- Net directed 180° aryl-aryl bond rotation in a prototypical achiral biaryl lactone synthetic molecular motor
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Net directed 180° bond rotation was achieved through diastereoselective ring-opening reactions in an achiral biaryl lactone using a chiral nucleophile followed by re-lactonization. The efficiency of the directed bond rotation has been determined by HPLC-MS to be 50% and 20% with two different chiral nucleophiles. These results demonstrate the potential for a prototype of a chemically driven synthetic molecular motor which has the advantages of both simplicity and flexibility in operation and is the first example of the use of a chiral auxiliary to induce transient axial chirality resulting in net directed bond rotation.
- Lin, Ying,Dahl, Bart J.,Branchaud, Bruce P.
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Read Online
- Photolysis of 10,10-difluorophenanthren-9(10H)-one. Evidence for solvent-assisted α-cleavage
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The photolysis of 10,10-difluorophenanthren-9(10H)-one 1 in different solvents shows that the major competing reaction of the diradical formed by α-cleavage: recombination and hydrogen atom abstraction depends on the hydrogen atom donating ability of the solvent. Photolysis of 1 in cyclohexane in the presence of air or oxygen leads mainly to α-cleavage while photoreduction with the formation of 10-fluoro-9-phenanthrol occurs when the solution is deaerated prior to irradiation. In acetonitrile, a poor hydrogen donor, recombination of the diradical back to starting compound 1 is the sole process.
- ?ket, Boris,Ko?mrlj, Berta,Harej, Maja,Dolenc, Darko
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Read Online
- Nitroaromatics as n-type organic semiconductors for field effect transistors
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The nitro group (NO2) is one of the most common electron-withdrawing groups but it has rarely been used in the design of organic semiconductors (OSCs). Herein, we report the n-type semiconducting behavior of simple fluorenone derivatives functionalized with NO2and CN groups. While the electron mobilities measured in the thin film field-effect transistors are modest (10?6-10?4cm2V?1s?1), the nitrofluorenone OSCs offer excellent air-stability and remarkable tunability of energy levelsviafacile modification of the substitution pattern. We study the effect of substituents on the electrochemical properties, molecular and crystal structure, and the charge transport properties of nitrofluorenones to revitalize the underestimated potential of NO2functionalization in organic electronics.
- Ghamari, Pegah,Hamzehpoor, Ehsan,Niazi, Muhammad Rizwan,Perepichka, Dmitrii F.,Perepichka, Igor F.
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supporting information
p. 6432 - 6435
(2020/06/21)
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- Poly(aryl ether ketone)s with carboxylic acid groups: Synthesis, sulfonation and crosslinking
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Carboxylic acid-containing poly(aryl ether ether ketone) (PFEEK-COOH) and poly(aryl ether ether ketone ketone) (PFEEKK-COOH) were synthesized from the monomer 9,9-bis(4-hydroxyphenyl)-fluoren-4-carboxylic acid. The latter polymer, PFEEKK-COOH, was post-sulfonated to yield SPFEEKK-COOH whereby the site and the degree of sulfonation (DS from 0 to 3) could be controlled. The reaction progress and structures of the resulting sulfonated polymers were identified by 1D and 2D NMR techniques. The carboxylic acid group was used as to crosslink SPFEEKK-COOH by reaction with poly(vinyl alcohol) (PVA) to prepare crosslinked membranes. The proton conductivity of a crosslinked SPFEEKK-COOH-1.6/PVA membrane was ~0.15 S cm-1 at 65 °C, while maintaining acceptable dimensional stability in water. Thermal stability, water uptake and proton conductivity of carboxylated, carboxylated/sulfonated, and crosslinked membranes were investigated.
- Liu, Baijun,Hu, Wei,Robertson, Gilles P.,Guiver, Michael D.
