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Tetraethylammonium Bromide
Tetraethylammonium bromide (TEAB) is a quaternary ammonium compound with the chemical formula C8H20N+Br−, often written as "Et4N+Br−" in the chemical literature. It has been used as the source of tetraethylammonium ions in pharmacological and physiological studies, but is also used in organic chemical synthesis. Chemistry Synthesis TEAB is commercially available, but can be prepared by the reaction between tetraethylammonium hydroxide and hydrobromic acid: :Et4N+HO− + HBr → Et4N+Br− + H2O Evaporation of the water and recrystallization from acetonitrile yields a crystalline sample of TEAB. Structure The crystal structure of TEAB has been determined and found to exhibit a distorted tetrahedral symmetry with respect to the geometry of the C atoms around the central N. Synthetic applications Examples include: * TEAB catalyzes the high-yield oxidation of organic sulfides to sulfoxides by o-iodoxybenzoic acid (IBX) in chloroform/water at room temperature, e.g. :(C2H5) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Ammonium Compound
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethylammonium
Tetraethylammonium (TEA), () or (Et4N+) is a quaternary ammonium cation consisting of four ethyl groups attached to a central nitrogen atom, and is positively charged. It is a counterion used in the research laboratory to prepare lipophilic salts of inorganic anions. It is used similarly to tetrabutylammonium, the difference being that its salts are less lipophilic and more easily crystallized. Preparation The chloride salt is prepared by the reaction of triethylamine and an ethyl halide: :Et3N + EtX → Et4N+X− This method works well for the preparation of tetraethylammonium iodide (where X = I). Most tetraethylammonium salts are prepared by salt metathesis reactions. For example, the synthesis of tetraethylammonium perchlorate, a salt that has been useful as a supporting electrolyte for polarographic studies in non-aqueous solvents, is carried out by mixing the water-soluble salts tetraethylammonium bromide and sodium perchlorate in water, from which the water-insoluble tet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrobromic Acid
Hydrobromic acid is a strong acid formed by dissolving the diatomic molecule hydrogen bromide (HBr) in water. "Constant boiling" hydrobromic acid is an aqueous solution that distills at and contains 47.6% HBr by mass, which is 8.77 mol/L. Hydrobromic acid has a p''K''a of −9, making it a stronger acid than hydrochloric acid, but not as strong as hydroiodic acid. Hydrobromic acid is one of the strongest mineral acids known. Uses Hydrobromic acid is mainly used for the production of inorganic bromides, especially the bromides of zinc, calcium, and sodium. It is a useful reagent for generating organobromine compounds. Certain ethers are cleaved with HBr. It also catalyzes alkylation reactions and the extraction of certain ores. Industrially significant organic compounds prepared from hydrobromic acid include allyl bromide, tetrabromobis(phenol), and bromoacetic acid. HBr almost uniquely participates in anti-Markovnikov hydrohalogenation of alkenes. The resulting 1-bro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfide (organic)
In organic chemistry, an organic sulfide (British English sulphide) or thioether is an organosulfur functional group with the connectivity as shown on right. Like many other sulfur-containing compounds, volatile sulfides have foul odors. A sulfide is similar to an ether except that it contains a sulfur atom in place of the oxygen. The grouping of oxygen and sulfur in the periodic table suggests that the chemical properties of ethers and sulfides are somewhat similar, though the extent to which this is true in practice varies depending on the application. Nomenclature Sulfides are sometimes called thioethers, especially in the old literature. The two organic substituents are indicated by the prefixes. (CH3)2S is called dimethylsulfide. Some sulfides are named by modifying the common name for the corresponding ether. For example, C6H5SCH3 is methyl phenyl sulfide, but is more commonly called thioanisole, since its structure is related to that for anisole, C6H5OCH3. The modern sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfoxides
In organic chemistry, a sulfoxide, also called a sulphoxide, is an organosulfur compound containing a sulfinyl () functional group attached to two carbon atoms. It is a polar functional group. Sulfoxides are oxidized derivatives of sulfides. Examples of important sulfoxides are alliin, a precursor to the compound that gives freshly crushed garlic its aroma, and dimethyl sulfoxide (DMSO), a common solvent. Structure and bonding Sulfoxides feature relatively short S–O distances. In DMSO, the S–O distance is 1.531 Å. The sulfur center is pyramidal; the sum of the angles at sulfur is about 306°.. Sulfoxides are generally represented with the structural formula R−S(=O)−R', where R and R' are organic groups. The bond between the sulfur and oxygen atoms is intermediate of a dative bond and a polarized double bond. The double-bond resonance form implies 10 electrons around sulfur (10-S-3 in N-X-L notation). The double-bond character of the S−O bond may be accounted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O-iodoxybenzoic Acid
2-Iodoxybenzoic acid (IBX) is an organic compound used in organic synthesis as an oxidizing agent. This periodinane is especially suited to oxidize alcohols to aldehydes. IBX is prepared from 2-iodobenzoic acid, potassium bromate, and sulfuric acid. Frigerio and co-workers have also demonstrated, in 1999 that potassium bromate may be replaced by commercially available Oxone. One of the main drawbacks of IBX is its limited solubility; IBX is insoluble in many common organic solvents. In the past, it was believed that IBX was shock sensitive, but it was later proposed that samples of IBX were shock sensitive due to the residual potassium bromate left from its preparation. Commercial IBX is stabilized by carboxylic acids such as benzoic acid and isophthalic acid. Reaction mechanism The reaction mechanism for an oxidation of an alcohol to an aldehyde according to the hypervalent twisting mechanism involves a ligand exchange reaction replacing the hydroxyl group by the alcohol follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Superoxide
