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Finkelstein Reaction
The Finkelstein reaction, named after the German chemist Hans Finkelstein, is a type of SN2 reaction (substitution nucleophilic bimolecular reaction) that involves the exchange of one halogen atom for another. It is an equilibrium reaction, but the reaction can be driven to completion by exploiting the differential solubility of various halide salts, or by using a large excess of the desired halide. Method The classic Finkelstein reaction entails the conversion of an alkyl chloride or an alkyl bromide to an alkyl iodide by treatment with a solution of sodium iodide in acetone. Sodium iodide is soluble in acetone while sodium chloride and sodium bromide are not; therefore, the reaction is driven toward products by mass action due to the precipitation of the poorly soluble NaCl or NaBr. An example involves the conversion of the ethyl ester of 5-bromovaleric acid to the iodide: :EtO2C(CH2)4Br + NaI → EtO2C(CH2)4I + NaBr Potassium fluoride is used for the conversio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Finkelstein
Hans Finkelstein (17 May 1885, Leipzig, Germany - December 1938) was a German chemist. He is particularly known for the Finkelstein reaction developed by and named after him. Biography Hans Finkelstein came from a liberal Jewish family and joined the Protestant Church when he was 10 years old. He studied chemistry like his father Berthold Finkelstein, one of BASF's first chemists. After studying in Leipzig and Dresden he worked on his doctoral thesis with Johannes Thiele in Strasbourg from 1906, submitting it in 1909. Finkelstein continued his scientific work as assistant to Prof. Thiele until 1912. During this time he also translated scientific books into German with his father. In 1912 Finkelstein transitioned from university to industry as head of the research department at Bayer AG, Uerdingen. He filed some patents over the years. In 1912, Finkelstein married Annemarie Bruns. Together they had three children. In November 1938 shortly after the ''Kristallnacht'' and the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Fluoride
Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide salt and occurs naturally as the rare mineral carobbiite. Solutions of KF will etch glass due to the formation of soluble fluorosilicates, although HF is more effective. Preparation Potassium fluoride is prepared by reacting potassium carbonate with hydrofluoric acid. Evaporation of the solution forms crystals of potassium bifluoride. The bifluoride on heating yields potassium fluoride: : : Platinum or heat resistant plastic containers are often used for these operations. Potassium chloride converts to KF upon treatment with hydrogen fluoride. In this way, potassium fluoride is recyclable. Crystalline properties KF crystallizes in the cubic NaCl crystal structure. The lattice parameter at room temperature is 0.266 nm. Applications in organic chemistry In organic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloromethane
Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is an organic compound with the chemical formula . One of the haloalkanes, it is a colorless, sweet-smelling, flammable gas. Methyl chloride is a crucial reagent in industrial chemistry, although it is rarely present in consumer products, and was formerly utilized as a refrigerant. Most chloromethane is biogenic. Occurrence Chloromethane is an abundant organohalogen, anthropogenic or natural, in the atmosphere. Natural sources produce an estimated 4,100,000,000 kg/yr. Marine Laboratory cultures of marine phytoplankton (''Phaeodactylum tricornutum'', ''Phaeocystis'' sp., ''Thalassiosira weissflogii'', ''Chaetoceros calcitrans'', ''Isochrysis'' sp., ''Porphyridium'' sp., ''Synechococcus'' sp., ''Tetraselmis'' sp., ''Prorocentrum'' sp., and ''Emiliana huxleyi'') produce CH3Cl, but in relatively insignificant amounts. An extensive study of 30 species of polar macroalgae revealed the release of significant ... [...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] |
Aryl
In organic chemistry, an aryl is any functional group or substituent derived from an aromatic ring, usually an aromatic hydrocarbon, such as phenyl and naphthyl. "Aryl" is used for the sake of abbreviation or generalization, and "Ar" is used as a placeholder for the aryl group in chemical structure diagrams, analogous to “R” used for any organic substituent. “Ar” is not to be confused with the elemental symbol for argon. A simple aryl group is phenyl (), a group derived from benzene. Examples of other aryl groups consist of: * The tolyl group () which is derived from toluene (methylbenzene) * The xylyl group (), which is derived from xylene (dimethylbenzene) * The naphthyl group (), which is derived from naphthalene Arylation is the process in which an aryl group is attached to a substituent. It is typically achieved by cross-coupling reactions. Nomenclature The simplest aryl group is phenyl, which is made up of a benzene ring with one of its hydrogen atom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vinyl Group
