590-19-2Relevant articles and documents
The 213.8-nm Photochemistry of Gaseous 1,3-Butadiene and the Structure of Some C3H3 Radicals
Collin, Guy J.,Deslauriers, Helene,Mare, George R. de,Poirier, Raymond A.
, p. 134 - 141 (1990)
A systematic study of the 213.8-nm (zinc line ) photochemistry of 1,3-butadiene has been made either in the absence or in the presence of various additives - such as radical scavengers (O2,NO,DI) and collisional quenchers - in the gas phase (pressure between 1 and 500 Torr).The major fate of the photoexcited 1,3-butadiene molecule is isomerization to the 1,2-butadiene structure which may then decompose to methyl and C3H3 radicals (Φ = 0.64 +/- 0.04 at 1 Torr of 1,3-butadiene).Minor processes include decomposition to the acetylene + ethylene couple (Φ = 0.22 +/- 0.02) or to vinylacetylene (Φ = 0.038 +/- 0.003) and molecular hydrogen.These two minor processes occur from different excited states.Some 2-butyne (Φ / = 10, the highest ratio used, Φ(allene + propyne)/ Φ(CH3D) = 0.72 and a fraction of the C3H3 radicals are still not accounted for (reaction with 1,3-butadiene and/or recombination ?).The relative energies obtained by ab initio RHF-SCF geometry optimizations for the doublet electronic state of the C3H3 radical structures are E(propargyl) 2B1 state) is the lowest energy one.There are probably at least two distinct C3H3 radical structures (different states) present in the far-UV photolysis of 1,3-butadiene.
An acelylenically of a diene compound and/or method of manufacturing
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Paragraph 0427; 0428; 0437-0445, (2017/03/28)
Provided is a novel method for producing a compound having acetylene bonds and/or a diene. The method for producing a compound having acetylene bonds and/or a diene is characterized in that at least one selected from the group consisting of ketone compound (I), ketone compound (II), aldehyde compound (III), aldehyde compound (IV), and aldehyde compound (V) is dehydrated in the presence of a catalyst wherein a carrier containing silica supports at least one selected from the group consisting of compounds containing group 1 metal elements, compounds containing group 2 metal elements, group 1 metal elements, and group 2 metal elements.
Metal ions do not play a direct role in the formation of carbon-carbon triple bonds during reduction of trihaloalkyls by CrII or V II
Levy, Ophir,Bino, Avi
supporting information, p. 15944 - 15947 (2013/02/23)
Carbyne radicals: Reactions of trihaloalkyl compounds with Cr2+ or V2+ in aqueous solutions yield alkynes and other products. Stepwise halogen abstractions from the trihaloalkyls form alkyl carbyne triradicals in solution. These radicals undergo coupling reactions, producing triply bonded alkyne molecules (see scheme). This process is not metal-assisted and does not occur in the coordination sphere of the metal ions.
Rate constants and the H atom branching ratio of the reactions of the methylidyne CH(X2Π) radical with C2H2, C2H4, C3H4 (methylacetylene and allene), C3H6 (
Loison, Jean-Christophe,Bergeat, Astrid
body text, p. 655 - 664 (2009/05/07)
The reactions of the CH radical with several unsaturated hydrocarbons C2H2 (acetylene), C2H4 (ethylene), C3H4 (methyl-acetylene and allene), C3H 6 (propene) and C
Nucleophilic reactivity of 1-zirconacyclopent-3-ynes: Carbon-carbon bond formation with aldehydes
Suzuki, Noriyuki,Watanabe, Takaaki,Hirose, Takuji,Chihara, Teiji
, p. 5317 - 5321 (2008/03/12)
Nucleophilic reactions of 1,1-bis(η5-cyclopentadienyl)-1-zirconacyclopent-3-yne (1) with proton and aldehydes were studied. The reaction with HCl gave a mixture of 2-butyne and 1,2-butadiene. Complex 1 reacted with benzaldehyde to give 1-phenyl-2-methyl-2,3-butadien-1-ol (3) in moderate yields in the presence of a proton source such as triethylammonium hydrochloride, while it gave 2-methylene-1-phenyl-3-buten-1-ol (4) on using triethylammonium tetraphenylborate.
Solvent extraction
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Page/Page column 4-6, (2008/06/13)
In a method for the solvent extraction of butadiene from a mixture of hydrocarbons having four carbon atoms per molecule, which method inherently produces tars, the extraction process is operated with a tar loading level, relative to the solvent employed, of no more than about 1.6 wt. %.
