- Synthesis of 4H-Cyclopentaphenanthrene from Fluorene Skeleton
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4-Fluoreneacetic acid was prepared and its chloride was cyclized with AlCl3 to give 4H-cyclopentaphenanthren-8-ol accompanied by the 8,9-dione.These were both reduced to 4H-cyclopentaphenanthrene: the overall yield was 40-50percent from diphenic acid.The phenol was converted to acetoxy and amino substrates.
- Yoshida, Masaaki,Minabe, Masahiro,Suzuki, Kazuo
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- A Facile Synthesis of 4H-Cyclopentaphenanthrene
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A facile and cheap method for synthesis of 4H-cyclopentaphenanthrene was achieved from fluorene as the starting material via di-t-butylfluorene.
- Minabe, Masahiro,Yoshida, Masaaki,Takayanagi, Tokuei
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- Flash Vacuum Pyrolysis of 5-Diazodibenzocycloheptene. Some Insights into Aromatic Carbene-Arylcarbene Rearrangement
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Flash vacuum pyrolysis of the title diazo compound gives 4H-cyclopentaphenanthrene, which is interpreted as indicating that dibenzocycloheptatrienylidene (13) undergoes the carbene-carbene rearrangement to generate 4-phenanthrylcarbene.The reactivities of 13 are compared with those of other benzoannulated cycloheptatrienylidenes and discussed in terms of the effect of the benzo ring to the activation energy for the rearrangement.
- Tomioka, Hideo,Kobayashi, Noriyuki
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- A Three-Step Synthesis of 4H-Cyclopenta[def]phenanthrene from Pyrene
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4H-Cyclopenta[def]phenanthrene (CPP) is a valuable building block in the production of photoactive polymers, which find use in a wide range of organic electronic applications. Of particular importance is their use in the development of blue-colored, organic light-emitting diodes (OLEDs), which remains a challenge in the field. Unfortunately, commercial sources and synthetic procedures known in the literature are unable to provide enough CPP for large scale implementation. Herein, we report on the development of a novel, gram-scale synthesis of CPP in three steps, starting from pyrene. The key steps in our methodology are the ring contraction of pyrene-4,5-dione to oxoCPP in a single step, as well as the direct reduction of oxoCPP to CPP. Apart from the small number of synthetic steps, our methodology benefits from the use of relatively non-hazardous reagents, together with optimized purification procedures, making CPP accessible in useful quantities.
- Filippov, Dmitri V.,Overkleeft, Hermen S.,Schneider, Grégory F.,van der Ham, Alex
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- Synthesis of 4H-cyclopenta[def]phenanthrene from 1-naphthylacetic acid
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4H-cyclopenta[def ]phenanthrene (CPP) was prepared from 1-naphthylacetic acid in six steps with an overall yield of 36%. From easily available ethyl 1-naphthaleneacetate, the Michael addition and Lewis acid catalyzed dicyclization provided the diketone, which was reduced and dehydrated to give CPP. Copyright
- Kim, Jinwoo,Jin, Youngeup,Song, Suhee,Kim, Il,Suh, Hongsuk
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- Condensed compound and organic light emitting diode comprising the same
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Provided are a condensed cyclic compound represented by chemical formula 1 and an organic electroluminescent device comprising the same. In the chemical formula 1, X, and R1 to R10 refer to the detailed description of the present invention. An organic light emitting device having an organic layer comprising the condensed cyclic compound has properties of low driving voltage, high light emitting efficiency and long lifespan.COPYRIGHT KIPO 2016
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- DEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBONS TO RENDER THEM AVAILABLE FOR BIODEGRADATION
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A method for the degradation of polycyclic aromatic compounds is disclosed that involves dissolving ozone in a bipolar solvent comprising a non-polar solvent in which is of sufficiently non-polar character to solubilized the polycyclic aromatic compounds, and a polar-water-compatible solvent which is fully miscible with the non-polar solvent to form a single phase with the non-polar solvent. The bipolar solvent with dissolved ozone is contacted with the polycyclic aromatic compounds to solubilize the polycyclic aromatic compounds and react the dissolved polycyclic aromatic compounds with the ozone to degrade the dissolved polycyclic aromatic compounds to oxygenated intermediates. The bipolar solvent is then mixed with sufficient water to form separate non-polar and polar phases, the non-polar phase comprising the non-polar solvent and the polar phase comprising the non-polar solvent and the oxygenated intermediates. The polar phase is then diluted and incubated with bacteria to biodegrade the oxygenated intermediates.
