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Triazol-5-ylidene
The triazol-5-ylidenes are a group of Persistent carbene, persistent carbenes which includes the 1,2,4-triazol-5-ylidene system and the 1,2,3-triazol-5-ylidene system. As opposed to the now ubiquitous NHC (N-heterocyclic carbene) systems based on imidazole rings, these carbenes are structured from triazole rings. 1,2,4-triazol-5-ylidene can be thought of as an analog member of the NHC family, with an extra nitrogen in the ring, while 1,2,3-triazol-5-ylidene is better thought of as a Mesoionic carbene, mesoionic carbene (MIC). Both isomers of this group of carbenes benefit from enhanced stability, with certain examples exhibiting greater thermal stability, and others extended shelf life. The 1,2,4-triazol-5-ylidene system is of special historic interest, as this system contains the first known instance of a characterized NHC, a compound colloquially known as Nitron, which was first isolated in 1905. This compound was first proposed as an analytical reagent for the gravimetric analysi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triazol-5-ylidene Isomers
The triazol-5-ylidenes are a group of Persistent carbene, persistent carbenes which includes the 1,2,4-triazol-5-ylidene system and the 1,2,3-triazol-5-ylidene system. As opposed to the now ubiquitous NHC (N-heterocyclic carbene) systems based on imidazole rings, these carbenes are structured from triazole rings. 1,2,4-triazol-5-ylidene can be thought of as an analog member of the NHC family, with an extra nitrogen in the ring, while 1,2,3-triazol-5-ylidene is better thought of as a Mesoionic carbene, mesoionic carbene (MIC). Both isomers of this group of carbenes benefit from enhanced stability, with certain examples exhibiting greater thermal stability, and others extended shelf life. The 1,2,4-triazol-5-ylidene system is of special historic interest, as this system contains the first known instance of a characterized NHC, a compound colloquially known as Nitron, which was first isolated in 1905. This compound was first proposed as an analytical reagent for the gravimetric analysi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistent Carbene
A persistent carbene (also known as stable carbene) is a type of carbene demonstrating particular stability. The best-known examples and by far largest subgroup are the ''N''-heterocyclic carbenes (NHC) (sometimes called Arduengo carbenes), for example diaminocarbenes with the general formula (R2N)2C:, where the four R moieties are typically alkyl and aryl groups. The groups can be linked to give heterocyclic carbenes, such as those derived from imidazole, imidazoline, thiazole or triazole. Traditionally carbenes are viewed as so reactive that were only studied indirectly, such as by trapping reactions. This situation has changed dramatically with the emergence of persistent carbenes. Although they are fairly reactive substances, undergoing dimerization, many can be isolated as pure substances. Persistent carbenes tend to exist in the singlet. Their stability is only partly due to steric hindrance by bulky groups. Some singlet carbenes are thermodynamically stable and can be iso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guy Bertrand (chemist)
Guy Bertrand, born on July 17, 1952 at Limoges is a chemistry professor at the University of California, San Diego. Bertrand obtained his B.Sc. from the University of Montpellier in 1975 and his Ph.D. from the Paul Sabatier University, Toulouse, in 1979. He was a postdoctoral researcher at Sanofi Research, France, in 1981. Guy Bertrand's faculty homepageat UC San Diego. Accessed on 2013-1-22. The research interests of Bertrand and his co-workers lie mainly in the chemistry of with main group elements from group 13 to 16, at the border between organic, organometallic and inorganic chemistry; especially their use in stabilizing carbenes, nitrenes, phosphinidenes, radicals and biradicals, 1,3-dipoles, anti-aromatic heterocycles, and more. He has directed the synthesis of some original persistent carbenes, including bis(diisopropylamino)cyclopropenylidene, the first example of a carbene with all-carbon environment that is stable at room-temperature.V. Lavallo, Y. Canac, B. Donna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organocatalysis
In organic chemistry, organocatalysis is a form of catalysis in which the rate of a chemical reaction is increased by an organic catalyst. This "organocatalyst" consists of carbon, hydrogen, sulfur and other nonmetal elements found in organic compounds.Special Issue: Because of their similarity in composition and description, they are often mistaken as a misnomer for enzymes due to their comparable effects on reaction rates and forms of catalysis involved. Organocatalysts which display secondary amine functionality can be described as performing either enamine catalysis (by forming catalytic quantities of an active enamine nucleophile) or iminium catalysis (by forming catalytic quantities of an activated iminium electrophile). This mechanism is typical for covalent organocatalysis. Covalent binding of substrate normally requires high catalyst loading (for proline-catalysis typically 20–30 mol%). Noncovalent interactions such as hydrogen-bonding facilitates low catalyst l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Click Chemistry
In chemical synthesis, click chemistry is a class of biocompatible small molecule reactions commonly used in bioconjugation, allowing the joining of substrates of choice with specific biomolecules. Click chemistry is not a single specific reaction, but describes a way of generating products that follow examples in nature, which also generates substances by joining small modular units. In many applications, click reactions join a biomolecule and a reporter molecule. Click chemistry is not limited to biological conditions: the concept of a "click" reaction has been used in chemoproteomic, pharmacological, and various biomimetic applications. However, they have been made notably useful in the detection, localization and qualification of biomolecules. Click reactions occur in one pot, are not disturbed by water, generate minimal and inoffensive byproducts, and are "spring-loaded"—characterized by a high thermodynamic driving force that drives it quickly and irreversibly to high yi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Methoxide
