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Copper Chromite
Copper chromite is an inorganic compound with the formula Cu2Cr2O5. It is a black solid that is used to catalyze reactions in organic synthesis. History The material was first described in 1908. The catalyst was developed in North America by Homer Burton Adkins and Wilbur Arthur Lazier, partly based on interrogation of German chemists after World War II in relation to the Fischer–Tropsch process. For this reason it is sometimes referred to as the Adkins catalyst or the Lazier catalyst. Chemical structure The compound adopts a spinel structure. The oxidation states for the constituent metals are Cu(II) and Cr(III). A variety of compositions are recognized for the substance, including Cu2CrO4·CuO·BaCrO4 ( CAS# 99328-50-4) and Cu2Cr2O5 (CAS# 12053-18-8). Commercial samples often contain barium oxide and other components. Production Copper chromite is produced by thermal decomposition of one of three substances. The traditional method is by the ignition of copper chromate: : 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemistry''. Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep mantle remain active areas of investigation. Some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon (graphite, diamond, buckminsterfullerene, etc.), carbon monoxide, carbon dioxide, carbides, and the following salts of inorganic anions: carbonates, cyanides, cyanates, and thiocyanates. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it does not occur within living things. History Friedrich Wöhler's conversion of ammonium cyanate into urea in 1828 is often cited as the starting point of modern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper(II) Nitrate
Copper(II) nitrate describes any member of the family of inorganic compounds with the formula Cu( NO3)2(H2O)x. The hydrates are blue solids. Anhydrous copper nitrate forms blue-green crystals and sublimes in a vacuum at 150-200 °C. Common hydrates are the hemipentahydrate and trihydrate. Synthesis and reactions Hydrated copper(II) nitrate Hydrated copper nitrate is prepared by treating copper metal or its oxide with nitric acid: :Cu + 4HNO3 → Cu(NO3)2. + 2H2O + 2NO2 The same salts can be prepared treating copper metal with an aqueous solution of silver nitrate. That reaction illustrates the ability of copper metal to reduce silver ions. In aqueous solution, the hydrates exist as the aqua complex u(H2O)6sup>2+. Such complexes are highly labile owing to the d9 electronic configuration of copper(II). Attempted dehydration of any of the hydrated copper(II) nitrates by heating affords the oxides, not Cu(NO3)2. At 80 °C, the hydrates convert to "basic copper nitrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmosphere (unit)
The standard atmosphere (symbol: atm) is a unit of pressure defined as Pa. It is sometimes used as a ''reference pressure'' or ''standard pressure''. It is approximately equal to Earth's average atmospheric pressure at sea level. History The standard atmosphere was originally defined as the pressure exerted by 760 mm of mercury at and standard gravity (''g''n = ). It was used as a reference condition for physical and chemical properties, and was implicit in the definition of the Celsius temperature scale, which defined as the boiling point of water at this pressure. In 1954, the 10th General Conference on Weights and Measures (CGPM) adopted ''standard atmosphere'' for general use and affirmed its definition of being precisely equal to dynes per square centimetre (). This defined both temperature and pressure independent of the properties of particular substance. In addition, the CGPM noted that there had been some misapprehension that it "led some physicists to believe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stilbene
{{Chemistry index ...
Stilbene may refer to one of the two stereoisomers of 1,2-diphenylethene: * (''E'')-Stilbene (''trans'' isomer) * (''Z'')-Stilbene (''cis'' isomer) See also * Stilbenoids, a class of molecules found in plants * 1,1-Diphenylethylene 1,1-Diphenylethylene is an aromatic hydrocarbon with chemical formula CH. Properties 1,1-Diphenylethylene mediates the radical polymerization of methyl acrylate or styrene. Meditation by 1,1-Diphenylethylene generates low molecular weight polymer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decarboxylation
Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is called carboxylation, the addition of CO2 to a compound. Enzymes that catalyze decarboxylations are called decarboxylases or, the more formal term, carboxy-lyases (Enzyme Commission number, EC number 4.1.1). In organic chemistry The term "decarboxylation" usually means replacement of a carboxyl group () with a hydrogen atom: :RCO2H -> RH + CO2 Decarboxylation is one of the oldest known organic reactions. It is one of the processes assumed to accompany pyrolysis and destructive distillation. Metal salts, especially copper compounds, facilitate the reaction via the intermediacy of metal carboxylate complexes. Decarboxylation of aryl carboxylates can generate the equivalent of the correspond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,5-pentanediol
