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Sodium Hypobromite
Sodium hypobromite is an inorganic compound with the chemical formula . It is a sodium salt of hypobromous acid. It consists of sodium cations and hypobromite anions . It is usually obtained as the pentahydrate, so the compound that is usually called sodium hypobromite actually has the formula . It is a yellow-orange solid that is soluble in water. It adopts a monoclinic crystal structure with a Br–O bond length of 1.820 Å. It is the bromine analogue of sodium hypochlorite, the active ingredient in common bleach. In practice the salt is usually encountered as an aqueous solution. Sodium hypobromite arises by treatment of aqueous solution of bromine with base: : It can be prepared ''in situ'' for use as a reagent, such as in the synthesis of 3-aminopyridine from nicotinamide (Hofmann rearrangement). : Sodium hypobromite slowly disproportionates to sodium bromide and sodium bromate Sodium bromate, the inorganic compound with the chemical formula of NaBrO3, is the sodium sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Bromide
Sodium bromide is an inorganic compound with the formula . It is a high-melting white, crystalline solid that resembles sodium chloride. It is a widely used source of the bromide ion and has many applications.Michael J. Dagani, Henry J. Barda, Theodore J. Benya, David C. Sanders "Bromine Compounds" in ''Ullmann's Encyclopedia of Industrial Chemistry'' Wiley-VCH, Weinheim, 2000. Synthesis, structure, reactions NaBr crystallizes in the same cubic motif as NaCl, NaF and NaI. The anhydrous salt crystallizes above 50.7 °C. Dihydrate salt () crystallize out of water solution below 50.7 °C. NaBr is produced by treating sodium hydroxide with hydrogen bromide. Sodium bromide can be used as a source of the chemical element bromine. This can be accomplished by treating an aqueous solution of NaBr with chlorine gas: : Applications Sodium bromide is the most useful inorganic bromide in industry. It is also used as a catalyst in TEMPO-mediated oxidation reactions. Medici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromine
Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name was derived , referring to its sharp and pungent smell. Elemental bromine is very reactive and thus does not occur as a free element in nature. Instead, it can be isolated from colourless soluble crystalline mineral halide Ionic salt, salts analogous to table salt, a property it shares with the other halogens. While it is rather rare in the Earth's crust, the high solubility of the bromide ion (Br) has caused its Bromine cycle, accumulation in the oceans. Commercially the element is easily extracted from brine evaporation ponds, mostly in the United States and Israel. The mass of bromine in the oce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Bromate
Sodium bromate, the inorganic compound with the chemical formula of NaBrO3, is the sodium salt of bromic acid. It is a strong oxidant. Uses Sodium bromate is mainly used in continuous or batch dyeing processes involving sulfur or vat dyes and as a hair-permagent, chemical agent, or gold solvent in gold mines when used with sodium bromide. Production Sodium bromate can be produced from a solution of sodium carbonate and bromine using chlorine gas as the oxidising agent. : It may also be produced by the electrolytic oxidation of aqueous sodium bromide. Human health issues Bromate in drinking water is undesirable because it is a suspected human carcinogen. Its presence in Coca-Cola's Dasani Dasani () is a brand of bottled water created by the Coca-Cola Company, launched in 1999. It is one of many List of Coca-Cola brands, brands of Coca-Cola bottled water sold around the world. The product is filtered and bottled. Marketing Un ... bottled water forced a recall of tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Bromide
Sodium bromide is an inorganic compound with the formula . It is a high-melting white, crystalline solid that resembles sodium chloride. It is a widely used source of the bromide ion and has many applications.Michael J. Dagani, Henry J. Barda, Theodore J. Benya, David C. Sanders "Bromine Compounds" in ''Ullmann's Encyclopedia of Industrial Chemistry'' Wiley-VCH, Weinheim, 2000. Synthesis, structure, reactions NaBr crystallizes in the same cubic motif as NaCl, NaF and NaI. The anhydrous salt crystallizes above 50.7 °C. Dihydrate salt () crystallize out of water solution below 50.7 °C. NaBr is produced by treating sodium hydroxide with hydrogen bromide. Sodium bromide can be used as a source of the chemical element bromine. This can be accomplished by treating an aqueous solution of NaBr with chlorine gas: : Applications Sodium bromide is the most useful inorganic bromide in industry. It is also used as a catalyst in TEMPO-mediated oxidation reactions. Medici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disproportionation
In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation state. The reverse of disproportionation, such as when a compound in an intermediate oxidation state is formed from precursors of lower and higher oxidation states, is called ''comproportionation'', also known as ''symproportionation''. More generally, the term can be applied to any desymmetrizing reaction where two molecules of one type react to give one each of two different types: : This expanded definition is not limited to redox reactions, but also includes some molecular autoionization reactions, such as the self-ionization of water. In contrast, some authors use the term ''redistribution'' to refer to reactions of this type (in either direction) when only ligand exchange but no redox is involved and distinguish such processes from disproportionation and comproportionati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthesis Of 3-Aminopyridine