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scheme or table
p. 4675 - 4682
(2010/02/28)
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- Thio-substituted tricyclic and bicyclic aromatic methanesulfinyl derivatives
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The present invention is related to chemical compositions, processes for the preparation thereof and uses of the composition. Particularly, the present invention relates to compositions of compounds of Formula (A): wherein Ar, Y, R1 and q are as defined herein; and their use in the treatment of diseases, including treatment of sleepiness, promotion of wakefulness, treatment of Parkinson's disease, cerebral ischemia, stroke, sleep apneas, eating disorders, stimulation of appetite and weight gain, treatment of attention deficit hyperactivity disorder ("ADHD"), enhancing function in disorders associated with hypofunctionality of the cerebral cortex, including, but not limited to, depression, schizophrenia, fatigue, in particular, fatigue associated with neurologic disease, such as multiple sclerosis, chronic fatigue syndrome, and improvement of cognitive dysfunction.
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Page/Page column 27
(2008/06/13)
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- Organophotoreceptor with a compound having a toluidine group
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An improved organophotoreceptor comprises an electrically conductive substrate and a photoconductive element on the electrically conductive substrate wherein the photoconductive element comprisesa) a charge transport material with the following formula where R1 and R2 are, independently, a carbazolyl group, an (N,N-disubstituted) aminoaryl group, such as a triphenyl amine group, or a julolidine group, and R3 and R4 are, independently, hydrogen, branched or linear alkyl group (e.g., a C1-C20 alkyl group), branched or linear unsaturated hydrocarbon group, cycloalkyl group (e.g. cyclohexyl group), or aryl group (e.g., phenyl group, naphthyl group, stilbenyl group, (9H-fluoren-9-ylidene)benzyl group, or tolanyl group);(b) an optional charge transport compound; and(c) a charge generating compound.
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- Organophotoreceptor with charge transport compound having an epoxy group
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This invention relates to a novel organophotoreceptor that comprises an electrically conductive substrate and photoconductive element on the electrically conductive substrate, the photoconductive element having a) a novel charge transport compound having the formula where X is a divalent hydrocarbon group of 1 to 30 carbon atoms, or a divalent hydrocarbon group of 1 to 30 carbon atoms where there is at least one substitution of a carbon atom by a heteroatom provided that no two heteroatoms may be adjacent within the backbone of an aliphatic divalent hydrocarbon radical, R1 is an aryl group or a heterocyclic group, R2 is a (N,N-disubstituted)arylamine group, and R3 is an epoxy group; and (b) a charge generating compound. The epoxy group can be reacted with a functional group within the polymer to form a polymeric charge transport compound either directly or through a crosslinking agent.
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- Linked dihydrazone-based charge transport compounds
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This invention relates to a novel organophotoreceptor that includes: (a) a charge transport compound having the formula where n is an integer from 0 to 1 inclusive; X is an (N,N-disubstituted)arylamine, such as a carbazole group, a julolidine group, or a p-(N,N-disubstituted)arylamine group (which can be a triarylamine, an alkyldiarylamine or a dialkylarylamine); Ar is an aryl group or a heterocyclic group; A is a linking group having the formula —S—(CH2)m—S— where m is an integer from 1 to 15 inclusive and; B is a second linking group with the formula —(CH2)p— which can be branched or linear, where p is an integer from 3 and 20 inclusive and where one or more methylene groups can be optionally replaced by O, S, a carbonyl group, urethane, urea, an ester group, a —NR21 group, a CHR22 group, or a CR23R24 group where R21, R22, R23 and R24 are, independently, H, hydroxyl, thiol, an amine group, an alkyl group, an alkaryl group, an aryl group, or part of a ring; (b) a charge generating compound; and (c) an electrically conductive substrate over which the charge transport compound and the charge generating compound are located.