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Page/Page column 5-8; 15-16
(2008/12/07)
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- Emission factors and importance of PCDD/Fs, PCBs, PCNs, PAHs and PM 10 from the domestic burning of coal and wood in the U.K.
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This paper presents emission factors (EFs) derived for a range of persistent organic pollutants (POPs) when coal and wood were subject to controlled burning experiments, designed to simulate domestic burning for space heating. A wide range of POPs were emitted, with emissions from coal being higher than those from wood. Highest EFs were obtained for particulate matter, PM10, (～ 10 g/kg fuel) and polycyclic aromatic hydrocarbons (～ 100 mg/ kg fuel for ΣPAHs). For chlorinated compounds, EFs were highest for polychlorinated biphenyls (PCBs), with polychlorinated naphthalenes (PCNs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) being less abundant. EFs were on the order of 1000 ng/kg fuel for ΣPCBs, 100s ng/ kg fuel for ΣPCNs and 100 ng/kg fuel for ΣPCDD/Fs. The study confirmed that mono- to trichlorinated dibenzofurans, Cl1,2,3DFs, were strong indicators of low temperature combustion processes, such as the domestic burning of coal and wood. It is concluded that numerous PCB and PCN congeners are routinely formed during the combustion of solid fuels. However, their combined emissions from the domestic burning of coal and wood would contribute only a few percent to annual U.K. emission estimates. Emissions of PAHs and PM 10 were major contributors to U.K. national emission inventories. Major emissions were found from the domestic burning for Cl1,2,3DFs, while the contribution of PCDD/F-ΣTEQ to total U.K. emissions was minor.
- Lee, Robert G. M.,Coleman, Peter,Jones, Joanne L.,Jones, Kevin C.,Lohmann, Rainer
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p. 1436 - 1447
(2007/10/03)
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- Semivolatile and volatile compounds in combustion of polyethylene
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The evolution of semivolatile and volatile compounds in the combustion of polyethylene (PE) was studied at different operating conditions in a horizontal quartz reactor. Four combustion runs at 500 and 850°C with two different sample mass/air flow ratios and two pyrolytic runs at the same temperatures were carried out. Thermal behavior of different compounds was analyzed and the data obtained were compared with those of literature. It was observed that α,ω-olefins, α-olefins and n-paraffins were formed from the pyrolytic decomposition at low temperatures. On the other hand, oxygenated compounds such as aldehydes were also formed in the presence of oxygen. High yields were obtained of carbon oxides and light hydrocarbons, too. At high temperatures, the formation of polycyclic aromatic hydrocarbons (PAHs) took place. These compounds are harmful and their presence in the combustion processes is related with the evolution of pyrolytic puffs inside the combustion chamber with a poor mixture of semivolatile compounds evolved with oxygen. Altogether, the yields of more than 200 compounds were determined. The collection of the semivolatile compounds was carried out with XAD-2 adsorbent and were analyzed by GC-MS, whereas volatile compounds and gases were collected in a Tedlar bag and analyzed by GC with thermal conductivity and flame ionization detectors.
- Font, Rafael,Aracil, Ignacio,Fullana, Andrés,Conesa, Juan A.
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p. 615 - 627
(2007/10/03)
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- Semi-volatile and particulate emissions from the combustion of alternative diesel fuels
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Motor vehicle emissions are a major anthropogenic source of air pollution and contribute to the deterioration of urban air quality. In this paper, we report results of a laboratory investigation of particle formation from four different alternative diesel fuels, namely, compressed natural gas (CNG), dimethyl ether (DME), biodiesel, and diesel, under fuelrich conditions in the temperature range of 800-1200°C at pressures of approximately 24 atm. A single pulse shock tube was used to simulate compression ignition (CI) combustion conditions. Gaseous fuels (CNG and DME) were exposed premixed in air while liquid fuels (diesel and biodiesel) were injected using a high-pressure liquid injector. The results of surface analysis using a scanning electron microscope showed that the particles formed from combustion of all four of the above-mentioned fuels had a mean diameter less than 0.1 μm. From results of gravimetric analysis and fuel injection size it was found that under the test conditions described above the relative particulate yields from CNG, DME, biodiesel, and diesel were 0.30%, 0.026%, 0.52%, and 0.51%, respectively. Chemical analysis of particles showed that DME combustion particles had the highest soluble organic fraction (SOF) at 71%, followed by biodiesel (66%), CNG (38%) and diesel (20%). This illustrates that in case of both gaseous and liquid fuels, oxygenated fuels have a higher SOF than non-oxygenated fuels. Motor vehicle emissions are a major anthropogenic source of air pollution and contribute to the deterioration of urban air quality. In this paper, we report results of a laboratory investigation of particle formation from four different alternative diesel fuels, namely, compressed natural gas (CNG), dimethyl ether (DME), biodiesel, and diesel, under fuelrich conditions in the temperature range of 800-1200°C at pressures of approximately 24 atm. A single pulse shock tube was used to simulate compression ignition (CI) combustion conditions. Gaseous fuels (CNG and DME) were exposed premixed in air while liquid fuels (diesel and biodiesel) were injected using a high-pressure liquid injector. The results of surface analysis using a scanning electron microscope showed that the particles formed from combustion of all four of the above-mentioned fuels had a mean diameter less than 0.1 μm. From results of gravimetric analysis and fuel injection size it was found that under the test conditions described above the relative particulate yields from CNG, DME, biodiesel, and diesel were 0.30%, 0.026%, 0.52%, and 0.51%, respectively. Chemical analysis of particles showed that DME combustion particles had the highest soluble organic fraction (SOF) at 71%, followed by biodiesel (66%), CNG (38%) and diesel (20%). This illustrates that in case of both gaseous and liquid fuels, oxygenated fuels have a higher SOF than non-oxygenated fuels.