Potassium superoxide is an inorganic compound with the formula KO2. It is a yellow paramagnetic solid that decomposes in moist air. It is a rare example of a stable salt of the superoxide anion. It is used as a scrubber, dehumidifier, and generator in rebreathers, spacecraft, submarines, and spacesuits. Production and reactions Potassium superoxide is produced by burning molten potassium in an atmosphere of excess oxygen. :K + → The salt consists of and ions, linked by ionic bonding. The O−O distance is 1.28 Å. Reactivity Potassium superoxide is a source of superoxide, which is a reductant and a nucleophile, depending on its reaction partner. Upon contact with water, it undergoes disproportionation to potassium hydroxide, oxygen, and hydrogen peroxide: :2 + → 2 KOH + : + → KOH + + It reacts with carbon dioxide, releasing oxygen: :2 + → K2CO3 + :2 + 2 + H2O → 2 KHCO3 + Potassium superoxide finds only niche uses as a laboratory reagent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkyl Halides
The haloalkanes (also known as halogenoalkanes or alkyl halides) are alkanes containing one or more halogen substituents. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalkanes are widely used commercially. They are used as flame retardants, fire extinguishants, refrigerants, propellants, solvents, and pharmaceuticals. Subsequent to the widespread use in commerce, many halocarbons have also been shown to be serious pollutants and toxins. For example, the chlorofluorocarbons have been shown to lead to ozone depletion. Methyl bromide is a controversial fumigant. Only haloalkanes that contain chlorine, bromine, and iodine are a threat to the ozone layer, but fluorinated volatile haloalkanes in theory may have activity as greenhouse gases. Methyl iodide, a naturally occurring substance, however, does not have ozone-depleting properties and the United States Environmental Protection Agency has designated the compound a non-ozone l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dialkyl Peroxides
In organic chemistry, organic peroxides are organic compounds containing the peroxide functional group (). If the R′ is hydrogen, the compounds are called hydroperoxides, which are discussed in that article. The O−O bond of peroxides easily breaks, producing free radicals of the form (the dot represents an unpaired electron). Thus, organic peroxides are useful as initiators for some types of polymerisation, such as the epoxy resins used in glass-reinforced plastics. MEKP and benzoyl peroxide are commonly used for this purpose. However, the same property also means that organic peroxides can explosively combust. Organic peroxides, like their inorganic counterparts, are often powerful bleaching agents. Types of organic peroxides Tert-Butyl hydroperoxide Structural Formula V2.svg, ''tert''-Butyl hydroperoxide, a hydroperoxide (formula: ROOH) that is used to epoxide alkenes. Dicumyl peroxide.svg, Dicumyl peroxide, a dialkyl peroxide (formula: ROOR) that is used to initiate po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethylammonium Chloride
Tetraethylammonium chloride (TEAC) is a quaternary ammonium compound with the chemical formula (C2H5)4N+Cl−, sometimes written as Et4N+Cl−. In appearance, it is a hygroscopic, colorless, crystalline solid. It has been used as the source of tetraethylammonium ions in pharmacological and physiological studies, but is also used in organic chemical synthesis. Preparation and structure TEAC is produced by alkylation of triethylamine with ethyl chloride. TEAC exists as either of two stable hydrates, the monohydrate and tetrahydrate. The crystal structure of TEAC.H2O has been determined, as has that of the tetrahydrate, TEAC.4H2O. Details for the preparation of large, prismatic crystals of TEAC.H2O are given by Harmon and Gabriele, who carried out IR-spectroscopic studies on this and related compounds. These researchers have also pointed out that, although freshly-purified TEAC.H2O is free of triethylamine hydrochloride, small quantities of this compound form on heating of TEAC as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethylammonium Iodide
Tetraethylammonium iodide is a quaternary ammonium compound with the chemical formula C8H20N+I−. It has been used as the source of tetraethylammonium ions in pharmacological and physiological studies, but is also used in organic chemical synthesis. Chemistry Preparation Tetraethylammonium iodide is commercially available, but can be prepared by the reaction between triethylamine and ethyl iodide. Structure The crystal structure of tetraethylammonium iodide has been determined. The crystal structure is a distorted wurtzite lattice. At the nitrogen atom, the coordination is a flattened tetrahedron. The N−C−C angle is slightly larger than the tetrahedral angle. Synthetic applications Examples include: * Stereoselective formation of (Z)-diiodoalkenes by treatment of alkynes with ICl in the presence of tetraethylammonium iodide. * 2-Hydroxyethylation (attachment of −CH2−CH2−OH) by ethylene carbonate of carboxylic acids and certain heterocycles b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethylammonium
Tetraethylammonium (TEA), () or (Et4N+) is a quaternary ammonium cation consisting of four ethyl groups attached to a central nitrogen atom, and is positively charged. It is a counterion used in the research laboratory to prepare lipophilic salts of inorganic anions. It is used similarly to tetrabutylammonium, the difference being that its salts are less lipophilic and more easily crystallized. Preparation The chloride salt is prepared by the reaction of triethylamine and an ethyl halide: :Et3N + EtX → Et4N+X− This method works well for the preparation of tetraethylammonium iodide (where X = I). Most tetraethylammonium salts are prepared by salt metathesis reactions. For example, the synthesis of tetraethylammonium perchlorate, a salt that has been useful as a supporting electrolyte for polarographic studies in non-aqueous solvents, is carried out by mixing the water-soluble salts tetraethylammonium bromide and sodium perchlorate in water, from which the water-insoluble tet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
