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Benzenehexol
Benzenehexol, also called hexahydroxybenzene, is an organic compound with formula or . It is a six-fold phenol of benzene. The product is also called hexaphenol, but this name has been used also for other substances. Benzenehexol is a crystalline solid soluble in hot water, with a melting point above 310°. It can be prepared from inositol (cyclohexanehexol). Oxidation of benzenehexol yields tetrahydroxy-''p''-benzoquinone (THBQ), rhodizonic acid, and dodecahydroxycyclohexane. Conversely, benzenehexol can be obtained by reduction of sodium THBQ salt with SnCl2/ HCl. Benzenehexol is a starting material for a class of discotic liquid crystals. Benzenehexol forms an adduct with 2,2'-bipyridine, with 1:2 molecular ratio. Benzenehexolate Like most phenols, benzenehexol can lose the six H+ ions from the hydroxyl groups, yielding the hexaanion . The potassium salt of this anion is one of the components of Liebig's so-called "potassium carbonyl", the product of the reaction of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodizonic Acid
Rhodizonic acid is a chemical compound with formula or . It can be seen as a twofold enol and fourfold ketone of cyclohexene, more precisely 5,6-dihydroxycyclohex-5-ene-1,2,3,4-tetrone. Rhodizonic acid is usually obtained in the form of a dihydrate . The latter is actually 2,3,5,5,6,6-hexahydroxycyclohex-2-ene-1,4-dione, where two of the original ketone groups are replaced by two pairs of geminal diols. The orange to deep-red and highly hygroscopic anhydrous acid can be obtained by low-pressure sublimation of the dihydrate. Like many other enols, rhodizonic acid can lose the hydrogen cations H+ from the hydroxyls (p''K''a1 = , p''K''a2 = at 25 °C), yielding the hydrogenrhodizonate anion and the rhodizonate anion . The latter is aromatic and symmetric, as the double bond and the negative charges are delocalized and evenly distributed over the six CO units. Rhodizonates tend to have various shades of red, from yellowish to purplish. Rhodizonic acid has been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Monoxide
Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simplest molecule of the oxocarbon family. In coordination complexes the carbon monoxide ligand is called carbonyl. It is a key ingredient in many processes in industrial chemistry. The most common source of carbon monoxide is the partial combustion of carbon-containing compounds, when insufficient oxygen or heat is present to produce carbon dioxide. There are also numerous environmental and biological sources that generate and emit a significant amount of carbon monoxide. It is important in the production of many compounds, including drugs, fragrances, and fuels. Upon emission into the atmosphere, carbon monoxide affects several processes that contribute to climate change. Carbon monoxide has important biological roles across phylogenetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahydroxy-p-benzoquinone
Tetrahydroxy-1,4-benzoquinone, also called tetrahydroxy-''p''-benzoquinone, tetrahydroxybenzoquinone, or tetrahydroxyquinone (THBQ, THQ), is an organic compound with formula . Its molecular structure consists of a cyclohexadiene ring with four hydroxyl groups and two ketone groups in opposite (''para'') positions. The compound gives a light red solution in water, and crystallizes as the glistening bluish-black (but non-conducting) dihydrate . The compound can be synthesized from glyoxal or from ''myo''-inositol, a natural compound widely present in plants. THBQ forms an adduct with 4,4′-bipyridine in a 2:3 ratio. Salts of THBQ Like most phenols, THBQ is acidic and easily loses the four hydrogen ions from the hydroxyl groups, yielding anions such as and . The latter is symmetric and aromatic, as the double bonds and negative charges are evenly distributed over the six CO groups. The calcium salt is the dark purple pigment produced from inositol by '' Chromohalobacter beije ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dodecahydroxycyclohexane
Dodecahydroxycyclohexane is an organic compound with molecular formula or or . It is a sixfold geminal diol with a cyclohexane backbone and can be regarded as a sixfold hydrate of cyclohexanehexone (). Dihydrate The dihydrate can be crystallized from methanol as colorless plates or prisms, that decomposes at about 100 °C. This compound was synthesized by J. Lerch in 1862 by oxidation of benzenehexol or tetrahydroxy-''p''-benzoquinone and characterized by R. Nietzki and others in 1885, although the product was for a long time assumed to be hexaketocyclohexane with water of crystallization (). Indeed, this product is still commonly marketed as cyclohexanehexone octahydrate, hexaketocyclohexane octahydrate, triquinoyl octahydrate and similar names. Its true nature was suspected since the 1950s or earlier, but was confirmed by X-ray diffraction analysis only in 2005. See also *Decahydroxycyclopentane Decahydroxycyclopentane is an organic compound with formula or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylenediolate
Acetylenediol, or ethynediol, is a chemical substance with formula HO−C≡C−OH (an ynol). It is the diol of acetylene. Acetylenediol is unstable in the condensed phase, although its tautomer glyoxal (CHO)2 is well known. Detection Acetylenediol was first observed in the gas-phase by mass spectrometry. The compound was later obtained by photolysis of squaric acid in a solid argon matrix at . Derivatives Alkoxide derivatives Like the diol, most simple ether derivatives are labile. Di-tert-butoxyacetylene is however a distillable liquid. Acetylenediolate salts Salts of the acetylenediolate (ethynediolate) dianion −O−C≡C−O− are known. They are not however prepared from ethynediol, but by the reduction of carbon monoxide. Potassium acetylenediolate (K2C2O2) was first obtained by Liebig in 1834, from the reaction of carbon monoxide with metallic potassium;Justus Liebig (1834), Annalen der Chemie und Pharmacie, volume 11, p. 182. Cited by Raymond N. Vrtis et al. ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Chemistry
The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemistry, chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, and the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 34,000 in the UK and a further 8,000 abroad. The headquarters of the Society are at Burlington House, Piccadilly, London. It also has offices in Thomas Graham House in Cambridge (named after Thomas Graham (chemist), Thomas Graham, the first president of the Chemical Society) where ''RSC Publishing'' is based. The Society has offices in the United States, on the campuses of The University of Pennsylvania and Drexel University, at the University City Science Center in Philadelphia, Pennsylvania, in both Beijing a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion , called hydroxide, and the neutral radical , known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term ''hydroxyl'' refers to the hydroxyl radical () only, while the functional group is called a ''hydroxy group''. Properties Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack this f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Battery
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell. Primary (single-use or "disposable") batteries are used once and discarded, as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery used f ... [...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] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the substance and w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Justus Von Liebig
Justus Freiherr von Liebig (12 May 1803 – 20 April 1873) was a German scientist who made major contributions to agricultural and biological chemistry, and is considered one of the principal founders of organic chemistry. As a professor at the University of Giessen, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the greatest chemistry teachers of all time. He has been described as the "father of the fertilizer industry" for his emphasis on nitrogen and trace minerals as essential plant nutrients, and his formulation of the law of the minimum, which described how plant growth relied on the scarcest nutrient resource, rather than the total amount of resources available. He also developed a manufacturing process for beef extracts, and with his consent a company, called Liebig Extract of Meat Company, was founded to exploit the concept; it later introduced the Oxo brand beef bouillon cube. He popularized an earlier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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