- Sidhu, Sukh,Graham, John,Striebich, Richard
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p. 681 - 690
(2007/10/03)
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- Temperature dependence of DCDD/F isomer distributions from chlorophenol precursors
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The temperature dependence of the gas-phase, rate-limited formation of dichlorodibenzo-p-dioxin (DCDD) and dichlorodibenzofuran (DCDF) isomers from 2,6-dichlorophenol and 3-chlorophenol, respectively, has been studied experimentally in an isothermal flow reactor over the range 300-900°C under pyrolytic, oxidative and catalytic conditions and computationally using semi-empirical molecular orbital methods. At high temperatures, distributions of sets of DCDD/F condensation products are consistent with the calculated thermodynamic distributions, indicating that the relative rates of formation are governed by differences in symmetry and steric hindrance present in the isomer product structures. At low temperatures, however, this is not the case. In the case of 1,6- and 1,9-DCDD formed from 2, 6-dichlorophenol via Smiles rearrangement, the 1,6 isomer is favored at low temperatures more than thermodynamically predicted. This result appears to be consistent with kinetic effects of either the expansion of the five-membered ring Smiles intermediate or a lower activation energy six-membered ring intermediate pathway that produces only the 1,6 isomer. For formation of 1,7-, 3,7- and 1,9-DCDF from 3-chlorophenol, the 1,7 isomer fraction increases at low temperatures whereas thermodynamics predicts a decrease. This result can be attributed to steric effects in alternative sandwich-type approach geometries of phenoxy radicals to form the o, o′-dihydroxybiphenyl (DOHB) intermediate via its keto-tautomers. Higher level molecular theory (ab initio) is needed to provide a more quantitative description of these kinetics.
- Mulholland, James A.,Akki, Umesh,Yang, Yun,Ryu, Jae-Yong
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p. 719 - 727
(2007/10/03)
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- Evolution of products in the combustion of scrap tires in a horizontal, laboratory scale reactor
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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.
- Fullana,Font,Conesa,Blasco
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p. 2092 - 2099
(2007/10/03)
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- Synthesis of peri-cyclobutarenes by thermolysis of [methoxy(trimethylsilyl)methyl]arenes
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[Methoxy(trimethylsilyl)methyl]arenes are readily prepared by reactions of chlorotrimethylsilane with (α-methoxy)arenylmethyllithium reagents as obtained from (methoxymethyl)arenes and t-BuLi. The [methoxy(trimethylsilyl)methyl]arenes eliminate methoxytrimethylsilane at 525-675 °C/0.05-0.10 mm to yield peri-cyclobutarenes as derived from arenylcarbenes. Of importance is the fact that the initial arenylcarbenes generated insert into adjacent peri C-H bonds and/or isomerize to other arenylcarbenes that insert into their peri C-H bonds to give peri- cyclobutarenes. Thus, flash-vacuum pyrolysis of 1- [methoxy(trimethylsilyl)methyl]naphthalene (13) at 575-675 °C/0.05-0.10 mm yields 1H-cyclobuta[de]naphthalene (6, up to 39%) in practical quantities. 2- [Methoxy(trimethylsilyl)methyl]naphthalene (23) also affords 6 as a major thermolysis product. At 510 °C/0.05-0.10 mm 4-methoxy-1- [methoxy(trimethylsilyl)methyl]naphthalene (29) decomposes to 4-methoxy-1H- cyclobuta[de]naphthalene (31, 46%). Under similar conditions, 2-methoxy-1- [methoxy(trimethylsilyl)methyl]naphthalene (33) converts to 1,2- dihydronaphtho[2,1-b]furan (35, 64%) and naphtho[2,1-b]furan (36, 31%), presumably by insertion of 2-methoxy-1-naphthylcarbene (34) into a C-H bond of its o-methoxy group and then dehydrogenation of the resultant dihydrofuran. Further, 1-[methoxy(trimethylsilyl)methyl]-6-methylnaphthalene (39) pyrolyzes (510 °C/0.10-0.20 mm) to 6-methyl-1-naphthylcarbene (40), which isomerizes in part to 7-methyl-1-naphthylcarbene (49); carbenes 40 and 49 then undergo peri C-H insertion to give 3-methyl-1H- cyclobuta[de]naphthalene (41) and 2-methyl-1H-cyclobuta[de]naphthalene (42) in an 8:1 ratio and a combined yield of 44%. The pyrolytic method is particularly valuable for preparing higher peri single carbon atom bridged arenes such as 4H-cyclobuta[jk]phenanthrene (53, 65%) and 3H- cyclobuta[cd]pyrene (59, 86%).