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- Linked dihydrazone-based charge transport compounds
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Improved organophotoreceptors comprise: (a) a charge transport compound having the formula where n is an integer from 0 to 1; X is an (N,N-disubstituted)arylamine group; Ar is an aryl group or a heterocyclic group; A is a first linking group with the formula —(CH2)p— which can be branched or linear, where p is an integer from 3 to 20 inclusive and where one or more methylene groups can be optionally replaced by O, S, a carbonyl group, urethane, urea, an ester group, a —NR21 group, a CHR22 group, or a CR23R24 group where R21, R22, R23 and R24 are, independently, H, hydroxyl, thiol, an amine group, an alkyl group, an alkaryl group, an aryl group, or part of a ring; and B is a second linking group having the formula -Q-Z-Q′-, where Q and Q′ are, independently, O, S, or NR1; wherein when Q or Q′ is NR1 or Q=O and Q′=S, Z comprises an aryl group, and wherein when Q=Q′=S or Q=Q′=O, Z comprises a multi-ring conjugated group or —Y—W—Y′— wherein Y and Y′ comprise, independently, an aryl group and W comprises a CR2R3 group; wherein R1 is hydrogen or comprises an alkyl group or an aryl group; R2 is a hydrogen or comprises an alkyl group, or an aryl group; and R3 comprises an alkyl group or an aryl group or may form a ring structure along with the R2 group; (b) a charge generating compound; and (c) an electrically conductive substrate over which said charge transport compound and said charge generating compound are located.
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- Nafion-H catalysed intramolecular Friedel-Crafts acylation: Formation of cyclic ketones and related heterocycles
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Benzoic acids with suitable substituents bearing phenyl ring in the ortho position undergo cyclization by intramolecular Friedel-Crafts acylation in the presence of Nafion-H, a perfluorinated resinsulfonic acid catalyst. Synthesis of anthraquinone, anthrone, fluorenone, α-tetralone, 1-benzosurberone and heterocycles such as acridone, xanthone etc. is easily achieved in good to excellent yields (82-95%) by this method.
- Olah, George A.,Mathew, Thomas,Farnia, Morteza,Prakash, G. K. Surya,Katherine,Donald
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p. 1067 - 1068
(2007/10/03)
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- Synthesis and structural assignment of 2,4′-disubstituted benzylidenefluorenes and 4′-substituted benzylidene-1-azafluorenes
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In the course of a study aimed at the investigation of edge-to-face arene-arene interactions, substituted benzylidenefluorenes 8-16 and benzylidene-1-azafluorenes 20-24 were synthesized as mixtures of E-Z-isomers. The full structural assignment of these compounds, performed by 2D NMR experiments, is described together with a study of their E-Z isomerization under equilibrating conditions. For compounds 8-16 no correlation was observed between the electron-donating or electron-withdrawing nature of the substituent groups and the E/Z equilibrium ratios. In the case of 20-24 the predominance of the E-isomers seems to depend exclusively on the N-lone pair-benzylidene ring electronic repulsion rather than on the nature of the para substituent on the aromatic ring.
- Annunziata, Rita,Molteni, Valentina,Raimondi, Laura
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p. 520 - 528
(2007/10/03)
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- Acid-Catalyzed Cyclization of o-Aroylbenzoic and Diarylcarboxylic Acids upon Heating in Vacuum
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The cyclization of 1,1′-dinaphthyl-8,8′-dicarboxylic acid, diphenic anhydride, o-benzoylbenzoic acid, and 1-naphthoyl-o-benzoic acid into, respectively, anthanthrone, fluorenone-4-carboxylic acid, anthraquinone, and 1,2-benzanthraquinone occurs upon heating to 150-200°C in vacuum in the presence of catalytic amounts (1-3%) of H2SO4 or P2O5.
