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Fluorene

About: Fluorene is a research topic. Over the lifetime, 5656 publications have been published within this topic receiving 103627 citations. The topic is also known as: Fluoren & o-biphenylenemethane.


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Journal ArticleDOI
TL;DR: This review focuses on bacterial degradation pathways of selected aromatic compounds and describes proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.
Abstract: Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

791 citations

Journal ArticleDOI
TL;DR: In this article, the particular properties of soluble derivatives of polyfluorene homopolymers with respect to emission properties, control of color stability and efficiency in electroluminescence, alignment in thin layers and polarized emission are discussed.
Abstract: Since the first report on blue electroluminescence from a soluble poly(9,9-di-alkylfluorene), fluorene-based homo- and copolymers have evolved as a major class of polymeric emitters for highly efficient organic light-emitting diodes. This Review is concerned with the particular properties of soluble derivatives of polyfluorene homopolymers with respect to emission properties, control of color stability and efficiency in electroluminescence, alignment in thin layers and polarized emission. A major point of discussion is the origin of unwanted emission contributions in the photoluminescence and electroluminescence spectra of solid layers as well as concepts to avoid these contributions in order to ensure stable device performance. Further, the alignment of polyfluorenes and their use in polarized light-emitting diodes is addressed.

787 citations

Journal ArticleDOI
TL;DR: In this article, a brief overview of organic electroluminescence and electrophosphorescence is provided, and a more detailed consideration of ways in which electron transport in these systems has been enhanced by the incorporation of electron-deficient small molecules and polymers into the devices, either as blends or by covalent attachment of sub-units to the luminophore or as an additional electron-transporting, hole-blocking (ETHB) layer adjacent to the cathode.
Abstract: One of the requirements for efficient organic electroluminescent devices (OLEDs) is balanced charge injection from the two electrodes and efficient transport of both holes and electrons within the luminescent layer in the device structure. Many of the common luminescent conjugated polymers, e.g. derivatives of poly(phenylenevinylene) and poly(fluorene), are predominantly hole transporters (i.e. p-dopable). This article gives a brief overview of organic electroluminescence and electrophosphorescence and provides a more detailed consideration of ways in which electron transport in these systems has been enhanced by the incorporation of electron-deficient (i.e. n-dopable) small molecules and polymers into the devices, either as blends or by covalent attachment of sub-units to the luminophore or as an additional electron-transporting, hole-blocking (ETHB) layer adjacent to the cathode. The chemical structures of these systems are presented and their roles are assessed. Most of these ETHB molecules are electron-deficient aromatic nitrogen-containing heterocycles, e.g. derivatives of 1,3,4-oxadiazole, pyridine, pyrimidine, pyrazine, quinoline, etc. Non-aromatic thiophene-S,S-dioxide derivatives are also discussed. The article is written from an organic chemist's perspective.

599 citations

Journal ArticleDOI
TL;DR: In this article, palladium-catalyzed couplings between various 9,9-disubstituted poly(2,7-dibromofluorenes) have been used to obtain process-able polyfluorenes in good yields.
Abstract: Well-defined poly(2,7-fluorene) derivatives have been prepared through palladium-catalyzed couplings between various 9,9-disubstituted or 9-monosubstituted 2,7-dibromofluorenes and 2,7-bis(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9-dioctylfluorene. Using this versatile synthetic method, process- able polyfluorenes have been obtained in good yields. In solution, all these neutral yellow polymers exhibit blue emission (maximum of emission around 410 nm) with high quantum yields (up to 0.87). Moreover, novel acidic polyfluorene derivatives have been synthesized (i.e., poly(2,7'-(alkyl 9,9-dioctyl-7,2'-bifluorene- 9'-carboxylate))s) which show, upon base doping, electrical conductivities of 10-6-10-5 S/cm. This new doping method for conjugated polymers could open the way to the preparation of air-stable electron- injecting electrodes. Both photophysical and electrical properties of these polymers are quite promising for the fabrication of efficient blue-light-emitting devices.

578 citations

Journal ArticleDOI
TL;DR: The electrochemical oxidation of aromatic heterocyclic compounds thiophene, pyrrole, and indole and benzenoid and nonbenzenoid polycyclic hydrocarbons azulene, fluorene, and pyrene yield electrical...
Abstract: The electrochemical oxidation of aromatic heterocyclic compounds thiophene, pyrrole, and indole and benzenoid and nonbenzenoid polycyclic hydrocarbons azulene, fluorene, and pyrene yield electrical...

462 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023116
2022259
2021125
2020145
2019201
2018213