Showing papers on "Fluorenone published in 2019"

Stability of Hydrocarbon Fuel Cell Membranes: Reaction of Hydroxyl Radicals with Sulfonated Phenylated Polyphenylenes

Abstract: The perceived poor durability of hydrocarbon polymer electrolyte membranes remains a significant hurdle for the integration of nonfluorous, solid polymer electrolytes into electrochemical systems such as fuel cells. In order to elucidate the mechanism of free radical degradation in a promising class of hydrocarbon polymer electrolyte membranes based on sulfonated phenylated polyphenylenes (sPPP), we synthesized and studied the degradation of a structurally analogous oligophenylene model compound in the presence of hydroxyl radicals using NMR spectroscopy and mass spectrometry. Degradation is demonstrated to be initiated by the oxidation of pendant phenyl rings to carboxylic acids, which form fluorenone substructures via intramolecular reaction with a juxtaposed phenyl ring. Upon further oxidation, these substructures can lead to ring-opening of a core phenyl ring which, if occurring in sPPP, leads to chain-scission of the polymer backbone. In keeping with this hypothesis, molecular weights of sPPP are fou...

Halogen Substituent Effects on Concentration-Controlled Self-Assembly of Fluorenone Derivatives: Halogen Bond versus Hydrogen Bond

Abstract: Self-assembled behaviors of three fluorenone derivatives substituted by different halogen atoms, 2-(pentadecyloxy)-6-bromo-fluorenone (Br-FC15), 2-(pentadecyloxy)-6-chloro-fluorenone (Cl-FC15), and...

Design, Synthesis, and Properties of Donor–Acceptor–Donor′ Asymmetric Structured Electrochromic Polymers Based on Fluorenone as Acceptor Units

Abstract: Two novel conjugated polymers based on a donor–acceptor–donor′ (D–A–D′) asymmetric structure, using fluorenone as the acceptor unit linked with different donor units on both sides, were designed and synthesized, namely poly2-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-7-(thiophen-2-yl)-9H-fluoren-9-one (PSWE) and poly2-(4-(diphenylamino)phenyl)-7-(thiophen-2-yl)-9H-fluoren-9-one (PSWT). Compared with the symmetrical structure polymer poly(2,7-dithiophen-2-yl)-fluoren-9-one (PSWS), the asymmetric structure polymers exhibit lower redox potentials and bandgap values and more redox peaks and thus showed a richer variety of colors. Moreover, the introduction of 3,4-ethylenedioxythiophene improved PSWE’s response speed under the near-infrared–visible band and enhanced its optical contrast in the near-ultraviolet spectrum. The introduction of triphenylamine improved PSWT’s optical contrast in the near-infrared and visible spectra. It could be inferred that the polymers with asymmetric structure (D–A–D′) exhibit m...

Effect of One- and Two-Electron Reduction of Terbium(III) Double-Decker Phthalocyanine on Single-Ion Magnet Behavior and NIR Absorption.

Abstract: Reduction of terbium(III) double-decker phthalocyanine, TbIIIPc2 (1), by sodium fluorenone ketyl in the presence of bis(triphenylphosphoranylidene)ammonium cations yields one-electron-reduced (PPN+...

Bromine Substituent Position Triggered Halogen versus Hydrogen Bond in 2D Self-Assembly of Fluorenone Derivatives

Abstract: A systematic investigation on the bromine substituent position effects on the self-assembly of fluorenone derivatives 1-bromo-7-(pentadecyloxy)-fluorenone (1-BFC15), 2-(pentadecyloxy)-7-bromo-fluor...

Reversible Hydrogen Releasing and Fixing with Poly(Vinylfluorenol) through a Mild Ir‐Catalyzed Dehydrogenation and Electrochemical Hydrogenation

Abstract: The radical polymerization of 2-vinylfluorenol, an alcohol derivative of vinylfluorene, gives poly(vinylfluorenol), which quantitatively releases hydrogen gas (≈110 mL per gram polymer at standard temperature and pressure) by simply warming at 100 °C with an iridium catalyst. A high population of fluorenol units in the polymer accomplishes a large formula-weight-based theoretical hydrogen density (1.0 wt%). The dehydrogenated ketone derivative, poly(vinylfluorenone), exhibits reversible negative-charge storage with a high density of 260 mAh g-1 . The electrolytically reduced poly(vinylfluorenone) is momentarily hydrogenated in the presence of an electrolyte with water as the hydrogen source to be converted to the original poly(vinylfluorenol). The formed poly(vinylfluorenol) almost quantitatively evolves hydrogen gas similar to the starting poly(vinylfluorenol). Both hydrogen and charge storage with the organic fluorenol/fluorenone polymer suggest a new type of energy-storage configuration.

