|
TEMED
Tetramethylethylenediamine (TMEDA or TEMED) is a chemical compound with the formula (CH3)2NCH2CH2N(CH3)2. This species is derived from ethylenediamine by replacement of the four amine hydrogens with four methyl groups. It is a colorless liquid, although old samples often appear yellow. Its odor is similar to that of rotting fish. As a reagent in synthesis TMEDA is widely employed as a ligand for metal ions. It forms stable complexes with many metal halides, e.g. zinc chloride and copper(I) iodide, giving complexes that are soluble in organic solvents. In such complexes, TMEDA serves as a bidentate ligand. TMEDA has an affinity for lithium ions. When mixed with ''n''-butyllithium, TMEDA's nitrogen atoms coordinate to the lithium, forming a cluster of higher reactivity than the tetramer or hexamer that ''n''-butyllithium normally adopts. BuLi/TMEDA is able to metallate or even doubly metallate many substrates including benzene, furan, thiophene, ''N''-alkyl pyrroles, and ferro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triethylenetetramine
Triethylenetetramine (TETA and trien), also known as trientine (INN) when used medically, is an organic compound with the formula H2NHCH2CH2NH2sub>2. The pure freebase is a colorless oily liquid, but, like many amines, older samples assume a yellowish color due to impurities resulting from air-oxidation. It is soluble in polar solvents. The branched isomer tris(2-aminoethyl)amine and piperazine derivatives may also be present in commercial samples of TETA. The hydrochloride salts are used medically as a treatment for copper toxicity. Uses The reactivity and uses of TETA are similar to those for the related polyamines ethylenediamine and diethylenetriamine. It is primarily used as a crosslinker ("hardener") in epoxy curing. Medical uses The hydrochloride salt of TETA, referred to as ''trientine hydrochloride'', is a chelating agent that is used to bind and remove copper in the body to treat Wilson's disease, particularly in those who are intolerant to penicillamine. Some r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallate
Metallate or metalate is the name given to any complex anion containing a metal ligated to several atoms or small groups. Typically, the metal will be one of the transition elements and the ligand will be oxygen or another chalcogenide or a cyanide group (though others are known). The chalcogenide metallates are known as oxometallates, thiometallates, selenometallates and tellurometallates; the cyanide metallates are known as cyanometallates. Oxometallates include permanganate (), chromate () and vanadate ( or ). Thiometallates include tetrathiovanadate (), tetrathiomolybdate (), tetrathiotungstate () and similar ions. Cyanometallates include ferricyanide and ferrocyanide. Metallate is also used as a verb by bioinorganic chemistry Bioinorganic chemistry is a field that examines the role of metals in biology. Bioinorganic chemistry includes the study of both natural phenomena such as the behavior of metalloproteins as well as artificially introduced metals, including thos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethylamino Compounds
Dimethylamine is an organic compound with the formula (CH3)2NH. This secondary amine is a colorless, flammable gas with an ammonia-like odor. Dimethylamine is commonly encountered commercially as a solution in water at concentrations up to around 40%. An estimated 270,000 tons were produced in 2005. Structure and synthesis The molecule consists of a nitrogen atom with two methyl substituents and one proton. Dimethylamine is a weak base and the pKa of the ammonium CH3--CH3 is 10.73, a value above methylamine (10.64) and trimethylamine (9.79). Dimethylamine reacts with acids to form salts, such as dimethylamine hydrochloride, an odorless white solid with a melting point of 171.5 °C. Dimethylamine is produced by catalytic reaction of methanol and ammonia at elevated temperatures and high pressure: :2 CH3OH + NH3 → (CH3)2NH + 2 H2O Natural occurrence Dimethylamine is found quite widely distributed in animals and plants, and is present in many foods at the level of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doyle Catalyst
Doyle is a surname of Irish origin. The name is a back-formation from O'Doyle, which is an Anglicisation of the Irish (), meaning "descendant of ''Dubhghall''". There is another possible etymology: the Anglo-Norman surname ''D'Oyley'' with agglutination of the French article ''de'' (cf. Disney). It means 'from Ouilly', name of a knight who originated from one of the places named Ouilly in Normandy, such as Ouilly-le-Tesson (Calvados, ''Oylley'' 1050), Ouilly-le-Vicomte (Calvados, ''de Oilleio'' 1279), etc. The relationship with the family D'Oyly is unknown. The personal name ''Dubhghall'' contains the elements ''dubh'' "black" + ''gall'' "stranger". Similar Scottish and Irish surnames, derived from the same personal name are: ''MacDougall'' / '' McDougall'' and '' MacDowell'' / '' McDowell''. During the Viking Age the term '' Dubhghoill'' was used to describe the Vikings—usually Danes—and the term ''Fionnghoill'' ("fair foreigners") was used to describe Norwegians. There i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetramethylethylenediamine(dimethyl)nickel(II)
Tetramethylethylenediamine(dimethyl)nickel(II) is the organonickel complex with the formula (Me = CH3). This yellow-brown, air-sensitive compound is popular precursor to diverse organonickel complexes. It is prepared from the tmeda adduct of nickel(II) acetylacetonate by reaction with methyl lithium.{{cite journal , doi=10.1016/0022-328X(88)89050-8, title=Tmeda-Nickel-Komplexe , year=1988 , last1=Kaschube , first1=Wilfried , last2=Pörschke , first2=Klaus R. , last3=Wilke , first3=Günther , journal=Journal of Organometallic Chemistry , volume=355 , issue=1–3 , pages=525–532 The tmeda ligand is easily displaced by bases such as bipyridine and diphosphines. Treatment of the complex with electrophilic alkenes results in elimination of ethylene, giving alkene complexes. References Organonickel compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sec-Butyllithium