Kinetics and products of propargyl (C3H3) radical self-reactions and propargyl-methyl cross-combination reactions
Fahr, Askar,Nayak, Akshaya
, p. 118 - 124 (2007/10/03)
Propargyl and methyl radicals were produced through the 193-nm excimer laser photolysis of mixtures of C3H3Cl/He and CH3N2CH3/He, respectively. Gas chromatographic and mass spectrometric (GC/MS) product analyses were employed to characterize and quantify the major reaction products. The rate constants for propargyl radical self-reactions and propargyl-methyl cross-combination reactions were determined through kinetic modeling and comparative rate determination methods. The major products of the propargyl radical combination reaction, at room temperature and total pressure of about 6.7 kPa (50 Torr) consisted of three C6H6 isomers. The rate constant determination in the propargyl-methyl mixed radical system yielded a value of (4.0±0.4)×10-11 cm3 molecule-1 s-1 for propargyl radical combination reactions and a rate constant of (1.5±0.3)×10-10 cm3 molecule-1 s-1 for propargyl-methyl cross-combination reactions. The products of the methyl-propargyl cross-combination reactions were two isomers of C4H6, 1-butyne (about 60%) and 1,2-butadiene (about 40%).
UV laser-induced photolysis of silacyclopent-3-ene: Unseparable photochemistry of reactant and product for chemical vapour deposition of Si/C/H polymer
Pola, Josef,Ouchi, Akihiko,Urbanova, Marketa,Koga, Yoshinori,Bastl, Zdenek,Subrt, Jan
, p. 246 - 250 (2007/10/03)
UV laser-induced photolysis of silacyclopent-3-ene in the gas phase is a clean extrusion of silylene yielding buta-1,3-diene. Silylene self-polymerisation and consequent deposition of SinH2n agglomerates is precluded by concurrently occurring photolysis of buta-1,3-diene. The solid polymeric deposit being produced through polymerisation steps involving both H2Si: and the products of the buta-1,3-diene photolysis makes the reaction suitable for chemical vapour deposition of Si/C/H films.
Use of but-1-yne as a probe for the characterization of the basicity of alkali-exchanged zeolites
Lavalley, Jean-Claude,Lamotte, Jean,Travert, Arnaud,Czyzniewska, Jolanta,Ziolek, Maria
, p. 331 - 335 (2007/10/03)
But-1-yne has been adsorbed at room temperature on a series of LiNa, Na and CsNaX and Y zeolites and also on CsNaX,9Cs and CsNaY,9Cs samples containing nine Cs atoms occluded by a unit cell. An IR study of the 3000-2800 cm-1 frequency range clearly showed that but-1-yne isomerized into but-2-yne on CsNaX,9Cs whereas the observation of a band near 1950 cm-1 in the case of CsNaY,9Cs characterized the formation of buta-1,2-diene. Such partial transformation of but-1-yne to isomers did not occur on LiNa and Na samples, allowing one to study the basicity of such zeolites from the v(≡CH) shift which decreases in the following order: NaX > LiNaX > NaY > LiNaY. The main feature is the observation of at least two perturbed v(≡CH) bands for the NaX and NaY samples, revealing the heterogeneity of the basic sites. This result is discussed taking into account the presence of cations in different positions.
Homolytic Bond Dissociation Enthalpies of the C-H Bonds Adjacent to Radical Centers
Zhang, Xian-Man
, p. 1872 - 1877 (2007/10/03)
Homolytic bond dissociation enthalpies (BDEs) at 0 and 298 K of the C-H bonds adjacent to various radical centers have been obtained from ab initio CBS-4 (complete basis set) model calculations and experimental data available in the literature. The BDEs of the G-H bonds adjacent to the radical centers derived from 11 saturated hydrocarbons were found to be 33.5 ±3 kcal/mol at 298 K. The BDEs of the C-H bonds adjacent to nine allylic and benzylic radical centers were found to be 48 ±3 kcal/mol at 298 K, but the benzylic C-H BDE of the PhCH2CH2 radical was found to be only 29.7 and 30.5 kcal/mol at 0 and 298 K, respectively. The BDEs of the vinylic C-H bonds adjacent to four vinylic radical centers were found to be 35.5 ±3.5 kcal/mol at 298 K. The BDEs of the vinylic C-H bonds adjacent to three allylic radical centers were found to be 56.5 ±3 kcal/ mol at 298 K. These results suggest that the radical centers weaken the adjacent C-H bond strengths by about 50-70 kcal/mol. The calculated BDEs agree within ±2 kcal/mol with most of the available experimental results. Isomerization enthalpies of butenes and pentenes have been obtained. Substituent effects on BDEs have also been examined.