In organic chemistry, a vinyl group (abbr. Vi; IUPAC name: ethenyl group) is a functional group with the formula . It is the ethylene (IUPAC name: ethene) molecule () with one fewer hydrogen atom. The name is also used for any compound containing that group, namely where R is any other group of atoms. An industrially important example is vinyl chloride, precursor to PVC, a plastic commonly known as ''vinyl''. Vinyl is one of the alkenyl functional groups. On a carbon skeleton, sp2-hybridized carbons or positions are often called vinylic. Allyls, acrylates and styrenics contain vinyl groups. (A styrenic crosslinker with two vinyl groups is called '' divinyl benzene''.) Vinyl polymers Vinyl groups can polymerize with the aid of a radical initiator or a catalyst, forming vinyl polymers. Vinyl polymers contain no vinyl groups. Instead they are saturated. The following table gives some examples of vinyl polymers. Synthesis and reactivity Vinyl derivatives are alke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzyl
In organic chemistry, benzyl is the substituent or molecular fragment possessing the structure . Benzyl features a benzene ring () attached to a methylene group (). Nomenclature In IUPAC nomenclature, the prefix benzyl refers to a substituent, for example benzyl chloride or benzyl benzoate. Benzyl is not to be confused with phenyl with the formula . The term benzylic is used to describe the position of the first carbon bonded to a benzene or other aromatic ring. For example, is referred to as a "benzylic" carbocation. The benzyl free radical has the formula . The benzyl cation or phenylcarbenium ion is the carbocation with formula ; the benzyl anion or phenylmethanide ion is the carbanion with the formula . None of these species can be formed in significant amounts in the solution phase under normal conditions, but they are useful referents for discussion of reaction mechanisms and may exist as reactive intermediates. Abbreviations Benzyl is most commonly abbreviated Bn. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allyl
In organic chemistry, an allyl group is a substituent with the structural formula . It consists of a methylene bridge () attached to a vinyl group (). The name is derived from the scientific name for garlic, . In 1844, Theodor Wertheim isolated an allyl derivative from garlic oil and named it "". The term allyl applies to many compounds related to , some of which are of practical or of everyday importance, for example, allyl chloride. Allylation is any chemical reaction that adds an allyl group to a Substrate (chemistry), substrate. Nomenclature A site adjacent to the unsaturated carbon atom is called the allylic position or allylic site. A group attached at this site is sometimes described as allylic. Thus, "has an allylic hydroxyl group". Allylic Carbon–hydrogen bond, C−H bonds are about 15% weaker than the C−H bonds in ordinary Orbital hybridisation, sp3 carbon centers and are thus more reactive. Benzylic and allylic are related in terms of structure, bond strength ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neopentyl
Pentyl is a five-carbon alkyl group or substituent with chemical formula . It is the substituent form of the alkane pentane. In older literature, the common non-systematic name amyl was often used for the pentyl group. Conversely, the name pentyl was used for several five-carbon branched alkyl groups, distinguished by various prefixes. The nomenclature has now reversed, with "amyl" being more often used to refer to the terminally branched group also called isopentyl, as in amobarbital. A cyclopentyl group is a ring with the formula . The name is also used for the pentyl radical, a pentyl group as an isolated molecule. This free radical is only observed in extreme conditions. Its formula is often written "•" or "• " to indicate that it has one unsatisfied valence bond. Radicals like pentyl are reactive, they react with neighboring atoms or molecules (like oxygen, water, etc.) Older "pentyl" groups The following names are still used sometimes: Pentyl radical The f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethyl Sulfoxide
Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula . This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water. It has a relatively high boiling point. DMSO is metabolised to compounds that leave a garlic-like taste in the mouth after DMSO is absorbed by skin. In terms of chemical structure, the molecule has idealized Cs symmetry. It has a trigonal pyramidal molecular geometry consistent with other three-coordinate S(IV) compounds, with a nonbonded electron pair on the approximately tetrahedral sulfur atom. Synthesis and production Dimethyl sulfoxide was first synthesized in 1866 by the Russian scientist Alexander Zaytsev, who reported his findings in 1867. Its modern use as an industrial solvent began through popularization by Thor Smedslund at the Stepan Chemical Company. Dimeth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethylene Glycol
Ethylene glycol ( IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula . It is mainly used for two purposes: as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odorless, colorless, flammable, viscous liquid. It has a sweet taste but is toxic in high concentrations. This molecule has been observed in outer space. Production Industrial routes Ethylene glycol is produced from ethylene (ethene), via the intermediate ethylene oxide. Ethylene oxide reacts with water to produce ethylene glycol according to the chemical equation : This reaction can be catalyzed by either acids or bases or can occur at neutral pH under elevated temperatures. The highest yields of ethylene glycol occur at acidic or neutral pH with a large excess of water. Under these conditions, ethylene glycol yields of 90% can be achieved. The major byproducts are the oligomers diethylene glycol, triethylene glycol, and tetra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
