Showing papers on "Fluorene published in 1969"
TL;DR: The absolute intensity of absorption parallel to the a and b axis of a fluorene crystal has been measured from 3000 to 2300 A and allowed the following interpretation to be placed on the solution spectrum: The 3000−A system of medium intensity and the stronger 2600-A system are longaxis polarized, and a rather weak band at about 2730 A is short-axis polarized as mentioned in this paper.
Abstract: The absolute intensity of absorption parallel to the a and b axis of a fluorene crystal has been measured from 3000 to 2300 A and allowed the following interpretation to be placed on the solution spectrum: The 3000‐A system of medium intensity and the stronger 2600‐A system are long‐axis polarized, and a rather weak band at about 2730 A is short‐axis polarized. The onset of a stronger short‐axis polarized transition above 2400 A was observed. This analysis shows that fluorene has quite different electronic properties from phenanthrene and carbazole. The low‐temperature absorption and fluorescence was entirely consistent with these electronic assignments. Vibrational analyses of the absorption and fluorescence spectra of fluorene in a polycrystalline n‐heptane matrix at about 15°K are presented; intervals that formed overtones were tentatively assigned as totally symmetric fundamentals. Crystalline fluorene did not measurably phosphoresce when pure, but intense, blue phosphorescence of fluorene could be in...
73 citations
TL;DR: The polarographic reduction of the arene-ironcyclopentadienyl compounds (arene = benzene, naphthalene, fluorene, diphenyl, phenanthrene) was investigated on the dropping mercury electrode as mentioned in this paper.
52 citations
TL;DR: In this article, the polarized infrared and Raman spectra of a single crystal of fluorene were reported over as wide an energy range as possible, and a partial assignment of the molecular fundamentals was given.
Abstract: The polarized infrared and Raman spectra of a single crystal of fluorene are reported over as wide an energy range as possible. Where this work has overlapped with a recently reported study the agreement has been satisfactory, although, with the data from the c‐polarized infrared spectrum and from the low‐frequency (50–400 cm−1) region presented here for the first time, several changes in the assignment of the molecular fundamentals are necessary. Some lattice modes of the fluorene crystal were found both in the infrared and Raman spectra and a partial assignment is given.
46 citations
TL;DR: In this paper, a long-range spin-spin coupling was derived from 60 and 100 Mc/s nuclear magnetic resonance spectra of 9 parent polycyclic hydrocarbons and 26 of their derivatives.
25 citations
TL;DR: Radioactive fluorene hydroperoxide has been identified in reaction mixtures hydroxylating [9-14C]fluorene and can be an intermediate in thehydroxylation of [ 9- 14C] Fluorene by rat liver homogenate.
22 citations
21 citations
15 citations
Patent•
05 Jun 1969
TL;DR: In this paper, the authors describe a system in which an ORGANIC PHOTOCONDUCTIVE system is combined with an array of $ ACID type ADDITIVES for the purpose of extending the SPECTRAL RESPONSE to the VISIBLE PORTION of the spectrum.
Abstract: ORGANIC PHOTOCONDUCTIVE SYSTEMS WHICH EMPLOY ORGANIC POLYMERS CONTAINING AROMATIC OR HETEROCYCLIC NUCLEI ARE COMBINED WITH AMOUNTS OF $ ACID TYPE ADDITIVES FOR THE PURPOSE OF EXTENDING THE SPECTRAL RESPONSE TO THE VISIBLE PORTION OF THE SPECTRUM. THE SENSITIZING COMPOUNDS ARE DIICYANOMETHYLENE SUBSTITUTED FLUORENES WHICH ARE ADDED IN AN AMOUNT EXPRESSED IN MOLES OF SENSITIZER PER 100 MOLES OF THE ORGANIC PHOTOCONDUCTOR CALCULATED AS THE MONOMER. THE AMOUNT OF SENSITIZER TO BE ADDED MAY RANGE FROM 0.1 TO ABOUT 100 MOLES PER 100 MOLES OF ORGANIC PHOTOCONDUCTOR BASED ON THE MOLECULAR WEIGHT OF THE MONOMER.
13 citations
TL;DR: In this paper, the delayed fluorescence has been observed in mixed crystals with a benz[f]indan guest in biphenyl host and also in fluorene host.
Abstract: Delayed fluorescence has been observed in mixed crystals with benz[f]indan guest in biphenyl host and also in fluorene host. At 77°K, the delayed fluorescence intensity shows a second‐order dependence on the phosphorescence intensity, indicating the biexcitonic origin of the delayed fluorescence observed. Temperature dependence of intensity and of decay and growth behavior of delayed fluorescence and phosphorescence is similar to that generally observed in mixed‐crystal systems where T1G < T1H < S1G < S1H. The thermal energy gap obtained from various Arrhenius plots, however, do not give the spectroscopic energy gap in either case; instead a lower activation energy has been obtained. Evidence is presented that an unknown impurity causes the delayed fluorescence in these cases. Kinetics for such guest‐impurity heterogeneous triplet–triplet annihilation is discussed.
