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Wohl–Ziegler Bromination
The Wohl–Ziegler reaction is a chemical reaction that involves the allylic or benzylic bromination of hydrocarbons using an ''N''-bromosuccinimide and a radical initiator. : Best yields are achieved with ''N''-bromosuccinimide in carbon tetrachloride solvent. Several reviews have been published. In a typical setup, a stoichiometric amount of ''N''-bromosuccinimide solution and a small quantity of initiator are added to a solution of the substrate in CCl4, and the reaction mixture is stirred and heated to the boiling point. Initiation of the reaction is indicated by more vigorous boiling; sometimes the heat source may need to be removed. Once all ''N''-bromosuccinimide (which is denser than the solvent) has been converted to succinimide (which floats on top) the reaction has finished. Due to the high toxicity and ozone-depleting nature of carbon tetrachloride, trifluorotoluene Trifluorotoluene is an organic compound with the formula of C6H5CF3. This colorless fluorocarbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Wohl
Alfred Wohl (3 October 1863 – 25 December 1939) was a German chemist. Several chemical reactions are named after him, including the Wohl degradation, Wohl–Aue reaction and the Wohl–Ziegler reaction. Life Wohl studied chemistry at the University of Heidelberg from 1882 until 1886. He received his Ph.D 1886 for work on Hexamethylenetetramine with August Wilhelm von Hofmann. He became an assistant of Hermann Emil Fischer at the University of Berlin from 1886 until 1891, where he also received his habilitation. He became professor at the University of Berlin in 1901, but he left for the Technische Hochschule Danzig in 1904. He retired because of antisemitic pressure in 1933, but worked in his lab until 1937. He emigrated to Sweden in 1938, where he died in 1939. His son Kurt Wohl (1896–1962) – who also became a renowned chemical scientist – emigrated to Great Britain in 1939 and some years later to the United States. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Tetrachloride
Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC), is a chemical compound with the chemical formula CCl4. It is a non-flammable, dense, colourless liquid with a "sweet" chloroform-like odour that can be detected at low levels. It was formerly widely used in fire extinguishers, as a precursor to refrigerants, an anthelmintic and a cleaning agent, but has since been phased out because of environmental and safety concerns. Exposure to high concentrations of carbon tetrachloride can affect the central nervous system and degenerate the liver and kidneys. Prolonged exposure can be fatal. Properties In the carbon tetrachloride molecule, four chlorine atoms are positioned symmetrically as corners in a tetrahedron, tetrahedral configuration joined to a central carbon atom by single covalent bonds. Because of this symmetric geometry, CCl4 is non-polar. methane, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halogenation Reactions
In chemistry, halogenation is a chemical reaction which introduces one or more halogens into a chemical compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drugs. This kind of conversion is in fact so common that a comprehensive overview is challenging. This article mainly deals with halogenation using elemental halogens (). Halides are also commonly introduced using salts of the halides and halogen acids. Many specialized reagents exist for introducing halogens into diverse substrates, e.g. thionyl chloride. Organic chemistry Several pathways exist for the halogenation of organic compounds, including free radical halogenation, ketone halogenation, electrophilic halogenation, and halogen addition reaction. The nature of the substrate determines the pathway. The facility of halogenation is influenced by the halogen. Fluorine and chlorine are more electrophilic and are more aggressive halogenating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free-radical Halogenation
In organic chemistry, free-radical halogenation is a type of halogenation. This chemical reaction is typical of alkanes and alkyl-substituted aromatics under application of UV light. The reaction is used for the industrial synthesis of chloroform (CHCl3), dichloromethane (CH2Cl2), and hexachlorobutadiene. It proceeds by a free-radical chain mechanism. General mechanism The chain mechanism is as follows, using the chlorination of methane as an example: ; Initiation: Ultraviolet radiation splits ( homolyzes) a chlorine molecule to two chlorine atom radicals. ; Chain propagation (two steps): A radical abstracts a hydrogen atom from methane, leaving a primary methyl radical. The methyl radical then abstracts Cl• from Cl2 to give the desired product and another chlorine radical. The radical will then participate in another propagation reaction: the radical chain. Other products such as CH2Cl2 may also form. ; Chain termination: Two free radicals (chlorine and chlorine, chlor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Addition Vs