Aerobic oxidation of fluorene to fluorenone over Co–Cu bimetal oxides

Abstract: Oxidation of sp3 C–H bonds has attracted increasing attention, and the aim of our work is to prepare catalysts for oxidation of sp3 C–H bonds using O2 without an initiator. In this paper, a series of Co–Cu bimetal oxides with different Co/Cu ratios were synthesized by a sol–gel method and tested for catalytic oxidation of fluorene to fluorenone using molecular oxygen as an oxidant in the absence of a radical initiator. The best catalytic performance was achieved over the Co0.7Cu0.3 catalyst and the catalysts could be reused without significant loss of the catalytic activity. The characterization results indicated that some Cu entered the Co3O4 lattices, leading to more high-valence metal ion sites (Co3+ and Cu2+) and surface oxygen species (O2−, O22−, and O−) as well as promoted redox ability, which all enhanced the catalytic activity. In addition, the catalysts were also efficient for the oxidation of other benzylic C–H containing aromatic hydrocarbons such as tetralin, indan, diphenylmethane and ethylbenzene.

Synthesis and properties of four new two-photon polymerization initiators with expanded conjugated structures

Abstract: Four new two-photon polymerization initiators have successfully synthesized with D–π–A–π–D type structure in which the carbazole or phenothiazine moiety acts as a donor, phenylacetylenyl as a conjugate linker and the Fluorenone or thioxanthone as an acceptor. These four compounds exhibited low fluorescence quantum yields (Φ) of FT-CAA-C6 (1.65%), FT-PTAA-C6 (0.01%), TX-CAA-C6 (3.56%) and TX-PTAA-C6 (0.02%) in dichloromethane. And, the δTPA values of FT-PTAA-C6 reached a maximum value of 527 GM. In addition, three-dimensional woodpile microstructure was fabricated via two-photon polymerization using FT-CAA-C6 as an initiator which possessed potential applications due to simple preparation.

Energetics and ionization dynamics of two diarylketone molecules: benzophenone and fluorenone

Abstract: Single photon ionization and subsequent unimolecular ion decomposition were studied on jet-cooled benzophenone and fluorenone separately, using VUV synchrotron radiation in a photoion/photoelectron coincidence setup. Slow PhotoElectron Spectra (SPES) were recorded in coincidence with either the parent or the fragment ions for hν < 12.5 eV. Dissociative ionization is observed for benzophenone only. The full interpretation of the measurements, including the identification of the neutral and ionic species when dissociative ionization is at play, benefits from high level ab initio computations for determining the equilibrium structures and the energetics of the neutral and ionized molecules and of their fragments. Electronically excited states of the parent molecular ions were calculated also. From this analysis, an accurate experimental determination of the energetics of the benzophenone and fluorenone ions and of their fragmentation channels is available: adiabatic ionization energies of benzophenone at 8.923 ± 0.005 eV and of fluorenone at 8.356 ± 0.007 eV; and appearance energies of benzophenone fragment ions at 11.04 ± 0.02 eV (loss of C6H5), 11.28 ± 0.02 eV (loss of H) and 11.45 ± 0.02 eV (loss of CO). The corresponding fragmentation mechanisms are explored, showing likely concerted bonds rearrangement. Possible pre-ionizing fragmentation is discussed in light of the spectra presented. The structural rigidity of fluorenone diarylketone seems to be the origin of the inhibition of the fragmentation of its cation.

Iodine-mediated synthesis of benzo[a]fluorenones from yne-enones

Abstract: The chalcones derived from o-alkynylacetophenones and aromatic aldehydes (yne-enones) when heated under reflux with iodine in acetic acid gave a range of benzo[a]fluorenone derivatives in moderate to good yields. The transformation involves the formation of a vinyl indenone intermediate through regioselective alkyne hydration and intramolecular aldol condensation followed by electrocyclic ring closure and aromatization.

A New Fluorenone-based Turn-on Fluorescent Al3+ Ion Sensor

Abstract: In this paper, we report a turn-on fluorescence sensing of Al3+ ion using a new fluorenone derivative. The imino derivative of 2-amino-9-fluorenone and mercapto-2-butanone is synthesized and characterized using IR, NMR, and mass spectral techniques. The fluorescence of the compound shows a large enhancement at the addition of Al3+ ions, and other metal ions show insignificant changes of the fluorescence. The stoichiometry and the binding constant of the complex are reported. The detection limit of the Al3+ determination by the fluorenone derivative is 5 × 10–8 M. A visible enhancement of color occurs on illumination of the fluorescent compound – Al3+ ion complex.

Synthesis and characterization of 9,9-bis(4-hydroxyphenyl and 4-aminophenyl)dibenzofluorenes: Novel fluorene-based monomers

Abstract: Two novel 9,9‐difunctionalized fluorene‐type monomers, 9,9‐bis(4‐hydroxyphenyl‐ and 4‐aminophenyl)‐2,3:6,7‐dibenzofluorenes, are synthesized by the reaction of dibenzenzofluorenone with phenol and aniline. These monomers are used for the preparation of polyester and polyimide as the typical polymers to evaluate the property change such as thermal stability caused by the benzene rings fused to the fluorene skeleton with keeping good solubility, in comparison with the polymers derived from simple fluorenone. In fact, these two new polymers have the fairly enhanced thermal stability and refractive index value along with satisfactory solubility in organic solvents, enough to emphasize the fusion effect. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2602–2605

Catalyst for synthesizing fluorenone and preparation method and application thereof

Abstract: The invention relates to a catalyst for synthesizing fluorenone and a preparation method and application thereof, and belongs to the technical field of catalysts. The catalyst is prepared from, by mass, 0-100% of tri-cobalt trioxide and 0-100% of copper oxide, and the sum of the mass percentages of the tri-cobalt trioxide and the copper oxide is 100%; the catalyst for synthesizing the fluorenone is prepared by a sol-gel method or a gel method. The catalyst has the advantages of low cost, high conversion rate, high selectivity, mild reaction condition, good stability and easy separation of reactants.

