Showing papers on "Fluorene published in 1974"
56 citations
TL;DR: In this article, a study has been made of some correlations in the chemical cyclization of poly- (amino-acids) by treatment of the latter in solution in N,N-dimethylacetamide with a mixture of acetic anhydride and pyridine, taking the reaction between 3,3',4,4'- benzophenonetetracarboxylic acid dianhydride, and 9,9-bis-(4-aminophenyl)fluorene as an example.
Abstract: A study has been made of some correlations in the chemical cyclization of poly- (amino-acids) by treatment of the latter in solution in N,N-dimethylacetamide with a mixture of acetic anhydride and pyridine, taking the reaction between 3,3',4,4'- benzophenonetetracarboxylic acid dianhydride and 9,9-bis-(4-aminophenyl)fluorene as an example. Various other tertiary amines (pKa=4–11 were used in place of pyridine, in combination with acetic anhydride, for cyclization of poly(amino-acids). Polyimides were prepared by chemical cyclization of poly(amino-acids) in various organic media and it is shown that polyimides of high η1n are formed in solvents in which the poly(amido-acid) dissolves or swell.
22 citations
TL;DR: In this article, the two-photon excited fluorescence excitation spectrum is reported for naphthalene and 2,2-binaphthyl, and for fluorene and difluorenyl.
20 citations
TL;DR: In this paper, the reaction of hydrated electrons with naphthalene, phenanthrene, biphenyl and fluorene to form the respective aromatic radical anions has been studied in aqueous solutions (1 % methanol, pH 12.1).
Abstract: The reaction of hydrated electrons with naphthalene, phenanthrene, biphenyl and fluorene to form the respective aromatic radical anions has been studied in aqueous solutions (1 % methanol, pH 12.1) in the presence and absence of micellar hexadecyltrimethylammonium bromide (CTAB). The reaction rates are 3–9 times faster in the presence of micellar CTAB suggesting that CTAB will, in general, enhance this type of reaction. An absorption spectrum of the free fluorene radical anion was obtained. In the presence of CTAB the aromatic radical anions decay to second transients which are probably the hydrogen adducts of the aromatic molecules.
18 citations
Patent•
08 Jan 1974TL;DR: In this paper, a photoensitive material for electrophotography containing as a sensitizer the compounds of the formula was described, which was used in electrophotonography.
Abstract: Photosensitive material for electrophotography containing as a sensitizer the compounds of the formula:
13 citations
Patent•
21 Mar 1974TL;DR: Fluorenone can be prepared from fluorene by contacting a solution of the latter in dimethyl sulfoxide with molecular oxygen in the presence of a small amount of an alkali-metal hydroxide.
Abstract: Fluorenone can be prepared from fluorene by contacting a solution of the latter in dimethyl sulfoxide with molecular oxygen in the presence of a small amount of an alkali-metal hydroxide.
12 citations
TL;DR: In this paper, the title compound, 5, 6-dimethyl-7, 12-dihydroindeno[1,2-a]fluorene (IV), was synthesized in four steps (overall yield 9%).
Abstract: Starting from 3, 4-dimethylfluorene the title compound, 5, 6-dimethyl-7, 12-dihydro-indeno[1,2-a]fluorene (IV), is synthesized in four steps (overall yield 9%). The same hydrocarbon is also obtained in four steps starting from the phthalaconecarboxylic acid of Gabriel. This corroborates the structure of IV.
10 citations
TL;DR: In this paper, the fluorescence quenching of fluorene, dibenzofuran, and Dibenzothiophen by aliphatic amines and aromatic nitriles (electron acceptors) has been studied in different solvents.
8 citations
TL;DR: In this article, a simple kinetic scheme of the photophysical processes in the presence of a perturber with strong spin-orbit coupling is proposed, with a single parameter R 0 characterizing the sphere of interaction.
7 citations
TL;DR: Iodination of m- and p-toluic acid by successive reaction with thallium(III) trifluoroacetate and aqueous potassium iodide afforded 2-iodo-5-methyl- and 2-odo-4-methylbenzoic acid respectively; with o-toline acid 5- and 6-iodoe-2-methyl benzoic acids were obtained as mentioned in this paper.
Abstract: Iodination of m- and p-toluic acid by successive reaction with thallium(III) trifluoroacetate and aqueous potassium iodide afforded 2-iodo-5-methyl- and 2-iodo-4-methyl-benzoic acid respectively; with o-toluic acid 5- and 6-iodo-2-methylbenzoic acids were obtained. Reaction of the three o-iodo-acids with lithium diphenylcuprate and lithium di-(2-naphthyl)cuprate gave the corresponding aryltoluic acids. The naphthyl acids were used in the synthesis of 8-, 9-, and 10-methylbenzo[a]fluorene; the 7-methyl isomer was prepared by a separate procedure.
7 citations
Patent•
10 Apr 1974
TL;DR: In this paper, 9-Oxygenated fluorene-2-acetic acid derivatives and corresponding 9-halogenated derivatives and methods for preparing these derivatives are provided.
