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Dicyclohexylamine
Dicyclohexylamine is a secondary amine with the chemical formula HN(C6H11)2. It is a colorless liquid, although commercial samples can appear yellow. It has a fishy odor, typical for amines. It is sparingly soluble in water. As an amine, it is an organic base and useful precursor to other chemicals.Karsten Eller, Erhard Henkes, Roland Rossbacher, Hartmut Höke "Amines, Aliphatic". In ''Ullmann's Encyclopedia of Industrial Chemistry'', 2000, Wiley-VCH, Weinheim. Synthesis Dicyclohexylamine, as a mixture with cyclohexylamine, is prepared by the catalytic hydrogenation of aniline (phenylamine), with a catalyst of ruthenium and/or palladium. This method produces mainly cyclohexylamine with little dicyclohexylamine. Better results have been reported when the catalyst is applied to a support of niobic acid and/or tantalic acid. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulcanization Accelerator
Sulfur vulcanization is a chemical process for converting natural rubber or related polymers into materials of varying hardness, elasticity, and mechanical durability by heating them with sulfur or sulfur-containing compounds. Sulfur forms cross-linking bridges between sections of polymer chains which affects the mechanical and electronic properties. Many products are made with vulcanized rubber, including tires, shoe soles, hoses, and conveyor belts. The term is derived from Vulcan, the Roman god of fire. The main polymers subjected to sulfur vulcanization are polyisoprene (natural rubber, NR), polybutadiene rubber (BR) and styrene-butadiene rubber (SBR), and ethylene propylene diene monomer rubber ( EPDM rubber). All of these materials contain alkene groups adjacent to methylene groups. Other specialty rubbers may also be vulcanized, such as nitrile rubber (NBR) and butyl rubber (IIR). Vulcanization, in common with the curing of other thermosetting polymers, is generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Formula
The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are possibly arranged in the real three-dimensional space. The chemical bonding within the molecule is also shown, either explicitly or implicitly. Unlike other chemical formula types, which have a limited number of symbols and are capable of only limited descriptive power, structural formulas provide a more complete geometric representation of the molecular structure. For example, many chemical compounds exist in different isomeric forms, which have different enantiomeric structures but the same molecular formula. There are multiple types of ways to draw these structural formulas such as: Lewis Structures, condensed formulas, skeletal formulas, Newman projections, Cyclohexane conformations, Haworth projections, and Fischer projections. Several systematic chemical naming formats, as in chemical databases, are used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oral Administration
Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are intended to have a systemic effect, reaching different parts of the body via the bloodstream, for example. Oral administration can be easier and less painful than other routes, such as injection. However, the onset of action is relatively low, and the effectiveness is reduced if it is not absorbed properly in the digestive system, or if it is broken down by digestive enzymes before it can reach the bloodstream. Some medications may cause gastrointestinal side effects, such as nausea or vomiting, when taken orally. Oral administration can also only be applied to conscious patients, and patients willing and able to swallow. Terminology ''Per os'' (; ''P.O.'') is an adverbial phrase meaning literally from Latin "through the mouth" or "by mouth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 substituent such as an alkyl or aryl group (these may respectively be called alkylamines and arylamines; amines in which both types of substituent are attached to one nitrogen atom may be called alkylarylamines). Important amines include amino acids, biogenic amines, trimethylamine, and aniline; Inorganic derivatives of ammonia are also called amines, such as monochloramine (). The substituent is called an amino group. Compounds with a nitrogen atom attached to a carbonyl group, thus having the structure , are called amides and have different chemical properties from amines. Classification of amines Amines can be classified according to the nature and number of substituents on nitrogen. Aliphatic amines contain only H and alkyl substituents. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base (chemistry)
In chemistry, there are three definitions in common use of the word base, known as Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances that react with acids, as originally proposed by 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 hydrogen ions (H+ according to Arrhenius) from the dissociation of acids to form water in an acid–base reaction An acid–base reaction is a chemical reaction that occurs between an acid and a base. It can be used to determine pH via titration. Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their applica .... A base was therefore a metal hydroxide such as Sodium hydroxide, NaOH or Calcium hydroxide, Ca(OH)2. Such aqueous hydroxide solutions were also described by certain characteristic properties. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclohexylamine
