F and C−C bonds) and any functional group. Common functional groups in PFCs are OH, CO2H, chlorine, O, and SO3H. Electrofluorination is the predominant method of production. Some of these compounds known as perfluoroalkanes can remain in our atmosphere for a long time. They bioaccumulate due to their chemical stability. Because of their potential contribution to climate change, they were regulated under the Kyoto Protocol. Some fluorosurfactants have proven toxic in animal testing while widespread industrial applications continue. Applications Perfluorinated compounds are used ubiquitously: For example, fluorosurfactants are widely used in the production of teflon (PTFE) and related fluorinated po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
