|
Heterocumulene
A heterocumulene is a molecule or ion containing a chain of at least three double bonds between consecutive atoms, in which one or more atoms in the doubly bonded chain is a heteroatom. Such species are analogous to a cumulene in which the chain of doubly bonded atoms contains only carbon, except that at least one carbon is replaced by a heteroatom. Some authors relax the definition to include species with chains of only two double bonds between consecutive atoms, also known as '' heteroallenes''. Because of the double bond rule, heterocumulenes are rarely isolated. Instead they tend to polymerize. Many are however common in the interstellar medium, where they exist as a dilute gas. Most of the longer ones are very unstable and reactive, and thus have a transient existence, or can only survive when dilute or in an inert matrix. Molecular clouds in space are very dilute and allow heterocumulenes to exist long enough to be detected. Some simple heterocumulenes are common chemicals or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricarbon Monoxide
Tricarbon monoxide C3O is a reactive radical oxocarbon molecule found in space, and which can be made as a transient substance in the laboratory. It can be trapped in an inert gas matrix or made as a short lived gas. C3O can be classified as a ketene or an oxocumulene a kind of heterocumulene. Natural occurrence C3O has been detected by its microwave spectrum in the dark cold Taurus Molecular Cloud One and also in the protostar Elias 18. The route to produce this is speculated to be: :HC + CO2 → HC3O+ + CO :HC3O+ → C3O + H+ or :C2 + CO → C3O which is more favourable at lower temperatures. The related C3S is more abundant in dark molecular clouds, even though oxygen is 20 times more common than sulfur. The difference is due to the higher rate of formation and that C3S is less polar. Production C3O can be produced by heating Meldrum's acid. This also produces acetone, carbon monoxide and carbon dioxide. R. L. DeKock and W. Waltner were the first to identify C3O by re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumulene
In organic chemistry, a cumulene is a compound having three or more ''cumulative'' (consecutive) double bonds. They are analogous to allenes, only having a more extensive chain. The simplest molecule in this class is butatriene (), which is also called simply ''cumulene''. Unlike most alkanes and alkenes, cumulenes tend to be rigid, comparable to polyynes. Cumulene carbenes for ''n'' from 3 to 6 have been observed in interstellar molecular clouds and in laboratory experiments by using microwave and infrared spectroscopy. (The more stable cumulenes are difficult to detect optically because they lack an electric dipole moment.) Cumulenes containing heteroatoms are called heterocumulenes; an example is carbon suboxide. Synthesis The first reported synthesis of a butatriene is that of tetraphenylbutatriene in 1921. The most common synthetic method for butatriene synthesis is based on reductive coupling of a geminal dihalovinylidene. Tetraphenylbutatriene was reported synthesized ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Suboxide
Carbon suboxide, or tricarbon dioxide, is an organic, oxygen-containing chemical compound with formula and structure . Its four cumulative double bonds make it a cumulene. It is one of the stable members of the series of linear oxocarbons , which also includes carbon dioxide () and pentacarbon dioxide (). Although if carefully purified it can exist at room temperature in the dark without decomposing, it will polymerize under certain conditions. The substance was discovered in 1873 by Benjamin Brodie by subjecting carbon monoxide to an electric current. He claimed that the product was part of a series of "oxycarbons" with formulas , namely , , , , …, and to have identified the last two; however, only is known. In 1891 Marcellin Berthelot observed that heating pure carbon monoxide at about 550 °C created small amounts of carbon dioxide but no trace of carbon, and assumed that a carbon-rich oxide was created instead, which he named "sub-oxide". He assumed it was the same ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricarbon Monosulfide
Tricarbon monosulfide (C3S) or tricarbon sulfur is a reactive molecular substance that has been detected in outer space. Tricarbon monosulfide is a heterocumulene or thiocumulene, consisting of a straight chain of three carbon atoms and a terminal sulfur atom. Properties The dipole moment of tricarbon monosulfide is 3.704 debye. The bond lengths are 1.275 Å, for terminal C=C bond, 1.292 Å for internal bond, and 1.535 Å for the C=S bond. The similar bond lengths between the carbon atoms indicate they each have a double bond nature. The rotational constants for 12C12C12C32S are B0 = 2890.38000 MHz and D0 = 0.00022416. There is a characteristic infrared absorption band at 2047.5 cm−1 due to stretching of a C=C bond. Formation Along with the related dicarbon monosulfide (CCS), tricarbon monosulfide was made by a glow discharge though carbon disulfide vapour in helium. Microwave emission lines from rotational transitions matched up with previously unkno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Star
