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Acenes
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 using ... [...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 () 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 us ... [...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] |
Heptacene
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] |
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 Economic production, 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+[anthracene]− (M = Li, Na, K). Hydrogenation gives 9 ... [...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 being pentacene (with five fused rings) and the next being 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. 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 entails by thermal decarbonylation of monoketone precursor. Further reading *First synthesis: **Marschalk, C. Linear hexacenes. Bull. Soc. Chim. Fr. 6, 1112–1121 (1939). ** ** *By dehydrogenation of ''hexacos ... [...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] |
Hexacene
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 being pentacene (with five fused rings) and the next being 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. 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 entails by thermal decarbonylation of monoketone precursor. Further reading *First synthesis: **Marschalk, C. Linear hexacenes. Bull. Soc. Chim. Fr. 6, 1112–1121 (1939). ** ** *By dehydrogenation of ''hexacosa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentacene 200
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] |
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). In May 2007, researchers from two Japanese universities, Tohoku University in Sendai and Osaka University, reported an ambipolar light-emitting transistor made of a single tetracene crystal. Ambipolar means that the electric charge is transported by both positively charged holes and negatively charged electrons. Tetracene can be also used as a gain medium in dye lasers as a sensitiser in chemoluminescence. Jan Hendrik Schön during his time at Bell Labs (1997–2002) claimed to have developed an electrically pumped laser based on tetracene. However, his results could not be reproduced, and this is considered to be a scientific fraud. Napthacene is the main ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetracene
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). In May 2007, researchers from two Japanese universities, Tohoku University in Sendai and Osaka University, reported an ambipolar light-emitting transistor made of a single tetracene crystal. Ambipolar means that the electric charge is transported by both positively charged holes and negatively charged electrons. Tetracene can be also used as a gain medium in dye lasers as a sensitiser in chemoluminescence. Jan Hendrik Schön during his time at Bell Labs (1997–2002) claimed to have developed an electrically pumped laser based on tetracene. However, his results could not be reproduced, and this is considered to be a scientific fraud. Napthacene is the main back ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diradical
In chemistry, a diradical is a molecular species with two electrons occupying molecular orbitals (MOs) which are degenerate. The term "diradical" is mainly used to describe organic compounds, where most diradicals are extremely reactive and in fact rarely isolated. Diradicals are even-electron molecules but have one fewer bond than the number permitted by the octet rule. Examples of diradical species can also be found in coordination chemistry, for example among bis(1,2-dithiolene) metal complexes. Spin states Diradicals are usually 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 EPR and a triplet diradical has 3 states (S = 1, Ms = 2*1+1 = 3, ms = -1; 0; 1) and shows in EPR 2 peaks (if no hyperfine splitting). The triplet state has total spin quantum number S = 1 and is paramagnetic. Therefore, di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphene
Graphene () is an allotrope of carbon consisting of a single layer of atoms arranged in a hexagonal lattice nanostructure. "Carbon nanostructures for electromagnetic shielding applications", Mohammed Arif Poothanari, Sabu Thomas, et al., ''Industrial Applications of Nanomaterials'', 2019. "Carbon nanostructures include various low-dimensional allotropes of carbon including carbon black (CB), carbon fiber, carbon nanotubes (CNTs), fullerene, and graphene." The name is derived from "graphite" and the suffix -ene, reflecting the fact that the allotrope of carbon contains numerous double bonds. Each atom in a graphene sheet is connecte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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