Addition (usually signified by the plus symbol, +) is one of the four basic operations of arithmetic, the other three being subtraction, multiplication, and division. The addition of two whole numbers results in the total or '' sum'' of those values combined. For example, the adjacent image shows two columns of apples, one with three apples and the other with two apples, totaling to five apples. This observation is expressed as , which is read as "three plus two equals five". Besides counting items, addition can also be defined and executed without referring to concrete objects, using abstractions called numbers instead, such as integers, real numbers, and complex numbers. Addition belongs to arithmetic, a branch of mathematics. In algebra, another area of mathematics, addition can also be performed on abstract objects such as vectors, matrices, subspaces, and subgroups. Addition has several important properties. It is commutative, meaning that the order of the numbers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goldfinger And Bloomfield Mechanisms
Goldfinger may refer to: ''James Bond'' * ''Goldfinger'' (novel), a 1959 James Bond novel written by Ian Fleming ** ''Goldfinger'' (film), a 1964 James Bond film starring Sean Connery *** ''Goldfinger'' (soundtrack), the soundtrack to the film composed by John Barry *** "Goldfinger" (Shirley Bassey song), the title song of the film performed by Shirley Bassey ** Auric Goldfinger, the eponymous villain of the novel and film ''Goldfinger'' ** ''James Bond 007: Goldfinger'', a 1986 videogame; see James Bond in video games ** ''Goldfinger'' (adventure), a 1983 adventure scenario for the role-playing game ''James Bond 007'' Music * Goldfinger (band), an American punk rock band ** ''Goldfinger'' (album), the 1996 first album by Goldfinger * "Goldfinger" (Ash song), 1996 * "Goldfinger", a song by Die Krupps from ''Volle Kraft voraus!'' * "Goldfinger 2019", a song by Japanese musician Koda Kumi People * Goldfinger (surname) People with the nickname * Andrew Gilding (born 1970 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trifluorotoluene
Trifluorotoluene is an organic compound with the formula of C6H5CF3. This colorless fluorocarbon is used as a specialty solvent in organic synthesis and an intermediate in the production of pesticides and pharmaceuticals.Banks, R.E. Organofluorine Chemicals and their Industrial Applications, Ellis Horwood LTD, Chichester, 1979. Synthesis For small-scale laboratory preparations, trifluorotoluene is synthesized by coupling an aromatic halide and trifluoromethyl iodide in the presence of a copper catalyst: :PhX + CF3I → PhCF3 (where X = I, Br) Industrial production is done by reacting benzotrichloride with hydrogen fluoride in a pressurized reactor.Siegemund, Günter "Aromatic Compounds with Fluorinated Side-Chains" in Ullmann’s Encyclopedia of Industrial Chemistry 2005, Wiley-VCH. . :PhCCl3 + 3 HF → PhCF3 + 3 HCl Uses Trifluorotoluene has a variety of niche uses. Low toxicity alternative to dichloromethane According to Ogawa and Curran, trifluorotoluene is similar to d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Succinimide
Succinimide is an organic compound with the formula (CH2)2(CO)2NH. This white solid is used in a variety of organic syntheses, as well as in some industrial silver plating processes. The compound is classified as a cyclic imide. It may be prepared by thermal decomposition of ammonium succinate. Succinimides Succinimides refers to compounds that contain the succinimide group. These compounds have some notable uses. Several succinimides are used as anticonvulsant drugs, including ethosuximide, phensuximide, and methsuximide. Succinimides are also used to form covalent bonds between proteins or peptides and plastics, which is useful in a variety of assay techniques. See also * Succinic anhydride * N-Hydroxysuccinimide, ''N''-Hydroxysuccinimide * N-Bromosuccinimide, ''N''-Bromosuccinimide References {{Authority control Succinimides, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chem , a place in Finland
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Chem may refer to: *Chemistry *Chemical * ''Chem'' (journal), a scientific journal published by Cell Press *Post apocalyptic slang for "drugs", medicinal or otherwise in the Fallout video game series. In Ancient Egyptian usage: * ''Khem'' (also spelt ''Chem''), the Egyptian word for "black" *Min (god), in the past erroneously named ''Khem'' CHEM may refer to : *A metabolic panel: for instance, CHEM-7, which is the basic metabolic panel * CHEM-DT, a Canadian television channel See also * Chemo (other) * Kem (other) *Kemi Kemi (; ; ; ) is a cities of Finland, town and municipalities of Finland, municipality of Finland. It is located approximately from the city of Tornio and the Finland–Sweden border, Swedish border. The distance to Oulu is to the south and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Ziegler
Karl Waldemar Ziegler (; 26 November 1898 – 12 August 1973) was a German chemist who won the Nobel Prize in Chemistry in 1963, with Giulio Natta, for work on polymers. The Nobel Committee recognized his "excellent work on organometallic compounds hich..led to new polymerization reactions and ... paved the way for new and highly useful industrial processes". He is also known for his work involving free-radicals, many-membered rings, and organometallic compounds, as well as the development of Ziegler–Natta catalyst. One of many awards Ziegler received was the Werner von Siemens Ring in 1960 jointly with Otto Bayer and Walter Reppe, for expanding the scientific knowledge of and the technical development of new synthetic materials. Biography Early life and education Karl Ziegler was born on 26 November 1898 in Helsa near Kassel, Germany and was the second son of Karl Ziegler, a Lutheran minister, and Luise Rall Ziegler. He attended Kassel-Bettenhausen in elementary scho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