- Engler, Thomas A.,Shechter, Harold
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p. 4247 - 4254
(2007/10/03)
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- Characterization of the combustion products of polyethylene
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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.
- Piao, Mingjun,Chu, Shaogang,Zheng, Minghui,Xu, Xiaobai
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p. 1497 - 1512
(2007/10/03)
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- Equilibrium acidities of some sulfones and sulfoxides in tetrahydrofuran
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Ion pair acidities are reported in tetrahydrofuran (THF) solution for the lithium and cesium salts of several sulfones and one sulfoxide. These salts are shown to be monomeric in the THF solutions studied. Thermodynamic constants are reported for several salts. The results and some conductivity studies show that both the lithium and cesium salts are contact ion pairs in THF. Because of ion association the relative pKs are slightly lower for cesium salts and much lower for lithium salts than for the free ions in DMSO solution.
- Streitwieser, Andrew,Wang, George Peng,Bors, Daniel A.
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p. 10103 - 10112
(2007/10/03)
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- Thermal ring enlargement of aromatic cyclopentadienylidene iminyl radicals. Intramolecular radical addition to the N atom of nitriles results in high yields of aza-aromatics
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It has been demonstrated that ketiminyl radicals, formed at high temperatures (1000 °C, 0.3 s) in oxygen-free nitrogen from phenylhydrazones of benz-anellated cyclopentadienones (fluorenone (9a), methanophenanthrenone (9b)), yield into phenanthridine (8a) and benzo[lmn]-phenanthridine (8b) in yields > 60%. The results point to a predominant addition of intermediately generated phenyl type radicals 5 to the N atom of the nitrile groups followed by bimolecular H-abstraction of the cyclic imidoyl radicals to 8.
- Hofmann, Joerg,Schulz, Kathrin,Zimmermann, Gerhard
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p. 2399 - 2402
(2007/10/03)
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- Synthesis and Hydropyrolysis of Bis-trimethylsilyl Substituted 3-(4H-Cyclopentaphenanthrylidene)-1,4-pentadiyne. A New Route to Corannulene
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3-(4H-Cyclopentaphenanthrylidene)-1,5-bis-(trimethylsilyl)-1,4-pentadiyne (3) was synthesized and converted by hydropyrolysis into corannulene (1) besides others in reasonable yields.It represents a new route of the simplest bowl-shaped polycyclic aromatic hydrocarbon starting from an easily accessible precursor.
- Zimmermann, Gerhard,Nuechter, Uta,Hagen, Stefan,Nuechter, Matthias
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p. 4747 - 4750
(2007/10/02)
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- Carbon Acidity. 72. Ion Pair Acidities of Phenyl Alkyl Ketones. Aggregation Effects in Ion Pair Acidities
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Equilibrium cesium ion pair acidities of acetophenone, propiophenone, isobutyrophenone, and o-methoxyacetophenone and the lithium ion pair acidity of o-methoxyacetophenone in tetrahydrofuran have been determined by an indicator method.For all of these compounds, the observed pKa values decrease as the equilibrium enolate concentration is increased.It is proposed that this concentration dependence is a consequence of the aggregation of the enolates, and a method is described whereby average aggregation numbers can be determined from the acidity data.The results indicate that the extent of aggregation of enolate ions is influenced by both electronic and steric factors.In addition, internal solvation is found to be important for the lithium, but not the cesium enolate of o-methoxyacetophenone.