13 citations
TL;DR: In this article, two synthesized cyclohepta [def]fluoren-8(4H)-one (XIX) are described; one involves ring enlargement of 4H-cyclophepta[def]phenanthrene (VIII) and the other cyclisation of fluorene-4-propioni acid (XXVII).
Abstract: Two syntheses of cyclohepta [def]fluoren-8(4H)-one (XIX) are described; one involves ring enlargement of 4H-cyclopenta [def]phenanthrene (VIII) and the other cyclisation of fluorene-4-propioni acid (XXVII). The 4H-cyclophepta[def]fluorenyl salts (XXIV) and (XXX) are not converted into cyclohepta[def]fluorene by reaction with pyridine or triethylamine and this is in accord with the predicted abnormally high nucleophilic reactivity of the 4-position of cyclohepta[def]fluorene. The heptafulvene (XLI) and the tropone (XIX) are evidently considerably more stable than their [def]fluorene tautomers (XLII) and (XX); this result is consistent with the calculated low π-electron energy of the cyclohepta[def]fluorene system.
13 citations
TL;DR: The 3200 A system of benz[ f ]indan has been fully characterized and corresponds to an 1 A 1 ← 1A 1 assignment, active along the long axis of the molecule, in analogy with the corresponding transition of naphthalene.
Patent•
09 Jan 1969
TL;DR: Novel fluorene and fluorenol bis-basic ester compounds, their method of preparation and use as antiviral agents, are presented in this paper, where the compounds are of the formula ##SPC1## wherein: A. each A is alkylene of two to about eight carbon atoms and separates its adjacent oxygen and nitrogen atoms by an alkyoline chain of at least two carbon atoms.
Abstract: Novel fluorene and fluorenol bis-basic ester compounds, their method of preparation and use as antiviral agents. The compounds are of the formula ##SPC1## Wherein: A. each of R1 and R2 is hydrogen, (lower) alkyl, cycloalkyl of three to six ring carbon atoms, alkenyl of three to six carbon atoms or each set of R1 and R2 taken together with the nitrogen to which they are attached is pyrrolidino, piperidino, N-(lower)alkylpiperazino or morpholino; B. each A is alkylene of two to about eight carbon atoms and separates its adjacent oxygen and nitrogen atoms by an alkylene chain of at least two carbon atoms; and C. x is H or OH; or a pharmaceutically acceptable acid addition salt thereof.
Patent•
30 Apr 1969
TL;DR: In this paper, the dibenzofluorenes and fluorenes are dispersed in suitable resin binders over the range of 1-100 parts by weight to 10 parts binder and applied to a conductive substrate.
Abstract: An organic photoconductor which is the compound fluorene and derivatives in which fluorene is fused with benzo and naphtho ring structures. The dibenzofluorenes and fluorenes are dispersed in suitable resin binders over the range of 1-100 parts by weight to 10 parts binder and applied to a conductive substrate.
TL;DR: In this article, a normal compound, 2,7,2,7′-dibromotribiphenylenepropane (IV), and an abnormal compound (V) were obtained by the Michael addition of 9,9,9′-bifluorenylidene (I) and 2, 7,2.2,2.,7.7.2.
Abstract: A normal compound, 2′,7′-dibromotribiphenylenepropane (IV), and an abnormal compound, 2′,7′,2″,7″-tetrabromotribiphenylenepropane (VI), were obtained by the Michael addition of 9,9′-bifluorenylidene (I) and 2,7-dibromofluorene (III). In addition, another normal compound, 2,7,2′,7′-tetrabromotribiphenylenepropane (VIII) and three abnormal compound, IV, VI, and tribiphenylenepropane (VII), were isolated by the Michael addition of 2,7,2′,7′-tetrabromo-9,9′-bifluorenylidene (IX) and fluorene (II). In both cases, the normal compounds were obtained in the presence of sodium ethoxide in ethanol. The abnormal compounds might be formed by the further condensation of 2,7-dibromo-9,9′-bifluorenylidene (V) and III or II in the presence of alkali. The related compounds, 2,7-dibromotribiphenylenepropane (X), IV, VI, VIII, and 2,7,2′,7′,2″,7″-hexabromotribiphenylenepropane, were synthesized by the reaction of substituted 9-fluorenyllithium and substituted 9-bromo-9,9′-bifluorenyl in an absolute xylene solution. The ther...
TL;DR: In this article, the linear bis-indenofluorene 13, 15-dihydro-11 H-diindeno [2, 1-b; 1′, 2′-h] fluorene (X) has been synthetised in 5 steps (overall yield 30%).
Abstract: Starting from cyclohexene and 2, 2′, 4, 4′-tetramethylbiphenyl the linear bis-indenofluorene 13, 15-dihydro-11 H-diindeno [2, 1-b; 1′, 2′-h] fluorene (X) has been synthetised in 5 steps (overall yield 30%). As an intermediate product the 11, 13, 15-trioxo-derivative IX was obtained. By a side way the 13-oxo-derivative of X and the already known monoangular bis-indenofluorene 13, 15-dihydro-5 H-diindeno [1, 2-a; 1′, 2′-h] fluorene (XIX) were also obtained.
TL;DR: The reaction of fluorene with alkali metals at -70° gives the fluorenyl anion as mentioned in this paper, which decays at higher temperatures to the fluorenes radical anion.
