- Electrophilic Substitution of 3,4-Dihydrocyclopentapyrene and the 3-Ketone
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Bromination of 3,4-dihydrocyclopentapyrene (1) with bromine yielded predominantly the corresponding 8-bromide; on the other hand, a similar reaction of cyclopentapyren-3(4H)-one (2) afforded the 4-bromide.The Friedel-Crafts acetylation of 1 and 2 with acetyl chloride in the presence of aluminum chloride occurred at sites 8, 6, and 1.The isomeric distribution in the acetylation of 1 was similar to that of 2.The relative reactivity of 2 with 1-acetylpyrene in acetylation was 0.75.The partial rate factor of site 1 of 1 was less than that of the corresponding position of 1-acetylpyrene, in spite of the fact that sites 6 and 8 of 1 were more reactive than the corresponding positions of 1-acetylpyrene.Nitration of 2 using acetyl nitrate in acetic anhydride took place at positions similar to the case of the acetylation of 2; however, the nitration of 1 gave the 5-nitro derivative in addition to the 8, 6 and 1-isomers.
- Minabe, Masahiro,Nishimura, Ryuuji,Kimura, Takao,Tsubota, Motohiro
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- Synthesis of end-cap precursor molecules for (6, 6) armchair and (9, 0) zig-zag single-walled carbon nanotubes
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We report the synthesis and purification of a C60H30 precursor molecule for the end-cap of a (6, 6) armchair and of a C54H24 precursor molecule for a (9, 0) zig-zag type single-walled nanotube. An approach to controlled growth of single-walled carbon nanotubes is suggested.
- Mueller, Andreas,Amsharov, Konstantin Yu.,Jansen, Martin
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supporting information; experimental part
p. 3221 - 3225
(2010/08/07)
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- Quantitative Synthesis and Formation of Cyclopentapyrene 3,4-Oxide under Simulated Atmospheric Conditions
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Cyclopentapyrene 3,4-oxide (2) has been synthesized in a one-step, quantitative reaction using dimethyldioxirane. The oxide, or its thermal rearrangement products cyclopentapyren-3(4H)-one and cyclopentapyren-4(3H)-one, is formed from cyclopentapyrene (1) under simulated environmental conditions. In one case these products are formed when 1 is adsorbed on model particulates and then exposed to the reaction products of tetramethylethylene and ozone in the gas phase.
- Murray, Robert W.,Singh, Megh
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p. 239 - 243
(2007/10/03)
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- Synthesis, purification and spectral analysis of mononitrocyclopentapyrenes
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The synthesis ,purification and characterization of seven isomeric nitrocyclopentapyrenes (nitroCPPs) are described.Nitration of partially hydrogenated CPPs affords mixtures of nitroderivatives, which, after separation, are aromatized with DDQ.The resulting nitroCPPS are characterized by their 1H NMR, 13C NMR, UV-vis, IR and mass spectra.The interaction between the nitro group and the aromatic system of CPP is discussed.
- Braken-van Leersum, A. M. van den,Spijker, N. M.,Lugtenburg, J.,Cornelisse, J.
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p. 628 - 640
(2007/10/02)
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- SYNTHESIS OF 4-NITROCYCLOPENTAPYRENE
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Nitration of cyclopentapyrene in the presence of silver nitrate, sodium nitrite and iodine in acetonitrile yields 4-nitrocyclopentapyrene.
- Braken - van Leersum, A. M. van den,Cornelisse, J.,Lugtenburg, J.
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p. 4823 - 4824
(2007/10/02)
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- Convenient synthesis of cyclopentapyrene and 3,4-dihydrocyclopentapyrene. The reactivity of the pyrene dianion
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The reactivity of the pyrene dianion has been investigated.Initial attack by electrophiles on the pyrene dianion has been shown to take place exclusively at the 4(9)-position, leading to monoanions (11,15) which can be converted into 9-substituted 1,9-dihydropyrene derivatives (12,16).The latter can be rearranged to give the novel 4-substituted 4,5-dihydropyrene derivatives (13,17), which provide access to 4-substituted pyrene derivatives (14,5).Cyclopentapyrene (1) and 3,4-dihydrocyclopentapyrene (2), two widespread environmental contaminants, have been synthesizedfrom pyrene in four (64percent) and in five (62percent), respectiveliy, utilizing the chemical properties of the pyrene dianion.In these easy and straightforward syntheses the thus far unknown 4,5-dihydro-4-pyreneacetic acid (17) plays a major role.
- Tintel, C.,Cornelisse, J.,Lugtenburg, J.
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- Synthesis of Cyclopentapyrene via a High Yield One-step Preparation of Pyren-4-ylacetic Acid from Pyrene
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In a single step and in 95percent yield pyrene can be converted into pyren-4-ylacetic acid from which subsequently cyclopentapyrene (CPP) can be obtained in an overall yield of 60percent.
- Tintel, Kees,Lugtenburg, Johan,Cornelisse, Jan
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p. 185 - 186
(2007/10/02)
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