- Kaufman, Michael J.,Streitwieser, Andrew
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p. 6092 - 6097
(2007/10/02)
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- FORCE FIELD-SCF CALCULATIONS ON CYCLOPROPENE INTERMEDIATES IN CARBENE REARRANGEMENTS. COMPARISON WITH EXPERIMENT
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Heats of formation and geometries of benzocyclopropene, cyclopropa(b)naphthalene, bicyclo(4.1.0)hepta-2,4,7-triene, and benzannelated derivatives have been calculated with a combined force field-SCF progrsm.The bicycloheptatrienes are stabilized relative to the isomeric arylcarbenes by benzannelation, and destabilized by loss of aromaticity and/or increased strain. 1-Naphthylcarbene, 2-naphthylcarbene, 9-phenanthrylcarbene and 9-anthrylcarbene were generated by gas-phase pyrolysis of the corresponding arene aldehyde tosylhydrazone sodium salts, diazomethanes, or 5-aryltetrazoles, and rearranged to cyclobutanaphthalene(21), cyclobutaphenanthrene(33), and cyclobutaanthracene(38), respectively. 10,11-Dihydrodibenzocyclohepten-5-ylidene (15), similarly generated from 5-diazo-10,11-dihydro-5H-dibenzocycloheptene (39), rearranged to 5a,9b-dihydro-5H-benzocyclobutindene(40), 5H-dibenzocycloheptene(41), and 8,9-dihydro-4H-cyclopentaphenanthrene(40). 40 rearranged thermally to 41.The mechanisms of the rearrangements are discussed.
- Wentrup, Curt,Mayor, Claude,Becker, Juergen,Lindner, Hans Joerg
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p. 1601 - 1612
(2007/10/02)
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- PERI-METHANOARENES BY THERMOLYSIS OF TRIMETHYLSILANES
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Practical syntheses of varied peri-methanoarenes have been developed.
- Engler, T. A.,Shechter, H.
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p. 2715 - 2718
(2007/10/02)
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- The formation and reactions of 9,10-phenanthryne and related arynes by pyrolytic reactions in the vapor phase
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The formation of 9,10-phenanthryne (5), 4-methyl-9,10-phenanthryne (7) and 9,10-benz(c)phenanthryne (9) by the thermal degradation of appropriate arenedicarboxylic acid anhydrides has been investigated by a combination of VLPP and mass spectrometry and by a co-pyrolysis of the anhydrides with benzene, hexadeuterobenzene and 1,3-butadiene. Compounds 5,7 and especially 9 are formed easily by VLPP at 700-900° from the anhydrides. The results indicate that 7 and 9 are less reactive by H-addition to the aryne bond than 5, benzyne or naphthalyne, respectively. The results of the co-pyrolysis experiments show that 5 and 9 react with benzene and 1,3-butadiene by H-abstraction and addition reactions, similar to 1,2-benzyne and 2,3-naphthalyne. However, the reactivity of the aryne in the H-abstraction reaction decreases and the selectivity for the addition reaction increases in the series 1,2-benzyne, 2,3-naphthalyne, 9,10-phenanthryne and 9,10benz(c)phenanthryne.
- Gruetzmacher, Hans-Fr.,Strabtmans, Udo
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p. 807 - 813
(2007/10/02)
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- Some Reactions on 4H-Cyclopentaphenanthrene-8,9-dione
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The oxidation of 8,9-dihydro-4H-cyclopentaphenanthrene gave the 4-ketone by treatment with Triton B-oxygen, and afforded 8,9-diketone by the action of chromium (III) salt.The reduction of the quinone yielded the corresponding meso- and dl-diols.
- Yoshida, Masaaki,Kadokura, Atsushi,Minabe, Masahiro,Suzuki, Kazuo
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p. 1179 - 1180
(2007/10/02)
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- Cyclooctafluorene: A Planar Cyclooctatetraene Derivative. Paratropicity of Hydrocarbon and Anion
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The synthesis of cyclooctafluorene (1) from cyclopentaphenanthrene (5) is described.Hydrocarbon 1 shows paratropic antiaromatic character as deduced from the 1H NMR spectra and its low acidity (pKa = 27).The antiaromatic character of 1 is attributed to the presence of a planar cyclooctatetraene (COT) moiety.The deprotonation and the formation of cyclooctafluorenyl anion (13) are presented.The anion 13 exhibits paratropic character which may originate in peripheral delocalization of 16 ? electrons.
- Willner, Itamar,Rabinovitz, Mordecai
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p. 1628 - 1633
(2007/10/02)
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