''sec''-Butyllithium is an organometallic compound with the formula CH3CHLiCH2CH3, abbreviated ''sec''-BuLi or ''s''-BuLi. This chiral organolithium reagent is used as a source of ''sec''-butyl carbanion in organic synthesis.. Synthesis ''sec''-BuLi can be prepared by the reaction of ''sec''-butyl halides with lithium metal: Properties Physical properties ''sec''-Butyllithium is a colorless viscous liquid. Using mass spectrometry, it was determined that the pure compound has a tetrameric structure. It also exists as tetramers when dissolved in organic solvents such as benzene, cyclohexane or cyclopentane. The cyclopentane solution has been detected with 6Li-NMR spectroscopy to have a hexameric structure at temperatures below −41 °C. In electron-donating solvents such as tetrahydrofuran, there exists an equilibrium between monomeric and dimeric forms. Chemical properties The carbon-lithium bond is highly polar, rendering the carbon basic, as in other organolithium reag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Ammonium Salt
In chemistry, quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure , R being an alkyl group or an aryl group. Unlike the ammonium ion () and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged, independent of the pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds (called quaternary amines in oilfield parlance) are salts of quaternary ammonium cations. Polyquats are a variety of engineered polymer forms which provide multiple quat molecules within a larger molecule. Quats are used in consumer applications including as antimicrobials (such as detergents and disinfectants), fabric softeners, and hair conditioners. As an antimicrobial, they are able to inactivate enveloped viruses (such as SARS-CoV-2). Quats tend to be gentler on surfaces than bleach-based disinfectants, and are generally fabric-safe. Synthesis Quaternary ammonium comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of The American Chemical Society
The ''Journal of the American Chemical Society'' is a weekly peer-reviewed scientific journal that was established in 1879 by the American Chemical Society. The journal has absorbed two other publications in its history, the ''Journal of Analytical and Applied Chemistry'' (July 1893) and the ''American Chemical Journal'' (January 1914). It covers all fields of chemistry. Since 2021, the editor-in-chief is Erick M. Carreira (ETH Zurich). In 2014, the journal moved to a hybrid open access publishing model. Abstracting and indexing The journal is abstracted and indexed in Chemical Abstracts Service, Scopus, EBSCO databases, ProQuest databases, Index Medicus/MEDLINE/PubMed, and the Science Citation Index Expanded. According to the ''Journal Citation Reports'', the journal has a 2021 impact factor of 16.383. Editors-in-chief The following people are or have been editor-in-chief: * 1879–1880 – Hermann Endemann * 1880–1881 – Gideon E. Moore * 1881–1882 – Hermann Endemann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrocene
Ferrocene is an organometallic compound with the formula . The molecule is a complex consisting of two cyclopentadienyl rings bound to a central iron atom. It is an orange solid with a camphor-like odor, that sublimes above room temperature, and is soluble in most organic solvents. It is remarkable for its stability: it is unaffected by air, water, strong bases, and can be heated to 400 °C without decomposition. In oxidizing conditions it can reversibly react with strong acids to form the ferrocenium cation . The rapid growth of organometallic chemistry is often attributed to the excitement arising from the discovery of ferrocene and its many analogues, such as metallocenes. History Discovery Ferrocene was discovered by accident thrice. The first known synthesis may have been made in the late 1940s by unknown researchers at Union Carbide, who tried to pass hot cyclopentadiene vapor through an iron pipe. The vapor reacted with the pipe wall, creating a "yellow sludg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrole
Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4 H4 NH. It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., ''N''-methylpyrrole, C4H4NCH3. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme. Pyrroles are components of more complex macrocycles, including the porphyrinogens and products derived therefrom, including porphyrins of heme, the chlorins, bacteriochlorins, and chlorophylls. Properties Pyrrole is a colorless volatile liquid that darkens readily upon exposure to air, and is usually purified by distillation immediately before use. Pyrrole has a nutty odor. Pyrrole is a 5-membered aromatic heterocycle, like furan and thiophene. Unlike furan and thiophene, it has a dipole in which the positive end lies on the side of the heteroatom, with a dipole moment of 1.58 D. In CDCl3, it has ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiophene
Thiophene is a heterocyclic compound with the formula C4H4S. Consisting of a planar five-membered ring, it is aromatic as indicated by its extensive substitution reactions. It is a colorless liquid with a benzene-like odor. In most of its reactions, it resembles benzene. Compounds analogous to thiophene include furan (C4H4O), selenophene (C4H4Se) and pyrrole (C4H4NH), which each vary by the heteroatom in the ring. Isolation and occurrence Thiophene was discovered as a contaminant in benzene. It was observed that isatin (an indole) forms a blue dye if it is mixed with sulfuric acid and crude benzene. The formation of the blue indophenin had long been believed to be a reaction of benzene itself. Viktor Meyer was able to isolate thiophene as the actual substance responsible for this reaction. Thiophene and especially its derivatives occur in petroleum, sometimes in concentrations up to 1–3%. The thiophenic content of oil and coal is removed via the hydrodesulfurization (HDS) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
