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Lithium Tert-butoxide
Lithium ''tert''-butoxide is the metalorganic compound with the formula LiOC(CH3)3. A white solid, it is used as a strong base in organic synthesis. The compound is often depicted as a salt, and it often behaves as such, but it is not ionized in solution. Both octameric and hexameric forms have been characterized by X-ray crystallography. Preparation Lithium ''tert''-butoxide is commercially available as a solution and as a solid, but it is often generated ''in situ'' for laboratory use because samples are so sensitive and older samples are often of poor quality. It can be obtained by treating tert-butanol with butyl lithium. Reactions As a strong base, lithium ''tert''-butoxide is easily protonated. Lithium ''tert''-butoxide is used to prepare other ''tert''-butoxide compounds such as copper(I) t-butoxide and hexa(tert-butoxy)dimolybdenum(III): :2 MoCl3(thf)3 + 6 LiOBu-t → Mo2(OBu-t)6 + 6 LiCl + 6 thf Related compounds *Sodium tert-butoxide *Potassium tert-buto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metalorganic Compound
Metal-organic compounds (jargon: metalorganics, metallo-organics) are a class of chemical compounds that contain metals and organic ligands, but lacking direct metal-carbon bonds. Metal β-diketonates, metal alkoxides, metal dialkylamides, transition metal carboxylate complexes, metal acetylacetonates, and metal phosphine complexes are representative members of this class. Some of metal-organic compounds confer solubility in organic solvents or volatility. Compounds with these properties find applications in materials science for metal organic vapor deposition (MOCVD) or sol-gel processing. Precise definitions of metal-organic compound may vary, however the term may describe: *Organometallic chemistry * Metal coordination complex A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ' ...es o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Synthesis
Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the general subject of organic synthesis, there are many different types of synthetic routes that can be completed including total synthesis, Enantioselective synthesis, stereoselective synthesis, automated synthesis, and many more. Additionally, in understanding organic synthesis it is necessary to be familiar with the methodology, techniques, and applications of the subject. Total synthesis A total synthesis refers to the complete chemical synthesis of molecules from simple, Precursor (chemistry), natural precursors. Total synthesis is accomplished either via a linear or convergent approach. In a Linear synthesis, ''linear'' synthesis—often adequate for simple structures—several steps are performed sequentially until the molecule is com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring the angles and intensities of the X-ray diffraction, a crystallography, crystallographer can produce a three-dimensional picture of the density of electrons within the crystal and the positions of the atoms, as well as their chemical bonds, crystallographic disorder, and other information. X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences between various materials, especially minerals and alloys. The method has also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Csd Code ZZZJZU01side View
CSD may refer to: Finance * Central securities depository * Confederate States Dollar * Serbian dinar, by previous ISO 4217 code Organizations Education * California School for the Deaf (other), several institutions * Canyons School District, in Utah, US * Cheltenham School District, in Pennsylvania, US * Christina School District, in Delaware, US * Cleveland School District, in Mississippi, US * Cordova School District, in Alaska, US Other organizations * Canteen Stores Department (India), a chain of stores operated by the Indian Ministry of Defence at military bases * CSD Pakistan (Canteen Stores Department), a chain of stores operated by the Pakistani Ministry of Defence * Chartered Society of Designers, a British learned society for various kinds of design work * Commission on Sustainable Development (1992–2013), a former UN agency * Communication Service for the Deaf, an American non-profit company providing ASL services * Congress of Democratic Trade Unions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper(I) T-butoxide
Copper(I) ''tert''-butoxide is an alkoxide of copper(I). It is a white sublimable solid. It is a reagent in the synthesis of other copper compounds. The compound was originally obtained by salt metathesis from lithium tert-butoxide and copper(I) chloride Copper(I) chloride, commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentrated hydrochloric acid. Impure samples appear gr .... An octameric form was obtained by alcoholysis of mesitylcopper:{{cite journal, title=Copper(I) alkoxides: preparation and structural characterisation of triphenylmethoxocopper(I) and of an octanuclear form of t-butoxocopper(I) , author1=Håkansson, M. , author2=Lopes, C. , author3=Jagner, S. , journal=Inorganica Chimica Acta, year=2000, volume=304, issue=2 , pages=178–183, doi=10.1016/S0020-1693(00)00081-5 :8 CuC6H2Me3 + 8 HOBu-t → 8 HC6H2Me3 + [CuOBu-t]8 References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexa(tert-butoxy)dimolybdenum(III)
Hexa(''tert''-butoxy)dimolybdenum(III) is a coordination complex of molybdenum(III). It is one of the homoleptic alkoxides of molybdenum. An orange, air-sensitive solid, the complex has attracted academic attention as the precursor to many organomolybdenum derivatives. It an example of a charge-neutral complex featuring a molybdenum to molybdenum triple bond (Mo≡Mo), arising from the coupling of a pair of d3 metal centers. It can be prepared by a salt metathesis reaction from the THF Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is ma ... complex of molybdenum trichloride and lithium tert-butoxide: :2 MoCl3(thf)3 + 6 LiOBu-t → Mo2(OBu-t)6 + 6 LiCl + 6 thf The complex and its ditungsten (W2) analogue adopt an ethane-like geometry. The metal to metal bond distance is 222&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Tert-butoxide
