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Tetrahydroxy-1,4-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 calcium salt is the dark purple pigment produced from inositol by '' Chromohalobacter beijerinckii'' in the fermentation of salt beans, already noted by T. Hof in 1935. The dark purple and insoluble dipotassium s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromohalobacter Beijerinckii
''Chromohalobacter beijerinckii'' is a motile, rod-like, salt-loving, Gram-negative soil bacterium, 0.4–0.6 μm by 1.8–2.5 μm. The bacterium was isolated in 1935 by T. Hof from fermented salted beans preserved in brine. Hof named it ''Pseudomonas beijerinckii'' and identified it as the organism responsible for the purple color of that food. The pigment was the calcium salt of tetrahydroxy-''p''-benzoquinone Ca2C6O6, derived from the beans' ''myo''-inositol. The bacterium thrives in media with salt (NaCl) concentrations ranging from 0.35% to 25%; the optimum growth occurs at 8 to 10% NaCl, pH 7.5, and 35 °C. Janina Peçonek, Claudia Gruber, Virginia Gallego, Antonio Ventosa, Hans-Jürgen Busse, Peter Kämpfer, Christian Radax, and Helga Stan-Lotter (2006), ''Reclassification of ''Pseudomonas beijerinckii'' Hof 1935 as ''Chromohalobacter beijerinckii'' comb. nov., and emended description of the species''. International Journal of Systematic and Evolutionary Micro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Merck Index
''The Merck Index'' is an encyclopedia of chemicals, drugs and biologicals with over 10,000 monographs on single substances or groups of related compounds published online by the Royal Society of Chemistry. History The first edition of the Merck's Index was published in 1889 by the German chemical company Emanuel Merck and was primarily used as a sales catalog for Merck's growing list of chemicals it sold. The American subsidiary was established two years later and continued to publish it. During World War I the US government seized Merck's US operations and made it a separate American "Merck" company that continued to publish the Merck Index. In 2012 the Merck Index was licensed to the Royal Society of Chemistry. An online version of The Merck Index, including historic records and new updates not in the print edition, is commonly available through research libraries. It also includes an appendix with monographs on organic named reactions. The 15th edition was published in A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium
Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, which is easily removed to create cation, an ion with a positive charge (which combines with anions to form salts). In nature, potassium occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac-flame color, colored flame. It is found dissolved in seawater (which is 0.04% potassium by weight), and occurs in many minerals such as orthoclase, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium
Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the periodic table. Its only stable isotope is 23Na. The free metal does not occur in nature and must be prepared from compounds. Sodium is the Abundance of elements in Earth's crust, sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and halite (NaCl). Many salts of sodium are highly water-soluble: sodium ions have been Leaching (chemistry), leached by the action of water from the Earth, Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans. Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Among many other useful sodium compounds, sodium hydroxide (lye) is used in Soap, soap manufac ... [...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 from the hydroxyls (p''K''a1 = , p''K''a2 = at 25 °C), yielding the hydrogen rhodizonate 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 used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paramagnetic
Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. In contrast with this behavior, diamagnetic materials are repelled by magnetic fields and form induced magnetic fields in the direction opposite to that of the applied magnetic field. Paramagnetic materials include most chemical elements and some compounds; they have a relative magnetic permeability slightly greater than 1 (i.e., a small positive magnetic susceptibility) and hence are attracted to magnetic fields. The magnetic moment induced by the applied field is linear in the field strength and rather weak. It typically requires a sensitive analytical balance to detect the effect and modern measurements on paramagnetic materials are often conducted with a SQUID magnetometer. Paramagnetism is due to the presence of unpaired electrons in the material, so most atom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a