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Pentafluorobenzene
Pentafluorobenzene is an organofluoride compound with the molecular formula . The compound consists of a benzene ring substituted with five fluorine atoms. The substance is a colorless liquid with a boiling point similar to that of benzene.''CRC Handbook of Chemistry and Physics'', 90. Edition, CRC Press, Boca Raton, Florida, 2009, , Section 3, ''Physical Constants of Organic Compounds'', p. 3-414. It is prepared by defluorination of highly fluorinated cyclohexanes over hot nickel or iron. Another method involved dehydrofluorination of polyfluorinated cyclohexane using hot aqueous solution of KOH. See also *Hexafluorobenzene *Pentachlorobenzene *Fluorobenzene Fluorobenzene is the chemical compound with the formula C6H5F, often abbreviated PhF. A colorless liquid, it is a precursor to many fluorophenyl compounds. Preparation PhF was first reported in 1886 by O. Wallach at the University of Bonn, who ... References {{Reflist Fluoroarenes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexafluorobenzene
Hexafluorobenzene, HFB, , or perfluorobenzene is an organic, aromatic compound. In this derivative of benzene all hydrogen atoms have been replaced by fluorine atoms. The technical uses of the compound are limited, although it is recommended as a solvent in a number of photochemical reactions. In the laboratory hexafluorobenzene is used as standard in fluorine-19 NMR spectroscopy, solvent and standard in carbon-13 NMR, solvent in proton NMR, solvent when studying some parts in the infrared and solvent in ultraviolet–visible spectroscopy, as hexafluorobenzene itself hardly shows any absorbance in the UV region. Geometry of the aromatic ring Hexafluorobenzene stands somewhat aside in the perhalogenbenzenes. When counting for bond angles and distances it is possible to calculate the distance between two ortho fluorine atoms. Also the non bonding radius of the halogens is known. The following table presents the results: The conclusion of the table is hexafluorobenzene is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentachlorobenzene
Pentachlorobenzene (PeCB) is a chemical compound with the molecular formula C6HCl5 which is a chlorinated aromatic hydrocarbon. It consists of a benzene ring substituted with five chlorine atoms. PeCB was once used industrially for a variety of uses, but because of environmental concerns there are currently no large scale uses of PeCB.Pentachlorobenzene – Sources, environmental fate and risk characterization , Robert E. Bailey, EuroChlor, July 2007 Pentachlorobenzene is a known (POP) and banned globally by the |
Organofluoride
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 fluor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigma Aldrich
Sigma-Aldrich (formally MilliporeSigma) is an American chemical, life science, and biotechnology company that is owned by the German chemical conglomerate Merck Group. Sigma-Aldrich was created in 1975 by the merger of Sigma Chemical Company and Aldrich Chemical Company. It grew through various acquisitions until it had over 9,600 employees and was listed on the Fortune 1000. The company is headquartered in St. Louis and has operations in approximately 40 countries. In 2015, the German chemical conglomerate Merck Group acquired Sigma-Aldrich for $17 billion. The company is currently a part of Merck's life science business and in combination with Merck's earlier acquired Millipore, operates as MilliporeSigma. History Sigma Chemical Company of St. Louis and Aldrich Chemical Company of Milwaukee were both American specialty chemical companies when they merged in August 1975. The company grew throughout the 1980s and 1990s, with significant expansion in facilities, acquisitions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzene Ring
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. It is used primarily as a precursor to the manufacture of chemicals with more complex structure, such as ethylbenzene and cumene, of which billions of kilograms are produced annually. Although benzene is a major industrial chemical, it finds limited use in consumer items because of its toxicity. History Discovery The word "''benzene''" derives from "''gum benzoin''" (benzoin resi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRC Handbook Of Chemistry And Physics
The ''CRC Handbook of Chemistry and Physics'' is a comprehensive one-volume reference resource for science research. First published in 1914, it is currently () in its 103rd edition, published in 2022. It is sometimes nicknamed the "Rubber Bible" or the "Rubber Book", as CRC originally stood for "Chemical Rubber Company". As late as the 1962–1963 edition (3604 pages) the ''Handbook'' contained myriad information for every branch of science and engineering. Sections in that edition include: Mathematics, Properties and Physical Constants, Chemical Tables, Properties of Matter, Heat, Hygrometric and Barometric Tables, Sound, Quantities and Units, and Miscellaneous. Earlier editions included sections such as "Antidotes of Poisons", "Rules for Naming Organic Compounds", "Surface Tension of Fused Salts", "Percent Composition of Anti-Freeze Solutions", "Spark-gap Voltages", "Greek Alphabet", "Musical Scales", "Pigments and Dyes", "Comparison of Tons and Pounds", "Twist Drill and St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorobenzene
Fluorobenzene is the chemical compound with the formula C6H5F, often abbreviated PhF. A colorless liquid, it is a precursor to many fluorophenyl compounds. Preparation PhF was first reported in 1886 by O. Wallach at the University of Bonn, who prepared the compound in two steps. Phenyldiazonium chloride was first converted to a triazene using piperidine: : hN2l + 2 (CH2)5NH → PhN=N-N(CH2)5 + CH2)5NH2l The triazine was then cleaved with hydrofluoric acid: :PhN=N-N(CH2)5 + 2 HF → PhF + N2 + CH2)5NH2 Historical note: in Wallach's era, the element fluorine was symbolized with "Fl". Thus, his procedure is subtitled "Fluorbenzol, C6H5Fl". On the laboratory scale, PhF is prepared by the thermal decomposition of the benzenediazonium tetrafluoroborate: :PhN2BF4 → PhF + BF3 + N2 According to the procedure, solid hN2F4 is heated with a flame to initiate an exothermic reaction, which also affords boron trifluoride and nitrogen gas. Product PhF and BF3 are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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