Sodium ''tert''-butoxide (or sodium ''t''-butoxide) is a chemical compound with the formula (CH3)3CONa (abbr. NaOtBu). It is a strong, non-nucleophilic base. It is flammable and moisture sensitive. It is sometimes written in the chemical literature as sodium ''t''-butoxide. It is similar in reactivity to the more common potassium ''tert''-butoxide. The compound can be produced by treating ''tert''-butyl alcohol with sodium hydride. Reactions One application for sodium ''tert''-butoxide is as a non-nucleophilic base. It has been widely used in the Buchwald–Hartwig amination, as in this typical example: Sodium tert-butoxide is used to prepare tert-butoxide complexes. For example hexa(tert-butoxy)ditungsten(III) is thus obtained by the salt metathesis reaction from a ditungsten heptachloride: :NaW2Cl7(THF)5 + 6 NaOBu-t → W2(OBu-t)6 + 7 NaCl + 5 THF Structure Sodium ''tert''-butoxide forms clusters in the solid state, both hexamers and nonamers. Related compou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Tert-butoxide
Potassium ''tert''-butoxide (or potassium ''t''-butoxide) is a chemical compound with the formula CH3)3COKsub>''n'' (abbr. KOtBu). This colourless solid is a strong base (pKa of conjugate acid is 17 in H2O), which is useful in organic synthesis. The compound is often depicted as a salt, and it often behaves as such, but its ionization depends on the solvent. Preparation Potassium ''t''-butoxide is commercially available as a solution and as a solid, but it is often generated ''in situ'' for laboratory use because samples are so moisture- sensitive and older samples are often of low purity. It is prepared by the reaction of dry ''tert''-butyl alcohol with potassium metal. The solid is obtained by evaporating these solutions followed by heating the solid. The solid can be purified by sublimation. Structure It crystallizes as a tetrameric cubane-type cluster. It crystallises from tetrahydrofuran/pentane at −20 °C as BuOK·tBuOHsub>∞, which consists of straig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkoxides
In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organyl substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands. Alkoxides, although generally not stable in protic solvents such as water, occur widely as intermediates in various reactions, including the Williamson ether synthesis.excerpt Transition metal alkoxides are widely used for coatings and as catalysts. Enolates are unsaturated alkoxides derived by deprotonation of a bond adjacent to a ketone or aldehyde. The nucleophilic center for simple alkoxides is located on the oxygen, whereas the nucleophilic site on enolates is delocalized onto both carbon and oxygen sites. Ynolates are also unsaturated alkoxides derived from acetylenic alcohols. Phenoxides are close relatives of the alkoxides, in which the alkyl group is replaced by a phenyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Compounds
Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the least dense solid element. Like all alkali metals, lithium is highly reactivity (chemistry), reactive and flammable, and must be stored in vacuum, inert atmosphere, or inert liquid such as purified kerosene or mineral oil. It exhibits a metallic luster (mineralogy), luster. It corrosion, corrodes quickly in air to a dull silvery gray, then black tarnish. It does not occur freely in nature, but occurs mainly as pegmatite, pegmatitic minerals, which were once the main source of lithium. Due to its solubility as an ion, it is present in ocean water and is commonly obtained from brines. Lithium metal is isolated electrolysis, electrolytically from a mixture of lithium chloride and potassium chloride. The Atomic nucleus, nucleus of the lithiu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-nucleophilic Bases
As the name suggests, a non-nucleophilic base is a sterically hindered organic base that is a poor nucleophile. Normal bases are also nucleophiles, but often chemists seek the proton-removing ability of a base without any other functions. Typical non-nucleophilic bases are bulky, such that protons can attach to the basic center but alkylation and complexation is inhibited. Non-nucleophilic bases A variety of amines and nitrogen heterocycles are useful bases of moderate strength (pKa of conjugate acid around 10-13) * ''N'',''N''-Diisopropylethylamine (DIPEA, also called Hünig's Base), pKa = 10.75 *1,8-Diazabicycloundec-7-ene (DBU) - useful for E2 elimination reactions, pKa = 13.5 * 1,5-Diazabicyclo(4.3.0)non-5-ene (DBN) - comparable to DBU * 2,6-Di-tert-butylpyridine, a weak non-nucleophilic base pKa = 3.58 * Phosphazene bases, such as ''t''-Bu-P4''Activation in anionic polymerization: Why phosphazene bases are very exciting promoters'' S. Boileau, N. Illy Prog. Polym. Sci., 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organolithium Compounds
In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom to the substrates in synthetic steps, through nucleophilic addition or simple deprotonation. Organolithium reagents are used in industry as an initiator for anionic polymerization, which leads to the production of various elastomers. They have also been applied in asymmetric synthesis in the pharmaceutical industry. Due to the large difference in electronegativity between the carbon atom and the lithium atom, the C−Li bond is highly ionic. Owing to the polar nature of the C−Li bond, organolithium reagents are good nucleophiles and strong bases. For laboratory organic synthesis, many organolithium reagents are commercially available in solution form. These reagents are highly reactive, and are sometimes pyrophoric. History and deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
