|
Acetophenones
Acetophenone is the organic compound with the formula C6H5C(O)CH3. It is the simplest aromatic ketone. This colorless, viscous liquid is a precursor to useful resins and fragrances. Production Acetophenone is formed as a byproduct of the cumene process, the industrial route for the synthesis of phenol and acetone. In the Hock rearrangement of isopropylbenzene hydroperoxide, migration of a methyl group rather than the phenyl group gives acetophenone and methanol as a result of an alternate rearrangement of the intermediate: : The cumene process is conducted on such a large scale that even the small amount of acetophenone by-product can be recovered in commercially useful quantities. Acetophenone is also generated from ethylbenzene hydroperoxide. Ethylbenzene hydroperoxide is primarily converted to 1-phenylethanol (α-methylbenzyl alcohol) in the process with a small amount of by-product acetophenone. Acetophenone is recovered or hydrogenated to 1-phenylethanol which is then deh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Chemistry
The Royal Society of Chemistry (RSC) is a learned society and professional association in the United Kingdom with the goal of "advancing the chemistry, chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, and the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 49,000 in the world. The headquarters of the Society are at Burlington House, Piccadilly, London. It also has offices in Thomas Graham House in Cambridge (named after Thomas Graham (chemist), Thomas Graham, the first president of the Chemical Society) where ''RSC Publishing'' is based. The Society has offices in the United States, on the campuses of The University of Pennsylvania and Drexel University, at the University City Science Center in Philadelphia, Pennsylvania, in both Beijing and Shanghai, People' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyol
In organic chemistry, a polyol is an organic compound containing multiple hydroxyl groups (). The term "polyol" can have slightly different meanings depending on whether it is used in food science or polymer chemistry. Polyols containing two, three and four hydroxyl groups are diols, triols, and tetrols, respectively. Classification Polyols may be classified according to their chemistry. Some of these chemistries are polyether, polyester, polycarbonate and also acrylic polyols. Polyether polyols may be further subdivided and classified as polyethylene oxide or polyethylene glycol (PEG), polypropylene glycol (PPG) and Polytetrahydrofuran or PTMEG. These have 2, 3 and 4 carbons respectively per oxygen atom in the repeat unit. Polycaprolactone polyols are also commercially available. There is also an increasing trend to use biobased (and hence renewable) polyols. Uses Polyether polyols have numerous uses. As an example, polyurethane foam is a big user of polyether polyols. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper Chromite
Copper chromite often refers to inorganic compounds with the formula . They are black solids. is a well-defined material. The other copper chromite often is described as . It is used to catalyze reactions in organic chemistry. History Copper chromite was first described in 1908. The catalyst was further developed 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. Adkins was the first to incorporate barium into the structure, which prevents the catalyst from being reduced to an inactive form during hydrogenation reactions. Chemical structures The stoichiometry of the Laziar or Adkins catalyst is not well defined, thus the structure of their material is not defined either. The oxidation states for the constituent metals in Cu2Cr2O4 are Cu(II) and Cr(III). A variety of compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogenation
Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to redox, reduce or Saturated and unsaturated compounds, saturate organic compounds. Hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule, often an alkene. Catalysts are required for the reaction to be usable; non-catalytic hydrogenation takes place only at very high temperatures. Hydrogenation reduces Double bond, double and Triple bond, triple bonds in hydrocarbons. Process Hydrogenation has three components, the Saturated and unsaturated compounds, unsaturated substrate, the hydrogen (or hydrogen source) and, invariably, a catalyst. The redox, reduction reaction is carried out at different temperatures and pressures depending upon the substrate and the activity of the catalyst. Related or competing reactions The same cataly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dehydration Reaction
In chemistry, a dehydration reaction is a chemical reaction that involves the loss of an H2O from the reacting molecule(s) or ion(s). This reaction results in the release of the H2O as water. When the reaction involves the coupling of two molecules into a single molecule it is referred to as a condensation reaction. Dehydration reactions are common processes in the manufacture of chemical compounds as well as naturally occurring within living organisms. The reverse of a dehydration reaction is called a hydration reaction. The reverse of a condensation reaction yielding water is called hydrolysis. Condensation reactions occurring in living organisms Condensation dehydration reactions are fundamental to the existence of life as this type of reaction produces proteins from amino acids, DNA and RNA from nucleotides, fats from fatty acids, and polysaccharides (eg. cellulose, starch, sugar, lactose) from monosaccharides (eg. glucose and fructose). The formation of the pyrophosphat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Borohydride
Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, is an inorganic compound with the formula (sometimes written as ). It is a white crystalline solid, usually encountered as an aqueous basic solution. Sodium borohydride is a reducing agent that finds application in papermaking and dye industries. It is also used as a reagent in organic synthesis. The compound was discovered in the 1940s by H. I. Schlesinger, who led a team seeking volatile uranium compounds.Hermann I Schlesinger and Herbert C Brown (1945)Preparation of alkali metal compounds. US Patent 2461661. Granted on 1949-02-15; expired on 1966-02-15. Results of this wartime research were declassified and published in 1953. Properties The compound is soluble in alcohols, certain ethers, and water, although it slowly hydrolyzes. Sodium borohydride is an odorless white to gray-white microcrystalline powder that often forms lumps. It can be purified by recrystallization from warm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Styrene