Synthesis or synthesize may refer to: Science Chemistry and biochemistry *Chemical synthesis, the execution of chemical reactions to form a more complex molecule from chemical precursors **Organic synthesis, the chemical synthesis of organic compounds ***Total synthesis, the complete organic synthesis of complex organic compounds, usually without the aid of biological processes ***Convergent synthesis or linear synthesis, a strategy to improve the efficiency of multi-step chemical syntheses **Dehydration synthesis, a chemical synthesis resulting in the loss of a water molecule *Biosynthesis, the creation of an organic compound in a living organism, usually aided by enzymes **Photosynthesis, a biochemical reaction using a carbon molecule to produce an organic molecule, using sunlight as a catalyst **Chemosynthesis, the synthesis of biological compounds into organic waste, using methane or an oxidized molecule as a catalyst **Amino acid synthesis, the synthesis of an amino acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hofmann Rearrangement
The Hofmann rearrangement (Hofmann degradation) is the organic reaction of a primary amide to a primary amine with one less carbon atom. The reaction involves oxidation of the nitrogen followed by rearrangement of the carbonyl and nitrogen to give an isocyanate intermediate. The reaction can form a wide range of products, including alkyl and aryl amines. The reaction is named after its discoverer, August Wilhelm von Hofmann, and should not be confused with the Hofmann elimination, another name reaction for which he is eponymous. Mechanism The reaction of bromine with sodium hydroxide forms sodium hypobromite ''in situ'', which transforms the primary amide into an intermediate isocyanate. The formation of an intermediate nitrene is not possible because it implies also the formation of a hydroxamic acid as a byproduct, which has never been observed. The intermediate isocyanate is hydrolyzed to a primary amine, giving off carbon dioxide. #Base abstracts an acidic N-H proto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide
Nicotinamide (International nonproprietary name, INN, British Approved Name, BAN ) or niacinamide (United States Adopted Name, USAN ) is a form of vitamin B3, vitamin B3 found in food and used as a dietary supplement and medication. As a supplement, it is used oral administration, orally (swallowed by mouth) to prevent and treat pellagra (niacin deficiency). While nicotinic acid (niacin) may be used for this purpose, nicotinamide has the benefit of not causing Flushing (physiology), skin flushing. As a cream, it is used to treat acne, and has been observed in clinical studies to improve the appearance of aging skin by reducing hyperpigmentation and redness. It is a Water-soluble vitamins, water-soluble vitamin. Side effects are minimal. At high doses, liver problems may occur. Normal amounts are safe for use during pregnancy. Nicotinamide is in the vitamin B family of medications, specifically the vitamin B3 complex, vitamin B3 complex. It is an amide of nicotinic acid. Foods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-aminopyridine
3-Aminopyridine is an aminopyridine. It is a colorless solid. Preparation 3-Aminopyridine is prepared by heating nicotinamide with sodium hypobromite ( Hofmann rearrangement), which is in turn prepared ''in situ'' by the reaction of sodium hydroxide and bromine at 70 °C. : It can be used in the synthesis of organic ligand 3-pyridylnicotinamide. Troxipide is another synthesis that uses 3-AP. Toxicity The acute toxicity is indicated by the LD50 In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a given substance. The value of LD50 for a substance is the dose requ ... = 178 mg/kg (quail, oral). References {{DEFAULTSORT:Aminopyridine, 3- 3-Aminopyridines 3-Pyridyl compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reagent
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a substance ''consumed'' in the course of a chemical reaction. ''Solvents'', though involved in the reaction mechanism, are usually not called reactants. Similarly, ''catalysts'' are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates. Definitions Organic chemistry In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents. Analytical chemistry In analytical chemistry, a reag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Press
Academic Press (AP) is an academic book publisher founded in 1941. It launched a British division in the 1950s. Academic Press was acquired by Harcourt, Brace & World in 1969. Reed Elsevier said in 2000 it would buy Harcourt, a deal completed the next year, after a regulatory review. Thus, Academic Press is now an imprint of Elsevier. Academic Press publishes reference books, serials and online products in the subject areas of: * Communications engineering * Economics * Environmental science * Finance * Food science and nutrition * Geophysics * Life sciences * Mathematics and statistics * Neuroscience * Physical sciences * Psychology Psychology is the scientific study of mind and behavior. Its subject matter includes the behavior of humans and nonhumans, both consciousness, conscious and Unconscious mind, unconscious phenomena, and mental processes such as thoughts, feel ... Well-known products include the '' Methods in Enzymology'' series and encyclopedias such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base (chemistry)
In chemistry, there are three definitions in common use of the word "base": '' Arrhenius bases'', '' Brønsted bases'', and '' Lewis bases''. All definitions agree that bases are substances that react with acid An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...s, as originally proposed by Guillaume-François Rouelle, G.-F. Rouelle in the mid-18th century. In 1884, Svante Arrhenius proposed that a base is a substance which dissociates in aqueous solution to form hydroxide ions OH−. These ions can react with Hydron (chemistry), hydrogen ions (H+ according to Arrhenius) from the dissociation of acids to form water in an acid–base reaction. A base was therefore a metal hydroxide such as NaOH or Calcium hydroxide, Ca(OH)2. Such aqueous hydroxide solutions were also described by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
