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Acene
In organic chemistry, the acenes or polyacenes are a class of organic compounds and polycyclic aromatic hydrocarbons made up of benzene () rings which have been linearly fused. They follow the general molecular formula . The larger representatives have potential interest in optoelectronic applications and are actively researched in chemistry and electrical engineering. Pentacene has been incorporated into organic field-effect transistors, reaching charge carrier mobilities as high as 5 cm2/Vs. The first 5 unsubstituted members are listed in the following table: Hexacene is not stable in air, and dimerises upon isolation. Heptacene (and larger acenes) is very reactive and has only been isolated in a matrix. However, bis(trialkylsilylethynylated) versions of heptacene have been isolated as crystalline solids. Larger acenes Due to their increased conjugation length the larger acenes are also studied. Theoretically, a number of reports are available on longer chains u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acenes General Structure
In organic chemistry, the acenes or polyacenes are a class of organic compounds and polycyclic aromatic hydrocarbons made up of benzene () Ring (chemistry), rings which have been linearly fused-ring compound, fused. They follow the general molecular formula . The larger representatives have potential interest in optoelectronic applications and are actively researched in chemistry and electrical engineering. Pentacene has been incorporated into organic field-effect transistors, reaching charge carrier mobilities as high as 5 cm2/Vs. The first 5 unsubstituted members are listed in the following table: Hexacene is not stable in air, and Dimer (chemistry), dimerises upon isolation. Heptacene (and larger acenes) is very Reactivity (chemistry), reactive and has only been isolated in a matrix. However, bis(trialkylsilylethynylated) versions of heptacene have been isolated as crystalline solids. Larger acenes Due to their increased conjugated system, conjugation length the larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heptacene 200
Heptacene is an organic compound and a polycyclic aromatic hydrocarbon and the seventh member of the acene or polyacene family of linear fused benzene rings. This compound has long been pursued by chemists because of its potential interest in electronic applications and was first synthesized but not cleanly isolated in 2006. Heptacene was finally fully characterized in bulk by researchers in Germany and the United States in 2017. : The final step is a photochemical decarbonylization with a 1,2-dione bridge extruded as carbon monoxide. In solution heptacene is not formed because it is very unstable being a reactive DA diene and quickly reacts with oxygen or forms dimers. When on the other hand the dione precursor is dissolved in a PMMA matrix first, heptacene can be studied by spectroscopy. Heptacene has been studied spectroscopically at cryogenic temperatures in a matrix. When dissolved in sulfuric acid the heptacene dication is reported to be stable at room-temperature for more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentacene
Pentacene () is a polycyclic aromatic hydrocarbon consisting of five linearly-fused benzene () rings. This highly conjugated compound is an organic semiconductor. The compound generates excitons upon absorption of ultra-violet ( UV) or visible light; this makes it very sensitive to oxidation. For this reason, this compound, which is a purple powder, slowly degrades upon exposure to air and light. Structurally, pentacene is one of the linear acenes, the previous one being tetracene (four fused benzene rings) and the next one being hexacene (six fused benzene rings). In August 2009, a group of researchers from IBM published experimental results of imaging a single molecule of pentacene using an atomic force microscope. In July 2011, they used a modification of scanning tunneling microscopy to experimentally determine the shapes of the highest occupied and lowest unoccupied molecular orbitals. In 2012, pentacene-doped ''p''-terphenyl was shown to be effective as the amplifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentacene 200
Pentacene () is a polycyclic aromatic hydrocarbon consisting of five linearly-fused benzene () Ring (chemistry), rings. This highly Conjugation (organic chemistry), conjugated compound is an organic semiconductor. The compound generates excitons upon absorption of ultra-violet (UV) or visible light; this makes it very sensitive to oxidation. For this reason, this compound, which is a purple powder, slowly Chemical decomposition, degrades upon exposure to air and light. Structurally, pentacene is one of the linear acenes, the previous one being tetracene (four fused benzene rings) and the next one being hexacene (six fused benzene rings). In August 2009, a group of researchers from IBM published experimental results of imaging a single molecule of pentacene using an atomic force microscope. In July 2011, they used a modification of scanning tunneling microscopy to experimentally determine the shapes of the HOMO/LUMO, highest occupied and lowest unoccupied molecular Molecular orbita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, as a scintillator to detect high energy particles, as production of pharmaceutical drugs. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation. History and etymology Crude anthracene (with a melting point of only 180°) was discovered in 1832 by Jean-Baptiste Dumas and Auguste Laurent who crystalized it from a fraction of coal tar later known as "anthracene oil". Since their (inaccurate) measurements showed the proportions of carbon and hydrogen of it to be the same as in naphthalene, Laurent called it ''paranaphtaline'' in his 1835 publication of the discovery, which is translated to English as paranaphthalene. Two years later, however, he decided to rename the compound to its modern name d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexacene 200
Hexacene is an aromatic compound consisting of six linearly-fused benzene rings. It is a blue-green, air-stable solid with low solubility. Hexacene is one of a series of linear polycyclic molecules created by such aromatic ring fusions, a series termed acenes; the previous in the series is pentacene (with five fused rings) and the next is heptacene (with seven). It and other acenes and their derivatives have been investigated in potential applications related to organic semiconductors. Like larger acenes, hexacene is poorly soluble, but derivatives have been prepared with improved solubility, such as 6,15-Bis(tri-t-butylsilylethynyl)hexacene, which melts with decomposition at 96 °C. Syntheses and structure Hexacene has been the subject of many syntheses. One route uses thermal decarbonylation of a monoketone precursor. Further reading *First synthesis: **Marschalk, C. Linear hexacenes. Bull. Soc. Chim. Fr. 6, 1112–1121 (1939). ** ** *By dehydrogenation of ''hexacosahyd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetracene 200
Tetracene, also called naphthacene, is a polycyclic aromatic hydrocarbon. It has the appearance of a pale orange powder. Tetracene is the four-ringed member of the series of acenes. Tetracene is a molecular organic semiconductor, used in organic field-effect transistors (OFETs) and organic light-emitting diodes (OLEDs). Tetracene can be used as a gain medium in dye lasers as a sensitiser in chemoluminescence. Napthacene is the main component of the tetracycline class of antibiotics. History and synthesis In 1884, W. Roser attempted to synthesize a compound called "Aethindiphtalyls" (literally "ethyne diphthalyl") by heating 3 parts of phthalic anhydride, 3 parts of succinic acid and one part of sodium acetate according to Siegmund Gabriel's procedure. And then he found that there was a brick-red byproduct was produced in a large amount in the reaction, which was called "Isoäthindiphtalid" ("Isoethyne diphthalide") and founded to be an isomer of "Aethindiphtalyls". In 189 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diradical
In chemistry, a diradical is a chemical species, molecular species with two electrons occupying molecular orbitals (MOs) which are degenerate energy level, degenerate. The term "diradical" is mainly used to describe organic compounds, where most diradicals are extremely reactivity (chemistry), reactive and non-Kekulé molecules that are rarely isolated. Diradicals are even-electron molecules but have one fewer chemical bond, bond than the number permitted by the octet rule. Examples of diradical species can also be found in coordination chemistry, for example among metal dithiolene complex, bis(1,2-dithiolene) metal complexes. Spin states Diradicals are usually triplet state, triplets. The phrases ''singlet'' and ''triplet'' are derived from the multiplicity of states of diradicals in electron spin resonance: a singlet diradical has one state (S=0, Ms=2*0+1=1, ms=0) and exhibits no signal in electron paramagnetic resonance, EPR and a triplet diradical has 3 states (S=1, Ms=2*1+1= ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphene
Graphene () is a carbon allotrope consisting of a Single-layer materials, single layer of atoms arranged in a hexagonal lattice, honeycomb planar nanostructure. The name "graphene" is derived from "graphite" and the suffix -ene, indicating the presence of double bonds within the carbon structure. Graphene is known for its exceptionally high Ultimate tensile strength, tensile strength, Electrical resistivity and conductivity, electrical conductivity, Transparency and translucency, transparency, and being the thinnest two-dimensional material in the world. Despite the nearly transparent nature of a single graphene sheet, graphite (formed from stacked layers of graphene) appears black because it absorbs all visible light wavelengths. On a microscopic scale, graphene is the strongest material ever measured. The existence of graphene was first theorized in 1947 by P. R. Wallace, Philip R. Wallace during his research on graphite's electronic properties, while the term ''graphen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
