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Pentadiene
In chemistry, pentadiene is any hydrocarbon with an open chain of five carbons, connected by two single bonds and two double bonds. All those compounds have the same molecular formula . Specifically, it may be * 1,2-pentadiene, or ethyl allene, =C=CH––. * 1,3-pentadiene, =CH–CH=CH- with two isomers: ** ''cis''-1,3-pentadiene. ** ''trans''-1,3-pentadiene, or piperylene. * 1,4-pentadiene, =CH––CH=. * 2,3-pentadiene, –CH=C=CH–, with two enantiomers (''R'' and ''S''). See also * Allene * Pentene * Pentane * Hexadiene * Butadiene * Cyclopentadiene Cyclopentadiene is an organic compound with the chemical formula, formula C5H6.LeRoy H. Scharpen and Victor W. Laurie (1965): "Structure of cyclopentadiene". ''The Journal of Chemical Physics'', volume 43, issue 8, pages 2765-2766. It is often ab ... References James R. Durig, Stephen Bell, Gamil A. Guirgis (1996): "Infrared and Raman spectra, conformational stability, ab initio calculations and vibrational assignment for 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopentadiene
Cyclopentadiene is an organic compound with the chemical formula, formula C5H6.LeRoy H. Scharpen and Victor W. Laurie (1965): "Structure of cyclopentadiene". ''The Journal of Chemical Physics'', volume 43, issue 8, pages 2765-2766. It is often abbreviated CpH because the cyclopentadienyl anion is abbreviated Cp−. This colorless liquid has a strong and unpleasant odor. At room temperature, this cyclic diene dimer (chemistry), dimerizes over the course of hours to give dicyclopentadiene via a Diels–Alder reaction. This dimer can be retro-Diels–Alder reaction, restored by heating to give the monomer. The compound is mainly used for the production of cyclopentene and its derivatives. It is popularly used as a precursor to the cyclopentadienyl anion (Cp−), an important ligand in cyclopentadienyl complexes in organometallic chemistry. Production and reactions Cyclopentadiene production is usually not distinguished from dicyclopentadiene since they interconvert. They ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allene
In organic chemistry, allenes are organic compounds in which one carbon atom has double bonds with each of its two adjacent carbon centres (). Allenes are classified as diene#Classes, cumulated dienes. The parent compound of this class is propadiene, which is itself also called ''allene''. Compounds with an allene-type structure but with more than three carbon atoms are members of a larger class of compounds called cumulenes with bonding. History For many years, allenes were viewed as curiosities but thought to be synthetically useless and difficult to prepare and to work with.The Chemistry of the Allenes (vol. 1−3); Landor, S. R., Ed.; cademic Press: London, 1982. Reportedly, the first synthesis of an allene, glutinic acid, was performed in an attempt to prove the non-existence of this class of compounds. The situation began to change in the 1950s, and more than 300 papers on allenes have been published in 2012 alone. These compounds are not just interesting intermediates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piperylene
Piperylene or 1,3-pentadiene is an organic compound with the formula . It is a volatile, flammable hydrocarbon. It is one of the five positional isomers of pentadiene. Reactions and occurrence Piperylene is a typical diene. It forms a sulfolene upon treatment with sulfur dioxide. Piperylene is the product of the decarboxylation of sorbic acid, a common anti-mold agent. Piperylene is obtained as a byproduct of ethylene production from crude oil, combustion of biomass, waste incineration and exhaust gases. It is used as a monomer in the manufacturing of plastics, adhesives and resins. at Shell Chemicals. Retrieved 2009-05-19. See also * |
Butadiene
1,3-Butadiene () is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two vinyl groups. It is the simplest conjugated diene. Although butadiene breaks down quickly in the atmosphere, it is nevertheless found in ambient air in urban and suburban areas as a consequence of its constant emission from motor vehicles. The name butadiene can also refer to the isomer, 1,2-butadiene, which is a cumulated diene with structure H2C=C=CH−CH3. This allene has no industrial significance. History In 1863, the French chemist E. Caventou isolated butadiene from the pyrolysis of amyl alcohol. This hydrocarbon was identified as butadiene in 1886, after Henry Edward Armstrong isolated it from among the pyrolysis products of petroleum. In 1910, the Russian chemist Sergei Lebedev polymerized butadiene and obtained a material wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentene
Pentenes are alkenes with the chemical formula . Each contains one double bond within its molecular structure. Six different compounds are in this class, differing from each other by whether the carbon atoms are attached linearly or in a branched structure, and whether the double bond has a Cis–trans isomerism, ''cis'' or ''trans'' form. Straight-chain isomers 1-Pentene is an alpha-olefin. Most often, 1-pentene is made as a byproduct of catalytic cracking, catalytic or thermal cracking of petroleum, or during production of ethylene and propylene via thermal cracking of hydrocarbon fractions. The only commercial manufacturer of 1-pentene is Sasol, Sasol Ltd, where it is separated from crude made by the Fischer–Tropsch process. 2-Pentene has two geometric isomers, ''cis''-2-pentene and ''trans''-2-pentene. ''Cis''-2-Pentene is used in olefin metathesis. Branched-chain isomers The branched isomers are 2-methylbut-1-ene, 3-methylbut-1-ene (isopentene), and 2-methylbut-2-ene (is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentane
Pentane is an organic compound with the formula C5H12—that is, an alkane with five carbon atoms. The term may refer to any of three structural isomers, or to a mixture of them: in the IUPAC nomenclature, however, pentane means exclusively the ''n''-pentane isomer; the other two are called isopentane (methylbutane) and neopentane (dimethylpropane). Cyclopentane is not an isomer of pentane because it has only 10 hydrogen atoms where pentane has 12. Pentanes are components of some fuels and are employed as specialty solvents in the laboratory. Their properties are very similar to those of butanes and hexanes. Industrial uses Pentanes are some of the primary blowing agents used in the production of polystyrene foam and other foams. Usually, a mixture of n-, i-, and increasingly cyclopentane is used for this purpose. Acid-catalyzed isomerization gives isopentane, which is used in producing high-octane fuels. Because of their low boiling points, low cost, and relative safety, pen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexadiene
1,5-Hexadiene is the organic compound with the formula (CH)(CH=CH). It is a colorless, volatile liquid. It is used as a crosslinking agent and precursor to a variety of other compounds. Synthesis 1,5-Hexadiene is produced commercially by the ethenolysis of 1,5-cyclooctadiene: :(CHCH=CHCH) + 2 CH=CH → 2 (CH)CH=CH The catalyst is derived from ReO on alumina. A laboratory-scale preparation involves reductive coupling of allyl chloride Allyl chloride is the organic compound with the formula C H2=CHCH2 Cl. This colorless liquid is insoluble in water but soluble in common organic solvents. It is mainly converted to epichlorohydrin, used in the production of plastics. It is a ch ... using magnesium: :2 ClCHCH=CH + Mg → (CH)(CH=CH) + MgCl References Alkadienes Monomers {{Hydrocarbons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
