2471-84-3Relevant articles and documents
A REINVESTIGATION OF THE THERMAL REARRANGEMENTS OF NAPHTHVALENE
Kjell, Douglas P.,Sheridan, Robert S.
, p. 5731 - 5734 (1985)
The previously reported thermal transformation of naphthvalene to benzofulvene has been shown to be a catalyzed process; naphthvalene rearranges to naphthalene under flow pyrolysis conditions.
Die Synthese und der thermische Zerfall des 1,2-Diazabenzosemibullvalens und dessen Beziehung zur Thermolyse des Benzobenzvalens
Burger, Ulrich,Mentha, Yves,Thorel, Pierre Jean
, p. 670 - 675 (1986)
The -photoadduct of naphthalene and 4-phenyl-4H-1,2,4-triazol-3,5-dione (PTAD) was subjected to a triplet-sensitized di-?-methane rearrangement.Hydrolysis of the resulting urazol 15 gave a stable semicarbazide 16 which by nickel-peroxide oxidation gave 1,2-diazabenzosemibullvalene (10).At 40 deg C, the latter decays in CHCl3 solution to produce benzofulvene (2) as the principal product, accompanied by benzobenzvalene (1) and small amounts of naphthalene.This decay reaction is rationalized in terms of a 1,3-dipolar cycloreversion which is followed by denitrogenation to give indenyl carbene (9).The thermolysis of 1 in solution is believed to produceed via the same carbene.At present, these findings provide only a partial answer to the benzobenzvalene enigma (i.e., in solution at 150 deg C, 1 gives 2, but in the gas-phase at 300 deg C, 1 yields naphthalene).MeOH is shown to add readily to 10 in a homologous Michael addition.
Thermal isomerization of azulene. Single-pulse shock tube investigation
Laskin, Alexander,Lifshitz, Assa
, p. 257 - 261 (1996)
The thermal isomerization of azulene was studied behind reflected shocks in a pressurized driver single-pulse shock tube. The temperature range covered was 1050-1400 K at overall densities of ～2.5 × 10-5 mol/cm3. The main reaction of azulene under these conditions is a unimolecular isomerization to naphthalene, but it also isomerizes, although at a much lower rate, to another isomer. The suggested tetracyclic triene intermediate structure for the uzulene-naphthalene isomerization can lead also to transition states that can describe isomerizations to 1-methylene-1H-indene and 1,2,3-metheno-1H-indene,2,3-dihydro. Small quantities of C2H2, C4H2, C6H6, and C6H5-C≡CH were also found in the post-shock samples, particularly at high temperatures. The Arrhenius parameters of the two high pressure limit rate constants for the isomerization processes are: azulene ??? naphthalene, k1 = 1012.93 exp(-62.8 × 103/RT) s-1 azulene → second isomer, k2 = 1012.42 exp(-69.5 × 103/RT) s-1 A discussion of the mechanism for these isomerization processes is presented. * Author to whom correspondence should be addressed.
Aromatic hydrocarbon growth from indene
Lu, Mingming,Mulholland, James A.
, p. 625 - 633 (2007/10/03)
Aromatic hydrocarbon growth from indene (C9H8), which contains the five-membered ring cyclopentadienyl moiety, was investigated experimentally in a 4 s flow reactor over a temperature range 650-850°C. Major products observed were three C18H12 isomers (chrysene, benz[a]anthracene and benzo[c]phenanthrene), two C17H12 isomers (benzo[a]fluorene and benzo[b]fluorene), and two C10H8 isomers (naphthalene and benzofulvene). Reaction pathways to these products are proposed. Indenyl radical addition to indene produces a resonance-stabilized radical intermediate which further reacts by one of two routes. Rearrangement by intramolecular addition produces a bridged structure that leads to the formation of C17H12 and C10H8 products. Alternatively, β scission produces biindenyl, which leads to the formation of C18H12 products by a ring condensation mechanism analogous to that proposed for cyclopentadiene-to-naphthalene conversion. Temperature dependencies of both the partitioning between these two routes and the product isomer distributions are consistent with thermochemical modeling using semi-empirical molecular orbital methods. The results further illustrate the role of resonance-stabilized radical rearrangement in aromatic growth and condensation of systems with cyclopentadienyl moieties.
Evolution of products in the combustion of scrap tires in a horizontal, laboratory scale reactor
Fullana,Font,Conesa,Blasco
, p. 2092 - 2099 (2007/10/03)
A horizontal laboratory reactor was used to study the evolution of byproducts from the combustion of scrap tires at five nominal temperatures (ranging from 650 to 1050 °C) and different oxygen:sample ratios A model was used to calculate the bulk air ratio (λ), and the oxygen consumption was discussed considering this ratio λ. More than 100 volatile and semivolatile compounds were identified and quantified by gas chromatography mass spectrometry, plotting their yields vs the bulk air ratio and temperature. Five different behaviors considering the bulk air ratio and the temperature were identified.
Characterization of the combustion products of polyethylene
Piao, Mingjun,Chu, Shaogang,Zheng, Minghui,Xu, Xiaobai
, p. 1497 - 1512 (2007/10/03)
Polyethylene (PE) was burned in a tube-type furnace with an air flow at a temperature of 600~900°C. Combustion products were collected with glass wool, glass fiber filter, and XAD-2 adsorbent. The analysis of the products was performed with GC-FID and GC-MSD. At low temperature, hydrocarbons were the major components, while at higher temperature the products were composed of polycyclic aromatic hydrocarbons. With the high performance of the Hewlett-Packard 6890GC-5973MSD, more compounds were identified in comparison with previous studies.
Pyrolytic cyclisation reactions of 3-azolylpropenyl alcohols; unexpectedly facile thermal decomposition of 5H-pyrrolo-[2,1-a]isoindole
Clark, Bernard A. J.,Despinoy, Xavier L. M.,McNab, Hamish,Sommerville, Craig C.,Stevenson, Elizabeth
, p. 2049 - 2051 (2007/10/03)
Flash vacuum pyrolysis (FVP) of 3-azolylpropenyl alcohols 5-7, 12 or 15 at 650-700°C (10-2-10-3 Torr) causes loss of water and cyclisation to give 3H-pyrrolizine 8 and its analogues 9, 10, 13 and 16; at higher temperatures (e.g. 900°C) 5H-pyrrolo[2,1-a]isoindole 13 decomposes by loss of HCN to give naphthalene 18 and benzofulvene 19 and the mechanism of this transformation is studied by deuterium labelling.
Benzocyclohex-1-en-3-yne at high temperature
Lu, Peter J.,Pan, Weitao,Jones Jr., Maitland
, p. 8315 - 8318 (2007/10/03)
Generation of benzocyclohex-1-en-3-yne in two ways leads to naphthalene and methyleneindene (benzofulvene). Labeling studies favor a multistep mechanism involving an initial electrocyclic ring opening, and carbene- alkene interconversions.
Addition and Cyclization Reactions in the Thermal Conversion of Hydrocarbons with Enyne Structure, I. Detailed Analysis of the Reaction Products of Ethynylbenzene
Hofmann, Joerg,Zimmermann, Gerhard,Guthier, Klaus,Hebgen, Peter,Homann, Klaus-Heinrich
, p. 631 - 636 (2007/10/02)
The pyrolysis of ethynylbenzene (C8H6, 1) was studied in a flow system between 700 and 1100 deg C (reaction time about 0.3 s) by using a mixture of 5 mol-percent of 1 in nitrogen and also in hydrogen at 700 deg C.The products were analyzed gas chromatogra