Cyclohexylamine is an organic compound, belonging to the aliphatic amine class. It is a colorless liquid, although, like many amines, samples are often colored due to contaminants. It has a fishy odor and is miscible with water. Like other amines, it is a weak base, compared to strong bases such as NaOH, but it is a stronger base than its aromatic analog, aniline. It is a useful intermediate in the production of many other organic compounds (e.g. cyclamate) Preparation Cyclohexylamine is produced by two routes, the main one being the complete hydrogenation of aniline using some cobalt- or nickel-based catalysts: :C6H5NH2 + 3 H2 → C6H11NH2 It is also prepared by alkylation of ammonia using cyclohexanol. Applications left, Cyclamate, a derivative of cyclohexylamine, is a popular artificial sweetener. Cyclohexylamine is used as an intermediate in synthesis of other organic compounds. It is the precursor to sulfenamide-based reagents used as accelerator (chemistry), accelerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalyst
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aniline
Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine In organic chemistry, an aromatic amine is an organic compound consisting of an aromatic ring attached to an amine. It is a broad class of compounds that encompasses aniline Aniline is an organic compound with the formula C6 H5 NH2. Consi .... It is an industrially significant Commodity chemicals, commodity chemical, as well as a versatile starting material for fine chemical synthesis. Its main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals. Like most volatile amines, it has the odor of rotten fish. It Combustion, ignites readily, burning with a smoky flame characteristic of aromatic compounds. It is toxic to humans. Relative to benzene, it is electron-rich. It thus participates more rapidly in electrophilic aromatic substitution reactions. Likewise, it is also prone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruthenium
Ruthenium is a chemical element with the Symbol (chemistry), symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemicals. Russian-born scientist of Baltic-German ancestry Karl Ernst Claus discovered the element in 1844 at Kazan State University and named ruthenium in honor of Russian Empire, Russia. Ruthenium is usually found as a minor component of platinum ores; the annual production has risen from about 19 tonnes in 2009Summary. Ruthenium platinum.matthey.com, p. 9 (2009) to some 35.5 tonnes in 2017. Most ruthenium produced is used in wear-resistant electrical contacts and thick-film resistors. A minor application for ruthenium is in platinu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palladium
Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). They have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. More than half the supply of palladium and its congener platinum is used in catalytic converters, which convert as much as 90% of the harmful gases in automobile exhaust (hydrocarbons, carbon monoxide, and nitrogen dioxide) into nontoxic substances (nitrogen, carbon dioxide and water vapor). Palladium is also used in electronics, dentistry, medicine, hydrogen purification, chemical applications, groundwate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reductive Amination
Reductive amination (also known as reductive alkylation) is a form of amination that involves the conversion of a carbonyl group to an amine via an intermediate imine. The carbonyl group is most commonly a ketone or an aldehyde. It is considered the most important way to make amines, and a majority of amines made in the pharmaceutical industry are made this way. Reaction process In this organic reaction, the amine first reacts with the carbonyl group to form a hemiaminal species, which subsequently loses one molecule of water in a reversible manner by alkylimino-de-oxo-bisubstitution, to form the imine. The equilibrium between aldehyde/ketone and imine can be shifted toward imine formation by removal of the formed water through physical or chemical means. This intermediate imine can then be isolated and reduced with a suitable reducing agent (e.g., sodium borohydride). This method is sometimes called indirect reductive amination. In a separate approach, imine formation and redu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclohexanone
Cyclohexanone is the organic compound with the formula (CH2)5CO. The molecule consists of six-carbon cyclic molecule with a ketone functional group. This colorless oily liquid has an odor reminiscent of acetone. Over time, samples of cyclohexanone assume a pale yellow color. Cyclohexanone is slightly soluble in water and miscible with common organic solvents. Billions of kilograms are produced annually, mainly as a precursor to nylon. Production Cyclohexanone is produced by the oxidation of cyclohexane in air, typically using cobalt catalysts: :C6H12 + O2 → (CH2)5CO + H2O This process forms cyclohexanol as a by-product, and this mixture, called "KA Oil" for ketone-alcohol oil, is the main feedstock for the production of adipic acid. The oxidation involves radicals and the hydroperoxide C6H11O2H as an intermediate. In some cases, purified cyclohexanol, obtained by hydration of cyclohexene, is the precursor. Alternatively, cyclohexanone can be produced by the partial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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