Abstract: 9-Oxygenated fluorene-2-acetic acid derivatives and corresponding 9-halogenated derivatives and methods for preparing these derivatives are provided. These compounds are useful as anti-inflammatory agents. In addition, a method for treating inflammatory conditions by administering these 9-substituted fluorene-2-acetic acid derivatives are provided.
TL;DR: The optical properties of the hydronaphthyl radicals produced upon radiolysis and photolysis of rigid naphthalene solutions in boric acid at 300 K and alcohol, ether and methylcyclohexane at 77 K were investigated in this paper.
TL;DR: The chalcone formed from salicylaldehyde and indoxyl cyclises in warm trifluoroacetic acid to yield the 5-oxonia-11-azabenzo[b]fluorene cation (Ib).
Abstract: The chalcone formed from salicylaldehyde and indoxyl cyclises in warm trifluoroacetic acid to yield the 5-oxonia-11-azabenzo[b]fluorene cation (Ib). The constitution of this has been confirmed by oxidation with hydrogen peroxide to the related flavone, [1]benzopyrano[3,2-b]indol-11-one (XI), also accessible by heating 2′-nitroflavone with ethyl phosphite.The chalcone from indoxyl and 2,4,6-triacetoxybenzaldehyde is converted by trifluoroacetic acid into the 7,9-dihydroxy-5-oxonia-11-azabenzo[b]fluorene cation (Ia). Formally, this cation can be regarded as a nitrogenous anthocyanidin, and the possibility of its occurrence in plants is discussed briefly.
TL;DR: In this paper, the treatment of 2-alkyl-1,4-naphthoquinones with t-butylamine resulted in dimerisation to give 12H-dibenzo[b,h]fluorene derivatives (II).
Abstract: Treatment of certain 2-alkyl-1,4-naphthoquinones with ethanolic t-butylamine resulted in dimerisation to give 12H-dibenzo[b,h]fluorene derivatives (II). Mixtures of these naphthoquinones gave low yields of mixed dimers of the same type.
TL;DR: In this article, non-enolizable carbonyl compounds were found to undergo intriguing reaction upon heating with hexamethylphosphoric triamide; benzophenone gave 1,1,2,2-tetraphenylethane and benz-phenone methylimine, while fluorenone afforded 9-methylfluorene, 9-dimethylamin-of-fluorene and fluorene.
Abstract: Non-enolizable carbonyl compounds were found to undergo intriguing reaction upon heating with hexamethylphosphoric triamide; benzophenone gave 1,1,2,2-tetraphenylethane and benzophenone methylimine, while fluorenone afforded 9-methylfluorene, 9-dimethylaminofluorene, and fluorene. In contrast, anthrone, an enolizable compound, was completely recovered unchanged under the the same reaction conditions.
TL;DR: In this article, a comparison of results of investigating a model π-complex of fluorene with pyromellitic anhydride and polyamides and polyimides prepared from diamines of the fluorenes series showed that in the indicated radicals of anhydide components have electron acceptor properties, while radicals of amine components behave as weak donors.
Abstract: A comparison of results of investigating a model π-complex of fluorene with pyromellitic anhydride and polyamides and polyimides prepared from diamines of the fluorene series showed that in the polymers indicated radicals of anhydride components have electron acceptor properties, while radicals of amine components behave as weak donors. With regular and dense packing of macro-chains, interaction may take place between aromatic nuclei with different electron densities of adjacent macromolecules.
TL;DR: In this paper, the equilibrium between contact ion pairs and solvent-separated ion pairs in the case of triphenylsilyl-lithium in dimethoxyethane has yielded the following thermodynamic constants.
Abstract: Previous studies of the reactions of triphenyl-, methyldiphenyl-, and dimethylphenyl-silyl-lithium with fluorene in tetrahydrofuran by the stopped-flow method have been extended by following the reaction of fluorene with triphenyl- and methyldiphenyl-silylsodium in tetrahydrofuran. It has been shown that in the change from Na+ to Li+ the increase in solvation of the initial state is more important than that of the transition state. A study of the equilibrium between contact ion pairs and solvent-separated ion pairs in the case of triphenylsilyl-lithium in dimethoxyethane has yielded the following thermodynamic constants: ΔG°= 1·98 kJ mol–1, ΔH°=–23·1 kJ mol–1, ΔS°=–86·0 J K–1 mol–1, at 20 °C.
TL;DR: In this article, the rates of detritiation of triphenlymethane, 9-phenylxanthene, fluorene and 9-ethylfluorene have been measured in ethanolic dimethyl sulfoxide (DMSO) containing sodium ethoxide.
Abstract: The rates of detritiation of triphenlymethane, 9-phenylxanthene, fluorene, 9-ethylfluorene, 9-phenylfiuorene, and 2,3-benzofluorene have been measured in ethanolic dimethyl sulfoxide (DMSO) containing sodium ethoxide When the logarithm of the ionization rate is plotted against the logarithm of the ionization rate of DMSO a straight line of near-to-unit slope is obtained in each case There are significant differences, however, between relative ionization rates and equilibrium acidities
TL;DR: Starting from 5-benzoyl-2,4-dibromobenzoic acid and 3-methyl-fluorene, a derivative of a mono-angular diindenofluorene has been synthesized in 5 steps.
