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Anthracene
Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Anthracene is used in the production of the red dye alizarin and other dyes. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation. Occurrence and production Coal tar, which contains around 1.5% anthracene, remains a major source of this material. Common impurities are phenanthrene and carbazole. The mineral form of anthracene is called freitalite and is related to a coal deposit. A classic laboratory method for the preparation of anthracene is by cyclodehydration of o-methyl- or o-methylene-substituted diarylketones in the so-called Elbs reaction, for example from ''o''-tolyl phenyl ketone. Reactions Reduction Reduction of anthracene with alkali metals yields the deeply colored radical anion salts M+ nthracenesup>− (M = Li, Na, K). Hydrogenation gives 9,10- dihydroant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthracene Singlet Oxygen Diels-Alder Reaction
Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Anthracene is used in the production of the red dye alizarin and other dyes. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation. Occurrence and production Coal tar, which contains around 1.5% anthracene, remains a major source of this material. Common impurities are phenanthrene and carbazole. The mineral form of anthracene is called freitalite and is related to a coal deposit. A classic laboratory method for the preparation of anthracene is by cyclodehydration of o-methyl- or o-methylene-substituted diarylketones in the so-called Elbs reaction, for example from ''o''-tolyl phenyl ketone. Reactions Reduction Reduction of anthracene with alkali metals yields the deeply colored radical anion salts M+ nthracenesup>− (M = Li, Na, K). Hydrogenation gives 9,10- dihydroanth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthracene Photodimerisation
Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Anthracene is used in the production of the red dye alizarin and other dyes. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation. Occurrence and production Coal tar, which contains around 1.5% anthracene, remains a major source of this material. Common impurities are phenanthrene and carbazole. The mineral form of anthracene is called freitalite and is related to a coal deposit. A classic laboratory method for the preparation of anthracene is by cyclodehydration of o-methyl- or o-methylene-substituted diarylketones in the so-called Elbs reaction, for example from ''o''-tolyl phenyl ketone. Reactions Reduction Reduction of anthracene with alkali metals yields the deeply colored radical anion salts M+ nthracenesup>− (M = Li, Na, K). Hydrogenation gives 9,10- dihydroanth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycyclic Aromatic Hydrocarbon
A polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. The simplest representative is naphthalene, having two aromatic rings and the three-ring compounds anthracene and phenanthrene. PAHs are uncharged, non-polar and planar. Many are colorless. Many of them are found in coal and in oil deposits, and are also produced by the combustion of organic matter—for example, in engines and incinerators or when biomass burns in forest fires. Polycyclic aromatic hydrocarbons are discussed as possible starting materials for abiotic syntheses of materials required by the earliest forms of life. Nomenclature and structure The terms polyaromatic hydrocarbon or polynuclear aromatic hydrocarbon are also used for this concept. By definition, polycyclic aromatic hydrocarbons have multiple rings, precluding benzene from being considered a PAH. Some sources, such as the US EPA and CDC, consider naphthalene to be the simplest PAH. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alizarin
Alizarin (also known as 1,2-dihydroxyanthraquinone, Mordant Red 11, C.I. 58000, and Turkey Red) is an organic compound with formula that has been used throughout history as a prominent red dye, principally for dyeing textile fabrics. Historically it was derived from the roots of plants of the madder genus.The primary madder species from which alizarin historically has been obtained is ''Rubia tinctorum''. See also In 1869, it became the first natural dye to be produced synthetically. Alizarin is the main ingredient for the manufacture of the madder lake pigments known to painters as rose madder and alizarin crimson. Alizarin in the most common usage of the term has a deep red color, but the term is also part of the name for several related non-red dyes, such as Alizarine Cyanine Green and Alizarine Brilliant Blue. A notable use of alizarin in modern times is as a staining agent in biological research because it stains free calcium and certain calcium compounds a red or ligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinone Acsv
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein the keto groups are located on the central ring. It is a building block of many dyes and is used in bleaching pulp for papermaking. It is a yellow, highly crystalline solid, poorly soluble in water but soluble in hot organic solvents. It is almost completely insoluble in ethanol near room temperature but 2.25 g will dissolve in 100 g of boiling ethanol. It is found in nature as the rare mineral hoelite. Synthesis There are several current industrial methods to produce 9,10-anthraquinone: # The oxidation of anthracene. Chromium(VI) is the typical oxidant. # The Friedel-Crafts reaction of benzene and phthalic anhydride in presence of AlCl3. o-Benzoylbenzoic acid is an intermediate. This reaction is useful for produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinone
