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1-Tetralone
1-Tetralone is a bicyclic aromatic hydrocarbon and a ketone. In terms of its structure, it can also be regarded as benzo-fused cyclohexanone. It is a colorless oil with a faint odor. It is used as starting material for agricultural and pharmaceutical agents. The carbon skeleton of 1-tetralone is found in natural products such as Aristelegone A (4,7-dimethyl-6-methoxy-1-tetralone) from the family of Aristolochiaceae used in traditional Chinese medicine. Preparation By oxidation of 1,2,3,4-tetrahydronaphthalene As already described in 1933 by Heinrich Hock, 1,2,3,4-tetrahydronaphthalene tends to autoxidize and gradually forms the 1-hydroperoxide with atmospheric oxygen. The heavy metal ion catalyzed air oxidation of 1,2,3,4-tetrahydronaphthalene with Cr3+ or Cu2+ in the liquid phase leads via the hydroperoxide to a mixture of the intermediate 1-tetralol and the final product 1-tetralone. The boiling points of the main component 1-tetralone (255-257 °C) and the min ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners (toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemical synt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to 45% of the world's food and fertilizers. Around 70% of ammonia is used to make fertilisers in various forms and composition, such as urea and Diammonium phosphate. Ammonia in pure form is also applied directly into the soil. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical products and is used in many commercial cleaning products. It is mainly collected by downward displacement of both air and water. Although common in nature—both terrestrially and in the outer planets of the Solar System—and in wide use, ammonia is both caust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium
Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and flammable, and must be stored in vacuum, inert atmosphere, or inert liquid such as purified kerosene or mineral oil. When cut, it exhibits a metallic luster, but moist air corrodes it quickly to a dull silvery gray, then black tarnish. It never occurs freely in nature, but only in (usually ionic) compounds, such as 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 electrolytically from a mixture of lithium chloride and potassium chloride. The nucleus of the lithium atom verges on instability, since the two stable lithium isotopes foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birch Reduction
The Birch reduction is an organic reaction that is used to convert arenes to cyclohexadienes. The reaction is named after the Australian chemist Arthur Birch and involves the organic reduction of aromatic rings in an amine solvent (traditionally liquid ammonia) with an alkali metal (traditionally sodium) and a proton source (traditionally an alcohol). Unlike catalytic hydrogenation, Birch reduction does not reduce the aromatic ring all the way to a cyclohexane. An example is the reduction of naphthalene in ammonia and ethanol: Reaction mechanism and regioselectivity A solution of sodium in liquid ammonia consists of the intensely blue electride salt a(NH3)xsup>+ e−. The solvated electrons add to the aromatic ring to give a radical anion, which then abstracts a proton from the alcohol. The process then repeats at either the ''ortho'' or ''para'' position (depending on substituents) to give the final diene. The residual double bonds do not stabilize further radical add ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexafluoroisopropanol
Hexafluoroisopropanol, commonly abbreviated HFIP, is the organic compound with the formula (CF3)2CHOH. This fluoroalcohol finds use as solvent and synthetic intermediate. It appears as a colorless, volatile liquid that is characterized by a strong, pungent odor. As a solvent hexafluoro-2-propanol is polar and exhibits strong hydrogen bonding properties enabling it to dissolve substances that serve as hydrogen-bond acceptors, such as amides and ethers. (CF3)2CHOH is classified as a hard Lewis acid and its acceptor properties are discussed in the ECW model. Its relative acceptor strength toward a series of bases, versus other Lewis acids, can be illustrated by C-B plots. Dual XH–π interaction of HFIP with arenes has been found (benzene/HFIP, 7.22 kcal/mol) even stronger than the hydrogen bond in a water dimer (5-6 kcal/mol). Hexafluoro-2-propanol is transparent to UV light with high density, low viscosity and low refractive index. Production and uses Hexafluoro-propan-2-ol i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen-bonding
In chemistry, a hydrogen bond (or H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing a lone pair of electrons—the hydrogen bond acceptor (Ac). Such an interacting system is generally denoted , where the solid line denotes a polar covalent bond, and the dotted or dashed line indicates the hydrogen bond. The most frequent donor and acceptor atoms are the second-row elements nitrogen (N), oxygen (O), and fluorine (F). Hydrogen bonds can be intermolecular (occurring between separate molecules) or intramolecular (occurring among parts of the same molecule). The energy of a hydrogen bond depends on the geometry, the environment, and the nature of the specific donor and acceptor atoms and can vary between 1 and 40 kcal/mol. This makes them somewhat stronger than a van der Waals interaction, and weaker than fully covalent or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Donating Group
In chemistry, electron-rich is jargon that is used in multiple related meanings with either or both kinetic and thermodynamic implications: *with regards to electron-transfer, electron-rich species have low ionization energy and/or are reducing agents. Tetrakis(dimethylamino)ethylene is an electron-rich alkene because, unlike ethylene, it forms isolable radical cation. In contrast, electron-poor alkene tetracyanoethylene is an electron acceptor, forming isolable anions. *with regards to acid-base reactions, electron-rich species have high pKa's and react with weak Lewis acids. *with regards to nucleophilic substitution reactions, electron-rich species are relatively strong nucleophiles, as judged by rates of attack by electrophiles. For example, compared to benzene, pyrrole is more rapidly attacked by electrophiles. Pyrrole is therefore considered to be an electron-rich aromatic ring. Similarly, benzene derivatives with electron-donating groups (EDGs) are attacked by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tin(IV) Chloride
Tin(IV) chloride, also known as tin tetrachloride or stannic chloride, is an inorganic compound with the formula Sn Cl4. It is a colorless hygroscopic liquid, which fumes on contact with air. It is used as a precursor to other tin compounds. It was first discovered by Andreas Libavius (1550–1616) and was known as ''spiritus fumans libavii''. Preparation It is prepared from reaction of chlorine gas with tin at . : Sn + 2 Cl2 → SnCl4 Structure Anhydrous tin(IV) chloride solidifies at −33 °C to give monoclinic crystals with the P21/c space group. It is isostructural with SnBr4. The molecules adopt near-perfect tetrahedral symmetry with average Sn–Cl distances of 227.9(3) pm. Reactions Tin(IV) chloride is well known as a Lewis acid. Thus it forms hydrates. The pentahydrate SnCl4·5H2O was formerly known as butter of tin. They all consist of nCl4(H2O)2molecules together with varying amounts of water of crystallization. The additional water molecules link together ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Chloride
In organic chemistry, an acyl chloride (or acid chloride) is an organic compound with the functional group . Their formula is usually written , where R is a side chain. They are reactive derivatives of carboxylic acids (). A specific example of an acyl chloride is acetyl chloride, . Acyl chlorides are the most important subset of acyl halides. Nomenclature Where the acyl chloride moiety takes priority, acyl chlorides are named by taking the name of the parent carboxylic acid, and substituting ''-yl chloride'' for ''-ic acid''. Thus: : : When other functional groups take priority, acyl chlorides are considered prefixes — ''chlorocarbonyl-'': : Properties Lacking the ability to form hydrogen bonds, acyl chlorides have lower boiling and melting points than similar carboxylic acids. For example, acetic acid boils at 118 °C, whereas acetyl chloride boils at 51 °C. Like most carbonyl compounds, infrared spectroscopy reveals a band near 1750 cm−1. The simplest s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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