Abstract: Starting from 5-benzoyl-2,4-dibromobenzoic acid and 3-methyl-fluorene, the 6-methyl-9,15-dihydro-7H-diindeno[2.1-b; 2′,1′-g]fluorene, a derivative of a mono-angular diindenofluorene has been synthesized in 5 steps (overall yield 1,5%).
Patent•
30 Sep 1974TL;DR: In this paper, the treatment of inflammatory conditions is a new use for certain known compounds; specifically, fluorene-2-acetic acid and its 7-halo, 7-amino, and 7-nitro derivatives.
Abstract: Novel fluorene-2-acetic acid derivatives and methods for preparing these derivatives are provided. Inflammatory conditions may be treated by administering these novel compounds. Additionally, it has been found that the treatment of inflammatory conditions is a new use for certain known compounds; specifically, fluorene-2-acetic acid and its 7-halo, 7-amino, and 7-nitro derivatives.
TL;DR: In this paper, rates of detritiation from the 9position of fluorene, 9-phenyl-, and 9-t-butyl-fluorene have been measured at 25° in hydroxide-water solutions containing various amounts of dimethyl sulphoxide.
Abstract: Rates of detritiation from the 9-position of fluorene, 9-phenyl-, and 9-t-butyl-fluorene have been measured at 25° in hydroxide–water solutions containing various amounts of dimethyl sulphoxide. In all three cases considerable rate enhancements are observed with the tendency being, as reflected in the log k vs. H_ correlations, for the weaker acid to be the more receptive to increases in basicity. These results are in accord with previous findings for other carbon acids.
TL;DR: By condensation according Ullmann of 2-iodo-9-oxo-fluorene with 3-bromo-2-cyano-9 -oxy-fluororene, followed by cyclisation and reduction, the new linear 13,15-dihydro-7H-diindeno[2.1-b; 2.1′-h]fluorenes (III) is synthesized in 3 steps as discussed by the authors.
Abstract: By condensation according Ullmann of 2-iodo-9-oxo-fluorene with 3-bromo-2-cyano-9-oxo-fluorene, followed by cyclisation and reduction, the new linear 13,15-dihydro-7H-diindeno[2.1-b; 2′.1′-h]fluorene (III) is synthesized in 3 steps. The 6-methyl-derivative of II is also obtained in a similar way.
TL;DR: In this article, the reaction of hydrated electrons with naphthalene, phenanthrene, biphenyl and fluorene to form the respective aromatic radical anions has been studied in aqueous solutions (1 % methanol, pH 12.1).
Abstract: The reaction of hydrated electrons with naphthalene, phenanthrene, biphenyl and fluorene to form the respective aromatic radical anions has been studied in aqueous solutions (1 % methanol, pH 12.1) in the presence and absence of micellar hexadecyltrimethylammonium bromide (CTAB). The reaction rates are 3–9 times faster in the presence of micellar CTAB suggesting that CTAB will, in general, enhance this type of reaction. An absorption spectrum of the free fluorene radical anion was obtained. In the presence of CTAB the aromatic radical anions decay to second transients which are probably the hydrogen adducts of the aromatic molecules.
TL;DR: The fluore-9-methanol esters of the 5′-phosphates of oligonucleotides are soluble in organic solvents, and the protected oligon nucleotides can be isolated by solvent extraction from the reaction mixture.
Abstract: The fluore-9-methanol esters of the 5′-phosphates of oligonucleotides are soluble in organic solvents, and the protected oligonucleotides can be isolated by solvent extraction from the reaction mixture.
TL;DR: In this paper, the authors measured the intensity of the bands of the stretching vibrations of the Si-H bond in the IR spectra of the organosilicon derivatives of fluorene and corresponding phenyl derivatives.
Abstract: We measured the intensity of the bands of the stretching vibrations of the Si-H bond in the IR spectra of the organosilicon derivatives of fluorene and the corresponding phenyl derivatives. A greater degree of dπ−pπ. interaction of the silicon atom with the aromatic rings was established in chlorosilafluorene than in diphenylchlorosilane. This is caused by the coplanarity of the rings of the fluorene fragment.
TL;DR: In this article, the rates of detritiation of triphenlymethane, 9-phenylxanthene, fluorene and 9-ethylfluorene have been measured in ethanolic dimethyl sulfoxide (DMSO) containing sodium ethoxide.
Abstract: The rates of detritiation of triphenlymethane, 9-phenylxanthene, fluorene, 9-ethylfluorene, 9-phenylfiuorene, and 2,3-benzofluorene have been measured in ethanolic dimethyl sulfoxide (DMSO) containing sodium ethoxide. When the logarithm of the ionization rate is plotted against the logarithm of the ionization rate of DMSO a straight line of near-to-unit slope is obtained in each case. There are significant differences, however, between relative ionization rates and equilibrium acidities.