light, Volatility (chemistry), volatile, colorless and flammable liquid with a distinctive alcoholic odor similar to that of ethanol (potable alcohol), but is more acutely toxic than the latter. Methanol acquired the name wood alcohol because it was once produced through destructive distillation of wood. Today, methanol is mainly produced industrially by hydrogenation of carbon monoxide. Methanol consists of a methyl group linked to a polar hydroxyl group. With more than 20 million tons produced annually, it is used as a Precursor (chemistry), precursor to other commodity chemicals, including formaldehyde, acetic acid, methyl tert-butyl ether, methyl ''tert''-butyl ether, methyl benzoate, anisole, peroxyacids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hsien Ying Niu
Xi'an or Xian (西安) is the capital of Shaanxi province, China. Xian or Xi'an may also refer to: Places *Counties of China, known in Chinese as ''xiàn'' (县/縣) * Xian (state) (弦), a minor state during the Zhou dynasty *Xian County (献县/獻縣), a county in the Cangzhou prefecture, Hebei province, China *Xi'an District, Mudanjiang (西安区), in Heilongjiang, China *Xi'an District, Liaoyuan (西安区), formerly Xi'an County, in Jilin, China *Xiān (暹), group of ancient political entities in Thailand. People * Emperor Xian (other), posthumous name of several Chinese rulers * Xian (surname) (咸; 冼), a Chinese surname * Ashina Xian, a Western Turk khagan also appointed general by the Tang dynasty *Bi Xian (802–864), official of the Chinese dynasty Tang dynasty *Dong Xian (23 BC – 1 BC), Han dynasty politician *Dou Xian (died 92 AD), Chinese general and consort kin of the Eastern Han dynasty *Luo Xian (died 270), military general of the Jin dynasty of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert West (chemist)
Robert Culbertson West Jr. (March 18, 1928 – October 12, 2022) was an American chemist. West was an E. G. Rochow Professor of Chemistry Emeritus at the University of Wisconsin–Madison; Director of the Organosilicon Research Center, University of Wisconsin–Madison 1999–20??; President, Silatronix, Inc. (2007–20??); Distinguished Professor, Yonsei University, 2007–2011. He died in Madison, Wisconsin on October 12, 2022, at the age of 94. Education West received his Bachelor of Arts in Chemistry from Cornell University in 1950, proceeding on to Harvard University where he received his Master of Arts in 1952 and Ph.D. in 1954. At Cornell, he was a member of the Quill and Dagger society. Notable work West was a chemist best known for his groundbreaking research in silicon chemistry as well as for his work with oxocarbons and organolithium compounds. In 2004, West was listed as one of the most cited scientists during the period 1981-1999, according to a citation surve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrochloric Acid
Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is a component of the gastric acid in the digestive systems of most animal species, including humans. Hydrochloric acid is an important laboratory reagent and industrial chemical. Etymology Because it was produced from halite, rock salt according to the methods of Johann Rudolph Glauber, hydrochloric acid was historically called by European alchemists ''spirits of salt'' or ''acidum salis'' (salt acid). Both names are still used, especially in other languages, such as , , , , , , , , , , (''ensan''), zh, 盐酸 (''yánsuān''), and (''yeomsan''). Gaseous HCl was called ''marine acid air''. The name ''muriatic acid'' has the same origin (''muriatic'' means "pertaining to brine or salt", hence ''muriate'' means hydrochloride), and this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Carbonate
Potassium carbonate is the inorganic compound with the formula . It is a white salt, which is soluble in water and forms a strongly alkaline solution. It is deliquescent, often appearing as a damp or wet solid. Potassium carbonate is mainly used in the production of soap and glass. Commonly, it can be found as the result of leakage of alkaline batteries. Potassium carbonate is a potassium salt of carbonic acid. This salt consists of potassium cations and carbonate anions , and is therefore an alkali metal carbonate. History Potassium carbonate is the primary component of potash and the more refined pearl ash or salt of tartar. Historically, pearl ash was created by baking potash in a kiln to remove impurities. The fine, white powder remaining was the pearl ash. The first patent issued by the US Patent Office was awarded to Samuel Hopkins in 1790 for an improved method of making potash and pearl ash. In late 18th-century North America, before the development of baking pow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
