- NMR and DFT study on onium ions derived from substituted fluoranthenes and benzo[κ]fluoranthenes
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Fluoranthene and benzo[k]fluoranthene (3) are nonalternant polyaromatic hydrocarbons. Their derivatives, 3-acetyl, 8-acetyl, 3-nitro, and 3-aminofluoranthenes (4, 5, 7, and 8) were reacted in FSO3H/SO 2ClF and the solutions were observed by NMR measurements at low temperatures, which showed the formation of PAH-substituted onium ions. The most deshielded 13C peaks in fluoranthene frames were observed at 155.7 and 148.7 ppm for 4H+, 154.4 ppm for 5H+, 159.1 and 139.6 ppm for 7H+, and 139.7 ppm for 8H+. Distribution of the positive charges were estimated on the basis of changes in 13CNMR chemical shifts between onium ions and their corresponding parent compounds. Only limited delocalization of positive charges into the aromatic rings was found to occur. GIAO-derived NMR chemical shifts calculated by the DFT method were generally consistent with the experimental chemical shifts. DFT calculations suggested that benzo[k]fluoranthene (3) is favored to be protonated at C-3/C-7 positions. GIAO-derived NICS(1)zz were computed to elucidate aromaticity/antiaromaticity, and the results suggested that the five-membered rings are antiaromatic for cations 4H+, 7H+, 8H +, and 3aH+ (3-benzo[k]fluoranthenium ion).
- Okazaki, Takao,Adachi, Taisuke,Kitagawa, Toshikazu
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p. 464 - 471
(2013/05/22)
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- Nitration of polycyclic aromatic hydrocarbons using a supported catalyst
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We report the use of a catalyst, sulfuric acid supported on silica-gel, as a promising method for facile, high yielding, regioselective syntheses of mononitrated polycyclic aromatic hydrocarbons, 6-nitrochrysene, 1- nitropyrene, 1-nitronaphthalene, 2-nitrofluorene, 3-nitrofluoranthene, and 9- nitroanthracene.
- Smith, Amy C.,Narvaez, Lorena D.,Akins, Bridget G.,Langford, Moses M.,Gary, Thomas,Geisler, Victoria J.,Khan, Farooq A.
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p. 4187 - 4192
(2007/10/03)
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- Formation of mutagenic nitrofluoranthenes in the gas-solid heterogeneous reaction of particle-associated fluoranthene in NO2-O3-O2 system
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In the gas-solid heterogeneous reactions of particle-supported fluoranthene with ppm levels of nitrogen dioxide and ozone, dinitrofluoranthenes and 3-introfluoranthene (3-NF) were formed only in the dark and 2-NF was formed only under photoirradiation while 1-, 7-, and 8-NFs were formed under both conditions. Yield and distribution of the products varied depending on the kind of supports employed.
- Inazu, Koji,Kobayashi, Takaaki,Hisamatsu, Yoshiharu
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p. 1105 - 1106
(2007/10/03)
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- Synthesis and characterization of nitro-, nitroso-, and aminofluoranthenes
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The synthesis is reported of the five mononitrofluoranthenes. 1-Nitrofluoranthene was synthesized in 20percent from fluoranthene, 2-nitrofluoranthene in 24percent from 1,2,3,10b-tetrahydrofluoranthene, 3-nitrofluoranthene in 13percent from fluoranthene and 7- and 8-nitrofluoranthene in 34percent from 1,2,3,10b-tetrahydrofluoranthene.The pure nitrofluoranthenes were converted into their nitroso and amino analogues.The nitrosopyrenes were also synthesized.Characterisation of each compound is described.
- Haeringen, C. J. van,Aten, N. F.,Cornelisse, J.,Lugtenburg, J.
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p. 335 - 344
(2007/10/02)
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- A dichotomy in the nitration of fluoranthene with NO2/N2O4: Mechanistic and toxicological implications
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The nitration of fluoranthene with nitrogen dioxide can occur by two distinctive reaction pathways. These paths can be distinguished by product analysis, since fluoranthene is a nonalternant hydrocarbon. Free-radical nitration and electrophilic nitration give different products. In solvents with dielectric constants lower than that of CH2Cl2 and in the absence of acid catalysis, the exclusive reaction pathway is homolytic in nature. The products of the homolytic reaction pathway can be interpreted as arising via a multiple-step addition-elimination mechanism and are notable for the formation of 2-nitrofluoranthene (the major product in CCl4 but absent under electrophilic nitration conditions) and the unusually large amounts of the expected 1,2-dinitrofluoranthene and 1,3-dinitrofluoranthene. The ionic reaction pathway is subject to both Lewis and Bronsted acid catalysis, particularly in CH2Cl2, and is inhibited by nonnucleophilic bases like 2, 6-di-tert-butylpyridine. At temperatures lower than 25°C, the ionic reaction pathway predominates, even in CCl4. 2-Nitrofluoranthene is a marker for the free-radical nitration of fluoranthene, and its presence in polluted tropospheric air suggests that free-radical nitration by NO2 may occur under atmospheric conditions.
- Squadrito,Fronczek,Church,Pryor
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p. 2616 - 2621
(2007/10/02)
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- Reaction of Dinitrogen Pentoxide with Fluoranthene
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The products and mechanisms of the reactions of dinitrogen pentoxide (N2O5) with fluoranthene (FL) in aprotic solvents have been investigated.The influence of solvent polarity and temperature and the effects of addition of HNO3 on the resulting nitrofluoranthene (NFL) isomer distributions have been studied.These data compared with the NFL isomer distributions resulting from the reactions of FL with N2O5 and other nitrating agents in the gas and absorbed phases.In the gas phase and in CCl4 solution at ambient temperature, 2-NFL is the only mononitro isomer formed from the reaction of FL with N2O5.However, in more polar solvents (CH3CN and CH3NO2) and in CCl4 at subambient remperature (-15 grad C), as well as with FL in the adsorbed state, reaction with N2O5 produces only the 3-, 8-, 7-, and 1-NFL isomers.A homolyticmechanism for the formation of the 2-NFL isomer is postulated.
- Zielinska, Barbara,Arey, Janet,Atkinson, Roger,Ramdahl, Thomas,Winer, Arthur M.,Pitts, James N. Jr.
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p. 4126 - 4132
(2007/10/02)
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- Separation and Characterization of Mononitro Derivatives of Phenanthrene, Pyrene, Chrysene, Fluoranthene and Triphenylene
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Mononitro derivatives of selected polycyclic aromatic hydrocarbons with 3 and 4 condensed rings have been synthesized to obtain samples for measurements of mutagenic properties.Crude purification of the compounds was carried out on gravity columns prior to final purification by HPLC to a purity of approximately 99.9percent.Structural isomers were identified from NMR, MS and UV spectra.
- Svendsen, Helge,Roenningsen, Hans-Petter,Sydnes, Leiv K.,Greibrokk, Tyge
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p. 833 - 844
(2007/10/02)
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