Styrene is an organic compound with the chemical formula C6H5CH=CH2. Its structure consists of a vinyl group as substituent on benzene. Styrene is a colorless, oily liquid, although aged samples can appear yellowish. The compound evaporates easily and has a sweet smell, although high concentrations have a less pleasant odor. Styrene is the precursor to polystyrene and several copolymers, and is typically made from benzene for this purpose. Approximately 25 million tonnes of styrene were produced in 2010, increasing to around 35 million tonnes by 2018. Natural occurrence Styrene is named after storax balsam (often commercially sold as ''styrax''), the resin of Liquidambar trees of the Altingiaceae plant family. Styrene occurs naturally in small quantities in some plants and foods (cinnamon, coffee beans, balsam tree (other), balsam trees and peanuts) and is also found in coal tar. History In 1839, the German apothecary Eduard Simon isolated a volatile liquid from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excipient
An excipient is a substance formulated alongside the active ingredient of a medication. They may be used to enhance the active ingredient’s therapeutic properties; to facilitate drug absorption; to reduce viscosity; to enhance solubility; to improve long-term stabilization (preventing denaturation and aggregation during the expected shelf life); or to add bulk to solid formulations that have small amounts of potent active ingredients (in that context, they are often referred to as "bulking agents", "fillers", or "diluents"). During the manufacturing process, excipients can improve the handling of active substances and facilitate powder flow. The choice of excipients depends on factors such as the intended route of administration, the dosage form, and compatibility with the active ingredient. Virtually all marketed drugs contain excipients, and final drug formulations commonly contain more excipient than active ingredient. Pharmaceutical regulations and standards mandate the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strawberry
The garden strawberry (or simply strawberry; ''Fragaria × ananassa'') is a widely grown Hybrid (biology), hybrid plant cultivated worldwide for its fruit. The genus ''Fragaria'', the strawberries, is in the rose family, Rosaceae. The fruit is appreciated for its aroma, bright red colour, juicy texture, and sweetness. It is eaten either fresh or in prepared foods such as fruit preserves, jam, ice cream, and chocolates. Artificial strawberry flavourings and aromas are widely used in commercial products. Botanically, the strawberry is not a berry (botany), berry, but an aggregate fruit, aggregate accessory fruit, accessory fruit. Each apparent 'seed' on the outside of the strawberry is actually an achene, a botanical fruit with a seed inside it. The garden strawberry was first bred in Brittany, France, in the 1750s via a cross of ''Virginia strawberry, F. virginiana'' from eastern North America and ''Fragaria chiloensis, F. chiloensis'', which was brought from Chile by Amédé ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jasmine
Jasmine (botanical name: ''Jasminum'', pronounced ) is a genus of shrubs and vines in the olive family of Oleaceae. It contains around 200 species native to tropical and warm temperate regions of Eurasia, Africa, and Oceania. Jasmines are widely cultivated for the characteristic fragrance of their flowers. The village of Shubra Beloula in Egypt grows most of the jasmine used by the global perfume industry. Description Jasmine can be either deciduous or evergreen, and can be erect, spreading, or climbing shrubs and vines. The leaves are borne in opposing or alternating arrangement and can be of simple, trifoliate, or pinnate formation. The flowers are typically around in diameter. They are white or yellow, although in rare instances they can be slightly reddish. The flowers are borne in cymose clusters with a minimum of three flowers, though they can also be solitary on the ends of branchlets. Each flower has about four to nine petals, two locules, and one to four ovu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honeysuckle
Honeysuckles are arching shrubs or Vine#Twining vines, twining vines in the genus ''Lonicera'' () of the family Caprifoliaceae. The genus includes 158 species native to northern latitudes in North America, Eurasia, and North Africa. Widely known species include ''Lonicera periclymenum'' (common honeysuckle or woodbine), ''Lonicera japonica'' (Japanese honeysuckle, white honeysuckle, or Chinese honeysuckle) and ''Lonicera sempervirens'' (coral honeysuckle, trumpet honeysuckle, or woodbine honeysuckle). ''L. japonica'' is a highly invasive species considered a significant pest in parts of North America, Europe, South America, New Zealand, Australia, and Africa. Some species are highly fragrant and colorful, so are cultivated as ornamental garden plants. In North America, hummingbirds are attracted to the flowers, especially ''L. sempervirens'' and ''L. ciliosa'' (orange honeysuckle). Honeysuckle derives its name from the edible sweet nectar obtainable from its tubular flowers. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cherry
A cherry is the fruit of many plants of the genus ''Prunus'', and is a fleshy drupe (stone fruit). Commercial cherries are obtained from cultivars of several species, such as the sweet '' Prunus avium'' and the sour '' Prunus cerasus''. The name 'cherry' also refers to the cherry tree and its wood, and is sometimes applied to almonds and visually similar flowering trees in the genus ''Prunus'', as in " ornamental cherry" or " cherry blossom". Wild cherry may refer to any of the cherry species growing outside cultivation, although ''Prunus avium'' is often referred to specifically by the name "wild cherry" in the British Isles. Botany True cherries ''Prunus'' subg. ''Cerasus'' contains species that are typically called cherries. They are known as true cherries and distinguished by having a single winter bud per axil, by having the flowers in small corymbs or umbels of several together (occasionally solitary, e.g. ''P. serrula''; some species with short racemes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