- Nefedov
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p. 375 - 377
(2007/10/03)
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- Formation of cyclopent[a]indene and acenaphthylene from allyl esters of biphenyl mono- and di-carboxylic acids and from biphenyl dicarboxylic anhydrides on flash vacuum pyrolysis at 1000-1100°C
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Flash vacuum pyrolysis at 1000-1100°C of the allyl esters of the three isomeric biphenylcarboxylic acids, of the allyl esters of the 12 biphenyldicarboxylic acids and of the three biphenyldicarboxylic anhydrides gave pyrolysates which were examined by 1H n.m.r. spectroscopy at temperatures below -50°C. In all cases the spectra showed the presence of cyclopent[a]indene and acenaphthylene together with other products. Possible mechanisms for these ring contraction and cyclization processes are discussed and the results of pyrolyses of [2,3-13C2]biphenyl-2,3-dicarboxylic anhydride, and [3,4-13C2]-and (2-2H1)-biphenyl-3,4-dicarboxylic anhydrides are reported.
- Bapat, Jayant B.,Brown, Roger F.C.,Bulmer, Glenn H.,Childs, Trevor,Coulston, Karen J.,Eastwood, Frank W.,Taylor, Dennis K.
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p. 1159 - 1182
(2007/10/03)
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- Synthesis of electrophore-labeled oligonucleotides and characterization by matrix-assisted laser desorption/ionization mass spectrometry
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Recent work to apply mass spectrometric methods to DNA analysis has led to the attachment of an electrophore to an oligonucleotide primer, with the purpose of investigating whether the advantages of electron capture ionization (increased ionization efficiency, reduced fragmentation) could be extended to larger molecules, such as Sanger sequence ladders. The stability of the electrophore-modified primers under conditions encountered during matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) was investigated. Four different electrophore labels were successfully attached to the 5' terminus of a 17-base, single-stranded oligodeoxyribonucleotide sequencing primer. The attached electrophore tags are robust under conditions used for sample preparation and MALDI-MS, and little or no fragmentation resulting from loss of the electrophore was observed. While no sensitivity enhancement was observed for the electrophore-labeled DNA, mass spectrometric conditions are discussed under which the electrophore labels could enhance the detection of DNA sequencing ladders.
- Britt, Phillip F.,Hurst, Gregory B.,Buchanan, Michelle V.
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p. 661 - 668
(2007/10/03)
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- Preneoplastic lesions, DNA adduct formation and mutagenicity of 5-, 7- and 9 -hydroxy-2-nitrofluorene, metabolites of the air pollutant 2-nitrofluorene
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The metabolites of 2-nitrofluorene (NF), 5-, 7- and 9-OH-2-nitrofluorene (OH-NF) were compared for their genotoxicity. Seventy-two hours after intraperitoneal administration of these substances individually to rats (100 mg/kg body wt.), DNA adducts in liver tissue were analyzed with 32P-TLC and 32P-HPLC. An in vivo liver model was used to test the initiating capacity of the said substances for the formation of preneoplastic lesions. 5-OH-NF showed low capacity to induce DNA adduct formation and low potential as initiator to induce preneoplastic lesions-foci/nodules in the liver of rats. Both 7- and 9-OH-NF induced DNA adducts and preneoplastic liver lesions but with smaller quantities compared to NF. It seems that 7- and 9-OH-NF can not be considered as detoxification products of NF. In general, the initiating capacity of these substances for the formation of preneoplastic lesions has a good correlation with their potency to form DNA adducts.
- Cui, Xian-Shu,Bergman, Jan,Moeller, Lennart
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p. 147 - 155
(2007/10/03)
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- TRINITRO-9-OXOFLUORENECARBOXAMIDES AS CHIRAL ELECTRON ACCEPTORS
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Trinitrofluorenecarboxamides, labeled with optically active α-phenylethylamine and some of its derivatives, were synthesized in a continuation of researches into new chiral electron acceptors of the nitrofluorene series.Their possible use as chiral acceptors in the resolution of compounds into enantiomers by chromatographic separation of diastereomeric charge-transfer complexes was investigated.
- Il'ina, I.G.,Ivanova, E.V.,Sokolova, E.L.,Mikhalev, O.V.
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p. 266 - 269
(2007/10/02)
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- 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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p. 2179 - 2180
(2007/10/02)
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