Sodium methoxide is the simplest sodium alkoxide. With the formula , it is a white solid, which is formed by the deprotonation of methanol. Itis a widely used reagent in industry and the laboratory. It is also a dangerously caustic base. Preparation and structure Sodium methoxide is prepared by treating methanol with sodium: : The reaction is so exothermic that ignition is possible. The resulting solution, which is colorless, is often used as a source of sodium methoxide, but the pure material can be isolated by evaporation followed by heating to remove residual methanol. As a solid, sodium methoxide is polymeric, with sheet-like arrays of centers, each bonded to four oxygen centers. The structure, and hence the basicity, of sodium methoxide in solution depends on the solvent. It is a significantly stronger base in DMSO where it is more fully ionized and free of hydrogen bonding. Applications Organic synthesis Sodium methoxide is a routinely used base in organic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzoyl Chloride
Benzoyl chloride, also known as benzenecarbonyl chloride, is an organochlorine compound with the formula . It is a colourless, fuming liquid with an irritating odour, and consists of a benzene ring () with an acyl chloride () substituent. It is mainly useful for the production of peroxides but is generally useful in other areas such as in the preparation of dyes, perfumes, pharmaceuticals, and resins. Preparation Benzoyl chloride is produced from benzotrichloride using either water or benzoic acid: :C6H5CCl3 + H2O -> C6H5COCl + 2 HCl :C6H5CCl3 + C6H5CO2H -> 2 C6H5COCl + HCl As with other acyl chlorides, it can be generated from the parent acid and standard chlorinating agents such as phosphorus pentachloride, thionyl chloride, and oxalyl chloride. It was first prepared by treatment of benzaldehyde with chlorine. An early method for production of benzoyl chloride involved chlorination of benzyl alcohol. Reactions It reacts with water to produce hydrochloric acid and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enders Carbene Synthesis
Enders or Ender's may refer to: Literature and film * ''Ender's Game'' (series), a series of science fiction books by Orson Scott Card, also known as the Ender saga ** ''Ender's Game'', a 1985 military science fiction novel ** ''Ender's Shadow'', a 1999 parallel science fiction novel ** '' A War of Gifts: An Ender Story'', a 2007 science fiction novel ** '' Ender in Exile'', a 2008 science fiction novel * ''Ender's Game'' (film), a 2013 American science fiction action film based on the novel Places * Enders, Nebraska, US * Enders, Pennsylvania, US * Enders Island, Connecticut, US People * Arthur Enders (born 1982), also known as "Ace" Enders, former lead singer and guitarist of the defunct band The Early November * Courtney Enders (born 1986), drag racer * Dieter Enders (born 1946), organic chemist who has made contributions to the field of asymmetric synthesis * Erica Enders (born 1983), champion drag racer * John Franklin Enders (1897–1985), Nobel laureate who helped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthony Joseph Arduengo III
Anthony Joseph Arduengo III is Professor of the Practice at the Georgia Institute of Technology, Saxon Professor Emeritus of Chemistry at the University of Alabama, adjunct professor at the Institute for Inorganic Chemistry of Braunschweig University of Technology in Germany, and co-founder of the ''StanCE'' coalition for sustainable chemistry based on woody biomassXylochemistry. He is notable for his work on chemical compounds with unusual valency, especially in the field of stable carbene research. Early life Anthony "Bo" Arduengo was born in 1952 in Tampa, Florida. He grew up in the Atlanta, Georgia area. His father was a pressman and mechanic with the Atlanta Journal-Constitution and instilled his son with an interest and skill for all things mechanical and scientific. By the age of 16, he and his father had built his first car from miscellaneous parts. The car was registered as street-legal and road-worthy. With some re-engineering, the car was later fitted to run on al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans-Werner Wanzlick
Hans-Werner Wanzlick (1917-1988) was a German chemist. A Professor of chemistry at the Berlin Technical University he is notable for work on persistent carbenes and for proposing the Wanzlick equilibrium between saturated imidazolin-2-ylidenes and their dimer Dimer may refer to: * Dimer (chemistry), a chemical structure formed from two similar sub-units ** Protein dimer, a protein quaternary structure ** d-dimer * Dimer model, an item in statistical mechanics, based on ''domino tiling'' * Julius Dimer ...s — which he called "''das doppelte Lottchen''", after a 1949 novel by Erich Kästner about a pair of mischievous twins. Anthony J. Arduengo, III (1999) ''Looking for Stable Carbenes: The Difficulty in Starting Anew''. Accounts of Chemical Research, volume 32, number 11, pages 913–921. References * Hans-Werner Wanzlick (1958), letter to Linus Pauling (in German). Linus Pauling's Correspondence, item #444.6. Technical University of Berlin faculty 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitron Reactions with the formula
{{disambiguation ...
Nitron can refer to: * The original Greek form of the word nitre, whence nitrogen * A finish applied to certain firearms; see ferritic nitrocarburizing * The ring name of Canadian actor and former professional wrestler Daryl Karolat, who is better known by the stage name Tyler Mane * A fictional element which was being extracted from the Earth's atmosphere in '' Flash Gordon's Trip to Mars'' (1938) * The humanoid warrior from the series ''Tattooed Teenage Alien Fighters from Beverly Hills'' * A chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
