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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] |
The Merck Index
''The Merck Index'' is an encyclopedia of chemicals, drugs and biologicals with over 10,000 monograph 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 Apr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bean
A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food. They can be cooked in many different ways, including boiling, frying, and baking, and are used in many traditional dishes throughout the world. Terminology The word "bean" and its Germanic cognates (e.g. German '' Bohne'') have existed in common use in West Germanic languages since before the 12th century, referring to broad beans, chickpeas, and other pod-borne seeds. This was long before the New World genus '' Phaseolus'' was known in Europe. After Columbian-era contact between Europe and the Americas, use of the word was extended to pod-borne seeds of ''Phaseolus'', such as the common bean and the runner bean, and the related genus ''Vigna''. The term has long been applied generally to many other seeds of similar form, such as Old World soybeans, peas, other vetches, and lupins, and even to those with slighter resemblances, such as coffee beans, vanilla ... [...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] |
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 atoms wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a light, volatile, colourless, flammable liquid with a distinctive alcoholic odour similar to that of ethanol (potable alcohol). A polar solvent, methanol acquired the name wood alcohol because it was once produced chiefly by the 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 to other commodity chemicals, including formaldehyde, acetic acid, methyl tert-butyl ether, methyl benzoate, anisole, peroxyacids, as well as a host of more specialised chemicals. Occurrence Small amounts of methanol are present in normal, healthy hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methoxide
In organic chemistry, methoxides are organic salts with a anion. They are the simplest alkoxides. Sodium methoxide and potassium methoxide have widespread use, though other metal-cation variants such as lithium methoxide, rubidium methoxide, and caesium methoxide exist as well. Methoxide ion The methoxide ion has the formula of CH3O− and is the conjugate base of methanol. It is a strong organic base, and since it is stronger than the inorganic hydroxide ion, it can remove a hydrogen atom from a water molecule, yielding methanol and hydroxide. Therefore, methoxide solutions must be kept free of water. Sodium methoxide Sodium methoxide, also called sodium methylate and sodium methanolate, is a white powder when pure. It is used as an initiator of an anionic addition polymerization with ethylene oxide, forming a polyether with high molecular weight. Both sodium methoxide and its counterpart prepared with potassium are frequently used as catalysts for commercial-sc ... [...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 People *Xian (surname) (咸; 冼), a Chinese surname *Xian (video game player) or Ho Kun Xian (born 1990), Singaporean fighting games player * Emperor Xian (other), posthumous name of several Chinese rulers *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 BCE(?) – 1 BCE), Han Dynasty politician *Dou Xian (died 92 AD), Chinese general and consort kin of the Eastern Han Dynasty *Luo Xian (died 270), military ge ... [...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, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid Acid strength is the tendency of an acid, symbolised by the chemical formula HA, to dissociate into a proton, H+, and an anion, A-. The dissociation of a strong acid in solution is effectively complete, except in its most concentrated solutions .... 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. History In the early tenth century, the Persian physician and alchemist Abu Bakr al-Razi ( 865–925, Latin: Rhazes) conducted experiments with sal ammoniac (ammonium chloride) and vitriol (hydrated sulfates of various metals), which he distilled together, thus producing the gas hydrogen chloride. In doing so, al-Razi may have stumbled upon a primitive method ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Carbonate
Potassium carbonate is the inorganic compound with the formula K2 CO3. It is a white salt, which is soluble in water. It is deliquescent, often appearing as a damp or wet solid. Potassium carbonate is mainly used in the production of soap and glass. History Potassium carbonate is the primary component of potash and the more refined pearl ash or salts 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 powder, pearl ash was used as a leavening agent for quick breads. Production Potassium carbonate is prepared commercially by the reaction potassium hydroxide with carbon dioxide: : 2 KOH + CO2 → K2CO3 + H2O From the solution crystallizes the sesquihydrate K2CO3·H2O ("potash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitric Acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% , it is referred to as ''fuming nitric acid''. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. Nitric acid is also commonly used as a strong oxidizing agen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inositol
Inositol, or more precisely ''myo''-inositol, is a carbocyclic sugar that is abundant in the brain and other mammalian tissues; it mediates cell signal transduction in response to a variety of hormones, neurotransmitters, and growth factors and participates in osmoregulation. It is a sugar alcohol with half the sweetness of sucrose (table sugar). It is made naturally in the human body from glucose. A human kidney makes about two grams per day. Other tissues synthesize it too, and the highest concentration is in the brain, where it plays an important role by making other neurotransmitters and some steroid hormones bind to their receptors. Inositol is promoted as a dietary supplement in the management of polycystic ovary syndrome (PCOS). However, there is only evidence of very low quality for its efficacy in increasing fertility for IVF in women with PCOS. Overview ''myo''-Inositol plays an important role as the structural basis for a number of secondary messengers in eukaryotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