A carbon star (C-type star) is typically an asymptotic giant branch star, a luminous red giant, whose atmosphere contains more carbon than oxygen. The two elements combine in the upper layers of the star, forming carbon monoxide, which consumes most of the oxygen in the atmosphere, leaving carbon atoms free to form other carbon compounds, giving the star a "sooty" atmosphere and a strikingly ruby red appearance. There are also some dwarf and supergiant carbon stars, with the more common giant stars sometimes being called classical carbon stars to distinguish them. In most stars (such as the Sun), the atmosphere is richer in oxygen than carbon. Ordinary stars not exhibiting the characteristics of carbon stars but cool enough to form carbon monoxide are therefore called oxygen-rich stars. Carbon stars have quite distinctive spectral characteristics, and they were first recognized by their spectra by Angelo Secchi in the 1860s, a pioneering time in astronomical spectroscopy. Spectra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicarbon Monoxide
Dicarbon monoxide (C2O) is a molecule that contains two carbon atoms and one oxygen atom. It is a linear molecule that, because of its simplicity, is of interest in a variety of areas. It is, however, so extremely reactive that it is not encountered in everyday life. It is classified as a cumulene and an oxocarbon. Occurrence Dicarbon monoxide is a product of the photolysis of carbon suboxide: :C3O2 → CO + C2O It is stable enough to observe reactions with NO and NO2. Called ketenylidene in organometallic chemistry, it is a ligand observed in metal carbonyl clusters, e.g. C2Co3(CO)9sup>+. Ketenylidenes are proposed as intermediates in the chain growth mechanism of the Fischer-Tropsch Process, which converts carbon monoxide and hydrogen to hydrocarbon fuels. The organophosphorus compound Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the envi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicyanoacetylene
Dicyanoacetylene, also called carbon subnitride or but-2-ynedinitrile (IUPAC), is a compound of carbon and nitrogen with chemical formula . It has a linear molecular structure, (often abbreviated as ), with alternating triple and single covalent bonds. It can be viewed as acetylene with the two hydrogen atoms replaced by cyanide groups. At room temperature, dicyanoacetylene is a clear liquid. Because of its high endothermic heat of formation, it can explode to carbon powder and nitrogen gas, and it burns in oxygen with a bright blue-white flame at a temperature of 5260 K (4990 °C, 9010 °F), the hottest flame in oxygen; burnt in ozone at high pressure the flame temperature exceeds 6000 K (5730 °C, 10340 °F). Synthesis Dicyanoacetylene can be prepared by passing nitrogen gas over a sample of graphite heated to temperatures between 2673 and 3000 K. As a reagent in organic chemistry Dicyanoacetylene is a powerful dienophile because the cyanide group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanoethynyl Radical
In organic chemistry, a polyyne () is any organic compound with alternating single and triple bonds; that is, a series of consecutive alkynes, with ''n'' greater than 1. These compounds are also called polyacetylenes, especially in the natural products and chemical ecology literature, even though this nomenclature more properly refers to acetylene polymers composed of alternating single and double bonds with ''n'' greater than 1. They are also sometimes referred to as oligoynes, or carbinoids after "carbyne" , the hypothetical allotrope of carbon that would be the ultimate member of the series. In ''Avancés récentes en chimie des acétylènes – Recent advances in acetylene chemistry'' The synthesis of this substance has been claimed several times since the 1960s, but those reports have been disputed. Indeed, the substances identified as short chains of "carbyne" in many early organic synthesis attempts would be called polyynes today. The simplest polyyne is diacetylene o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanogen
Cyanogen is the chemical compound with the formula ( C N)2. It is a colorless and highly toxic gas with a pungent odor. The molecule is a pseudohalogen. Cyanogen molecules consist of two CN groups – analogous to diatomic halogen molecules, such as Cl2, but far less oxidizing. The two cyano groups are bonded together at their carbon atoms: N≡C‒ C≡N, although other isomers have been detected. The name is also used for the CN radical, and hence is used for compounds such as cyanogen bromide (NCBr) (but see also ''Cyano radical''.) Cyanogen is the anhydride of oxamide: :H2NC(O)C(O)NH2 → NCCN + 2 H2O although oxamide is manufactured from cyanogen by hydrolysis: :NCCN + 2 H2O → H2NC(O)C(O)NH2 Preparation Cyanogen is typically generated from cyanide compounds. One laboratory method entails thermal decomposition of mercuric cyanide: :2 Hg(CN)2 → (CN)2 + Hg2(CN)2 Alternatively, one can combine solutions of copper(II) salts (such as copper(II) sulfate) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CCN (radical)
CCN may refer to: In science and technology * Cement chemist notation, developed to simplify the formulas used by cement chemists * Cereal cyst nematode, a plant disease * Corn cyst nematode, a plant disease * Cerebrocortical necrosis, a nutritional brain disease of cattle * Cloud condensation nuclei * Content centric networking, approach to computer-networking architecture * Controlled-Controlled Not Gate (also known as a Toffoli gate), a component of a reversible computer * Cyclomatic Complexity Number, a software metric *CYR61, CTGF, NOV, the first three proteins identified that belong to the "CCN" protein family - also see CCN intercellular signaling protein *Critical care nursing Organizations * '' Camino Cristiano Nicaragüense'', a Nicaraguan political party * Caribbean Communications Network Ltd., a unit of ONE Caribbean Media Ltd. based in Trinidad and Tobago * Chebucto Community Net in Halifax, Nova Scotia * City College Norwich, a further education college in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
