203-80-5Relevant articles and documents
Hydrogenation and dehydrogenation reactions of the phenalenyl radical/1H-phenalene system at low temperatures
Schneiker, Anita,Csonka, István Pál,Tarczay, Gy?rgy
, (2020)
Phenalenyl radical was generated in situ in inert matrices by laser UV photolysis of 1H-phenalene, and was identified by recording laser induced fluorescence and IR spectra. Theoretical computations predict that the H atom addition to phenalenyl radical is barrierless, while the H atom abstraction from 1H-phenalene has only a small barrier. Upon annealing the Xe matrix after the photolysis, the radical and the H atom recombine, while H atom abstraction from 1H-phenalene is a possible explanation for additional spectral changes. These results show that the phenalenyl radical/1H-phenalene system can be a very effective catalyst in the formation of interstellar H2.
Spectroscopy of the free phenalenyl radical
Oeconnor, Gerard D.,Troy, Tyler P.,Roberts, Derrick A.,Chalyavi, Nahid,Fueckel, Burkhard,Crossley, Maxwell J.,Nauta, Klaas,Stanton, John F.,Schmidt, Timothy W.
supporting information; experimental part, p. 14554 - 14557 (2011/10/18)
After benzene and naphthalene, the smallest polycyclic aromatic hydrocarbon bearing six-membered rings is the threefold-symmetric phenalenyl radical. Despite the fact that it is so fundamental, its electronic spectroscopy has not been rigorously scrutinized, in spite of growing interest in graphene fragments for molecular electronic applications. Here we used complementary laser spectroscopic techniques to probe the jet-cooled phenalenyl radical in vacuo. Its spectrum reveals the interplay between four electronic states that exhibit Jahn-Teller and pseudo-Jahn-Teller vibronic coupling. The coupling mechanism has been elucidated by the application of various ab initio quantum-chemical techniques.
Complete study of the pyrolysis and gasification of scrap tires in a pilot plant reactor
Conesa, Juan A.,Martin-Gullon,Font,Jauhiainen
, p. 3189 - 3194 (2008/12/21)
The pyrolysis and gasification of tires was investigated in a pilot plant reactor provided with a system for condensation of semivolatile matter. The study comprised experiments at 450°, 750°, and 1000°C both in nitrogen and 10% oxygen atmospheres. In the gas phase, only methane and benzene yields increased with temperature until 1000°C. In the liquids, the main components were styrene, limonene, and isoprene. The solid fraction (including soot) increased with temperature. Zinc content of the char decreased with increasing temperature. Analysis of the surface area of the solids showed that the area was similar in all cases to that of a commercial carbon black. The higher surface of the soot with respect to the chars was observed. The results coincided with published findings, i.e., kinetic severity function values would produce 0.2% of methane at 450°C and 4.5% at 750°-1000°C.
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.
Substituent-induced polarization of charge in phenalenyl anions
Van Dijk, Joost T. M.,Steggerda, Steven A.,Lugtenburg, Johan,Cornelisse, Jan
, p. 86 - 94 (2007/10/03)
The effect of trimethylsilyl, alkynyl and cyano substituents on the charge distribution of the phenalenyl anionic nucleus was examined using semiempirical calculations and NMR spectroscopy. With these techniques it was demonstrated that the trimethylsilyl and cyano substituents are capable of attracting adjacent negative charge. Examples of reactions from the literature confirm the charge-attracting capabilities of the trimethylsilly substituent. The alkynyl substituent was shown to perturb the charge distribution of the phenalenyl moiety to a much lesser degree than the vinyl substituent in the 1-hydropyrenyl anion. Copyright
Resonance energy of diradicals - 1,8-naphthoquinodimethane
Roth, Wolfgang R.,Unger, Christian,Wasser, Thorsten
, p. 2155 - 2169 (2007/10/03)
From the racemization of 19c and the temperature and NO dependence of the trapping rate of 20b between 218 and 288°C the energy profile for the equilibrium 19b ? 20b is derived. The singlet-triplet splitting of the diradical is 2.5 kcal · mol-1 with the triplet being the ground state. By comparison of the experimental reaction enthalpy with the analogous value for 25, 26 or a hypothetical model reaction with non-interacting radicals it is shown that the stabilizing interaction of the radicals in the singlet state of 20b is negligible making the stabilization of the triplet equivalent to the singlet-triplet splitting. By using literature data it is shown by an analogous analysis that the interaction of the radicals in the bisallyl diradical 28 and in the triplet state of the trimethylenmethane derivative 29 is also negligible whereas in the singlet state of 29 the interaction is strongly destabilizing. VCH Verlagsgesellschaft mbH, 1996.
Synthesis of various (pentamethylcyclopentadienyl) Ru(riG-arene) complexes of phenalene derivatives
Meltzheim, Benedicte,Kilway, Kathleen,Lignell, Martin,Waegell, Bernard,Tort, Frederic
, p. 979 - 985 (2007/10/03)
The η6-(pentamethylcyclopentadienyl)ruthenium complexes of phenalenone 9, phenalenes 10 and 11, phenalane 12 and phenalanone 13 have been prepared from the corresponding phenalenic derivatives, following Chaudret's procedure. The electron-donating pentamethylcyclopentadienyl ligand modifies the reactivity of phenalene in the corresponding ruthenium complexes, which become unreactive towards dioxygen. Phenalenone, which reacts readily with 2-methylindole in presence of para-toluenesulfonic acid, becomes unreactive when complexed to ruthenium (complex 9). (. Elsevier,.
Synthesis and photoreactions of some spiro
Hempenius, M. A.,Lugtenburg, J.,Cornelisse, J.
, p. 403 - 409 (2007/10/02)
Reaction of the phenalenyl anion (1-) with 1,2-dibromoethane, 1,4-dibromobutane and 1,5-dibromopentane results in the formation of (bromoalkyl)phenalene derivatives.These derivatives undergo ring closure when treated with base to spirophenalene> (2), spirocyclopentane-1,1'-phenalene> (4) and spiroycyclohexan-1,1'-phenalene> (5).Reaction of 1- with 1,3-dibromopropane gives a 1:1 mixture of 1,2,3,5-tetrahydropyrene (3a) and 1,2,3,6-tetrahydropyrene (3b), both of which can easily be dehydrogenated to pyrene.Photochemical reactions of spiro 2,4 and 5 are discussed.The introduction and photochemical opening of a spirocyclopropane ring in phenalene results in the formation of 1,2-dihydro-4H-cyclopentaphenalene (6), a compound with a fused five-membered ring.The construction of pyrene and cyclopentaphenalene skeletons starting from phenalene represents a new approach in the synthesis of polycyclic aromatic hydrocarbons and their derivatives.