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein the keto groups are located on the central ring. It is a building block of many dyes and is used in bleaching pulp for papermaking. It is a yellow, highly crystalline solid, poorly soluble in water but soluble in hot organic solvents. It is almost completely insoluble in ethanol near room temperature but 2.25 g will dissolve in 100 g of boiling ethanol. It is found in nature as the rare mineral hoelite. Synthesis There are several current industrial methods to produce 9,10-anthraquinone: # The oxidation of anthracene. Chromium(VI) is the typical oxidant. # The Friedel-Crafts reaction of benzene and phthalic anhydride in presence of AlCl3. o-Benzoylbenzoic acid is an intermediate. This reaction is useful for produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydroanthracene
9,10-Dihydroanthracene is an organic compound that is derived from the polycyclic aromatic hydrocarbon anthracene. Several isomers of dihydroanthracene are known, but the 9,10 derivative is most common. It is a colourless solid that is used as a carrier of H2 as a hydrogen-donor. Preparation Because the aromaticity is not compromised for the flanking rings, anthracene is susceptible to hydrogenation at the 9- and 10- positions. It is produced in the laboratory by dissolving metal reduction using sodium/ethanol, an application of the Bouveault–Blanc reduction developed by Louis Bouveault and Gustave Louis Blanc in 1903. The reduction can be effected by magnesium as well. Finally, it can also be prepared by the coupling of benzyl chloride using aluminium chloride as a catalyst. The bond dissociation energy The bond-dissociation energy (BDE, ''D''0, or ''DH°'') is one measure of the strength of a chemical bond . It can be defined as the standard enthalpy change when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
9-Anthracenecarboxaldehyde
Anthracene-9-carbaldehyde is the most common monoaldehyde derivative of anthracene. It is a yellow solid that is soluble in common organic solvents. It is prepared by Vilsmeier formylation of anthracene. The compound is also used as a building block for supramolecular assemblies. 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 reduce or saturate organ ... of 9-anthracenecarboxaldehyde gives 9-anthracenemethanol. References Aromatic aldehydes Anthracenes {{Hydrocarbon-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescence
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, than the absorbed radiation. A perceptible example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the electromagnetic spectrum (invisible to the human eye), while the emitted light is in the visible region; this gives the fluorescent substance a distinct color that can only be seen when the substance has been exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after. Fluorescence has many practical applications, including mineralogy, gemology, medicine, chemical sensors (fluorescence spectroscopy), fluorescent labelling, dyes, biological detectors, cosmic-ray detection, vac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescence Of Anthracene Under UV Light
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, than the absorbed radiation. A perceptible example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the electromagnetic spectrum (invisible to the human eye), while the emitted light is in the visible region; this gives the fluorescent substance a distinct color that can only be seen when the substance has been exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after. Fluorescence has many practical applications, including mineralogy, gemology, medicine, chemical sensors (fluorescence spectroscopy), fluorescent labelling, dyes, biological detectors, cosmic-ray detection, vac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal Tar
Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It is a type of creosote. It has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psoriasis and seborrheic dermatitis (dandruff). It may be used in combination with ultraviolet light therapy. Industrially it is a railroad tie preservative and used in the surfacing of roads. Coal tar was listed as a known human carcinogen in the first Report on Carcinogens from the U.S. Federal Government. Coal tar was discovered circa 1665 and used for medical purposes as early as the 1800s. Circa 1850, the discovery that it could be used as the main ingredient in synthetic dyes engendered an entire industry. It is on the World Health Organization's List of Essential Medicines. Coal tar is available as a generic medication and over the counter. Side effects include skin irritation, sun sensitivity, allergic reactions, and skin discolorat ... [...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 po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