Fluorenone-based organic gel molecule and preparation method and application thereof

Abstract: The invention belongs to the technical field of gel materials and provides a fluorenone-based organic gel molecule and a preparation method and application thereof. A fluorescent sensing film preparedfrom the fluorenone-based organic gel molecules can be used for aniline steam detection. In preparation of the sensing film, the fluorenone-based organic gel molecules form a three-dimensional spatial net structure through intermolecular self assembly, the intrinsic specific surface area of the film is increased, and aniline steam adsorption capacity of the film is increased. By photo-induced electron transfer between the adsorbed aniline steam and the fluorenone-based organic gel molecules, fluorescence quenching of the fluorescent sensing film occurs and is intensified along with increasingof aniline steam. The aniline concentration is detected according to the relation between the aniline concentration and fluorescence quenching of the fluorescent sensing film.

Method for separating fluorene and fluorenone by cooling crystallization and particle size classification

Abstract: The invention relates to a method for separating fluorene and fluorenone by cooling crystallization and particle size classification. The method comprises the following steps: adding a mixture of thefluorene and the fluorenone into a solvent, performing stirring, performing heating to 40-50 DEG C for dissolution, after the solid is completely dissolved, performing cooling gradually to 20-35 DEG C, only adding a fluorenone seed crystal into the solution, continuing cooling to 0-10 DEG C, performing filtration on crystal slurry, performing drying to obtain a crystal mixture, after drying is performed, performing sieving on the crystal mixture by using a standard sieve with different meshes, and classifying the mixture into three levels according to particle size distribution results, wherein different particle size levels correspond to fluorine or fluorenone with different purity. The method provided by the invention can realize effective separation of low eutectic composition of the fluorene and the fluorenone, and obtain the fluorene and fluorenone crystal products with higher purity; and the method is simple and safe and has low costs.

Fluorene or fluorenone containing functional diamine monomer with high planarity as well as synthesis method and application thereof

Abstract: The invention discloses a fluorene or fluorenone containing functional diamine monomer as well as a synthesis method and application thereof. The method utilizes halogen atoms of dihalogenated fluorene or fluorenone to react with amino to form secondary amine; or utilizes dihalogenated fluorene or fluorenone to obtain acyl chloride through cyaniding, hydrolysis and acylating chlorination, and thenutilizes acryl chloride and amino to form an amido bond; or utilizes dinitrofluor or fluorenone to obtain amino, and then utilizes amino and isocyanate to form a urea bond; or utilizes dihalogenatedfluorene or fluorenone to obtain amino through Suzuki and reduction, and then utilizes amino and halogen atoms to form secondary amine; or utilizes dihalogenated fluorene or fluorenone to react with hydroxy to form an ether bond, and finally binitro containing secondary amine, the amide bond, the urea bond and the ether bond is reduced to be diamine. The minimum energy state 3D structure of the diamine monomer has the high planarity, and diamine can be taken as monomers to prepare polymers such as polyamide, polyimide, polyamide-imide and polyureas-imide with the high mutual acting force amongmolecular chains and small free volume.

Fluorenone derivative, and preparation and application thereof

Abstract: The invention discloses a fluorenone derivative, and preparation and application thereof. The fluorenone derivative takes a fluorenone structure containing electron deficiency carbonyl groups as a core, and an aromatic fused ring compound with the electron deficiency characteristic is further bridged to form a compound with high hole transfer. The fluorenone derivative serving as a hole transfer material and a luminous layer main body material of an OLED device has the advantages of remarkably improved performance of the device in starting voltage, luminous intensity, external quantum efficiency, current efficiency, power efficiency, chromaticity, half-life and the like, and enhanced working stability of the device.

Conjugated polymer and preparation method thereof

Abstract: The invention belongs to the field of polymer, and relates to a conjugated polymer and a preparation method thereof. The conjugated polymer has a structure as shown in a formula I, wherein -Ar- is arylidene, heteroarylidene or chemical bond, n is more than or equal to 5, and optimally 5; R is at least one of H, halogen, trimethylacetic radical OPiv, acetyl OAc and trifyl OTf. The method for synthesizing the conjugated polymer by using fluorenone as a main block is scientific and reasonable, can be used for synthesizing the conjugated polymer by using fluorenone as the main block, which cannotbe obtained in a one-step reaction by other methods, and has the characteristics of simple synthesis method, high yield, easily purified product and the like.