1,5-Pentanediol is the organic compound with the formula HOCHCHCHCHCHOH. Like other diols, this viscous colourless liquid is used as plasticizer and also forms polyesters that are used as emulsifying agents and resin intermediates. 1,5-Pentanediol is produced by hydrogenation of glutaric acid and its derivatives. It can also be prepared by hydrogenolysis of tetrahydrofurfuryl alcohol. Contamination of Bindeez A toy called ''Bindeez'' (''Aqua Dots'' in North America) was recalled by the distributor in November 2007 because of the unauthorized substitution of 1,5-pentanediol with 1,4-butanediol. The toy consists of small beads that stick to each other upon sprinkling with water. 1,4-Butanediol, which when ingested is metabolized to gamma-hydroxybutyric acid ''gamma''-Hydroxybutyric acid (or γ-hydroxybutyric acid (GHB), also known as 4-hydroxybutanoic acid) is a naturally occurring neurotransmitter and a depressant drug. It is a precursor to GABA, glutamate, and glycine in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahydrofurfuryl Alcohol
Tetrahydrofurfuryl alcohol (THFA) is an organic compound with the formula HOCH2C4H7O. In terms of its structure, it consists of a tetrahydrofuran ring substituted in the 2-position with a hydroxymethyl group. It is a colorless liquid that is used as a specialty solvent and synthetic intermediate, e.g. to 3,4-dihydropyran. It is prepared by hydrogenation of furfural. It is a precursor to 1,5-pentanediol. Other uses THFA is often used in epoxy resin formulations in either the epoxy component or amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituen ... hardener as well as other general resin applications.{{Cite web, title=Natural Resins Products THFA, url=https://www.silvateam.com/en/products-and-services/natural-resins/tetrahydrofurfuryl-alcohol.html, date=2022, website=SilvaTea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenanthrene
Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) with formula C14H10, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics and pesticides, explosives and drugs. It has also been used to make bile acids, cholesterol and steroids. Phenanthrene occurs naturally and also is a man-made chemical. Commonly, humans are exposed to phenanthrene through inhalation of cigarette smoke but there are many routes of exposure. Animal studies have shown that phenanthrene is a potential carcinogen. However, according to IARC, it is not identified as a probable, possible or confirmed human carcinogen. Phenanthrene's three fused rings are angled as in the phenacenes, rather than straight as in the acenes. The compound with a phenanthrene skeleton and nitrogens at the 4 and 5 positions is known as phenanthroline. Chemistry Phenanthrene is nearly insoluble in water but is soluble in most low pola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sebacic Acid
Sebacic acid is a naturally occurring dicarboxylic acid with the chemical formula . It is a white flake or powdered solid. ''Sebaceus'' is Latin for tallow candle, ''sebum'' is Latin for tallow, and refers to its use in the manufacture of candles. Sebacic acid is a derivative of castor oil. In the industrial setting, sebacic acid and its homologues such as azelaic acid can be used as a monomer for nylon 610, plasticizers, lubricants, hydraulic fluids, cosmetics, candles, etc. Production Sebacic acid is produced from castor oil by cleavage of ricinoleic acid, which is obtained from castor oil. Octanol & glycerin is a byproduct. It can also be obtained from decalin via the tertiary hydroperoxide, which gives cyclodecenone, a precursor to sebacic acid. Potential medical significance Sebum is a secretion by skin sebaceous glands. It is a waxy set of lipids composed of triglycerides (≈41%), wax esters (≈26%), squalene (≈12%), and free fatty acids (≈16%). Included in the fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acyloin Condensation
Acyloin condensation is a reductive coupling of two carboxylic esters using metallic sodium to yield an α-hydroxyketone, also known as an acyloin. The reaction is most successful when ''R'' is aliphatic and saturated. The reaction is performed in aprotic solvents with a high boiling point, such as benzene and toluene in an oxygen free atmosphere of nitrogen (as even traces of oxygen interfere with the reaction path and reduce the yield). The use of protic solvents results in the Bouveault-Blanc reduction of the separate esters rather than condensation. Depending on ring size and steric properties, but independent from high dilution, the acyloin condensation of diesters favours intramolecular cyclisation over intermolecular polymerisation when diesters are used (see below). To account for such cyclisation, it is suggested that the ends, where ester groups are present, are adsorbed, albeit weakly, at nearby sites on the sodium metal. Thus, the reactive ends are not available f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcohol (chemistry)
In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl () functional group bound to a saturated carbon atom. The term ''alcohol'' originally referred to the primary alcohol ethanol (ethyl alcohol), which is used as a drug and is the main alcohol present in alcoholic drinks. An important class of alcohols, of which methanol and ethanol are the simplest examples, includes all compounds which conform to the general formula . Simple monoalcohols that are the subject of this article include primary (), secondary () and tertiary () alcohols. The suffix ''-ol'' appears in the IUPAC chemical name of all substances where the hydroxyl group is the functional group with the highest priority. When a higher priority group is present in the compound, the prefix ''hydroxy-'' is used in its IUPAC name. The suffix ''-ol'' in non-IUPAC names (such as paracetamol or cholesterol) also typically indicates that the substance is an alcohol. However, some compou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