Abstract: The reaction of fluorene with alkali metals at –70° gives the fluorene radical anion. This decays at higher temperatures to the fluorenyl anion. The rate of the decay was found to be very sensitive to the nature of the counterion, i.e., ΔG‡ decreased markedly in the order Li+ > Na+ > K+ > Cs+. The decay can be of either the first or the second order, depending upon the nature of the counterion and of the solvent, and also on temperature. The e.s.r. spectrum of the radical anion has been studied and can be interpreted in terms of five sets of two equivalent protons.
TL;DR: The triplet lifetimes of a number of aromatic molecules dissolved in solid matrices at 77°K have been measured using a method of flash excited luminescence as discussed by the authors, which gave an accuracy of ± 1 % for the reported lifetimes.
Abstract: The triplet lifetimes of a number of aromatic molecules dissolved in solid matrices at 77°K have been measured using a method of flash excited luminescence. Statistical methods were employed which gave an accuracy of ±1 % for the reported lifetimes. The lifetimes of the aromatic species were constant in a range of n-aliphatic hydrocarbons. In n-heptane the lifetimes were in sec: phenanthrene 3.18; chrysene 2.44; fluorene 6.33; carbazole 7.16; dibenzothiophene 1.28. The lifetimes of these aromatics in a range of n-aliphatic alcohol solvents altered with the chain length of the solvent; a maximum lifetime was observed at n-propanol in each case followed by a decrease in lifetimes as the chain length increased. These changes in lifetime have been correlated with changes in the order and molecular packing of the solvent, which are believed to alter the radiationless decay process.
TL;DR: In this paper, a new synthesis of 6, 12-dihydro-indeno [1,2b] fluorene (trans-fluorenacene) was recorded.
Abstract: A new synthesis of 6, 12-dihydro-indeno [1,2-b] fluorene (trans-fluorenacene) in 9 steps starting from fluorene (overall yield 24,5%) is recorded. By partial oxidation of the hydrocarbon its 6-oxo derivative is also obtained.
Patent•
06 Aug 1969
TL;DR: In this paper, the authors show that Anthracene and fluorene can be oxidised in the liquid phase with 2 (-contg. gas) at room temp. -204 degrees C and 1 atm. -56 kg/cm2 in the presence of a salt of a heavy metal of at. no. 84 as catalyst.
Abstract: Anthracene (derivs.) and/or fluorene (derivs.) and opt. other cpds. are oxidised in the liquid phase with 02 (-contg. gas) at room temp. -204 degrees C and 1 atm. -56 kg/cm2 in the presence of a salt of a heavy metal of at. no. 84 as catalyst and also acid and pref. an inert diluent or solvent.
Patent•
15 Oct 1969TL;DR: The 9-FLUORENE CARBOXY-LIC ACID and DERIVATIVES as discussed by the authors was used for regulating plant growth in the early 1990s. But it was not suitable for large-scale applications.
Abstract: ESTERS OF 9-FLUORENE CARBOXYLIC ACID AND DERIVATIVES THEREOF USEFUL FOR REGULATING PLANT GROWTH.
TL;DR: In this article, a high yield (∼95%) was obtained upon metallation of fluorene with potassium tert-butoxide with subsequent treatment of the reaction mixture with methyl iodide in cation-solvating solvents: methylphosphonic acid tetramethyldiamide, hexamethapol, dimethyl sulfoxide, diglyme.
Abstract: 9, 9-Dimethylfluorene was obtained in high yield (∼95%) upon metallation of fluorene with potassium tert-butoxide with subsequent treatment of the reaction mixture with methyl iodide in cation-solvating solvents: methylphosphonic acid tetramethyldiamide, hexamethapol, dimethyl sulfoxide, diglyme.
TL;DR: In this paper, it has been shown that indanedione-1,3 gives 1,1-dimethyl-3-oxo- 1,2,3,9a-tetrahydro-9-indanedionylene fluorene in the presence of a base.
Abstract: It has been found that acetone and indanedione-1,3 gives 1,1-dimethyl-3-oxo-1,2,3,9a-tetrahydro-9-indanedionylene fluorene in the presence of a base, instead of 1,1-dimethyl-3-oxo-1,2,3,4-tetrahydro-9-indanedionylene fluorene or other products claimed in the literature. The nuclear magnetic resonance spectra of the product and some of its derivatives have been recorded.
TL;DR: The mechanisms of the formation of the products are discussed in this article, where the authors show that pyrolysis of diphenylmercury reacts with fluorene to give 9-phenylfluorene and 9,9′-bifluorenyl.
Abstract: Benzyl radicals, generated by the pyrolysis of dibenzylmercury, react with fluorene to give 9-benzylfluorene, 9,9-dibenzylfluorene, and 9,9′-bifluorenyl. Phenyl radicals, generated by the pyrolysis of diphenylmercury, react with fluorene to give 9-phenylfluorene and 9,9′-bifluorenyl. Homolytic benzylation of pyrene gives 1-benzylpyrene and 1,1′-bipyrenyl.The mechanisms of the formation of the products are discussed.