1133-80-8Relevant articles and documents
Bromine-Substituted Fluorene: Molecular Structure, Br–Br Interactions, Room-Temperature Phosphorescence, and Tricolor Triboluminescence
Wang, Jiaqiang,Wang, Can,Gong, Yanbin,Liao, Qiuyan,Han, Mengmeng,Jiang, Tianjiao,Dang, Qianxi,Li, Yaqin,Li, Qianqian,Li, Zhen
, p. 16821 - 16826 (2018)
Organic tribophosphorescence materials are rarely reported and the introduction of Br atoms may be a practical way to design such materials. Here four bromine-substituted fluorene-based derivatives are presented and BrFlu?CBr, having fluorescence-phosphorescence dual-emission induced not only by UV light but also by mechanical stimulus, manifests the highest phosphorescence efficiency of 4.56 % upon photoirradiation. During the grinding process, three different triboluminescent spectra were identified. Upon introduction of a mechanical stimulus, the triboluminescence emission is cyan, whereas after an extended period it changed to blue. After removing the mechanical stimulus, green-white phosphorescent emission was observed. Careful research on single-crystal structures and theoretical calculations demonstrate that strong Br???Br interactions are vital to facilitate spin-orbit coupling and promote intersystem crossing, thus generating the unique properties.
Benzobisoxazole cruciforms: A tunable, cross-conjugated platform for the generation of deep blue OLED materials
Chavez, Ramiro,Cai, Min,Tlach, Brian,Wheeler, David L.,Kaudal, Rajiv,Tsyrenova, Ayuna,Tomlinson, Aimée L.,Shinar, Ruth,Shinar, Joseph,Jeffries-El, Malika
, p. 3765 - 3773 (2016)
Four new cross-conjugated small molecules based on a central benzo[1,2-d:4,5-d′]bisoxazole moiety possessing semi-independently tunable HOMO and LUMO levels were synthesized and the properties of these materials were evaluated experimentally and theoretically. The molecules were thermally stable with 5% weight loss occurring well above 350 °C. The cruciforms all exhibited blue emission in solution ranging from 433-450 nm. Host-guest OLEDs fabricated from various concentrations of these materials using the small molecule host 4,4′-bis(9-carbazolyl)-biphenyl (CBP) exhibited deep blue-emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.15 ≤ x ≤ 0.17, 0.05 ≤ y ≤ 0.11), and maximum luminance efficiencies as high as ~2 cd A-1. These results demonstrate the potential of benzobisoxazole cruciforms as emitters for developing high-performance deep blue OLEDs.
Synthesis and fluorescent properties of conjugated copolymers containing maleimide and fluorene units at the main chain
Nakamura, Munetoshi,Yamabuki, Kazuhiro,Oishi, Tsutomu,Onimura, Kenjiro
, p. 4945 - 4956 (2013)
Yamamoto or Suzuki-Miyaura coupling polymerizations of 2,3-diiodo-N- cyclohexylmaleimide with fluorene derivatives (2,7-dibromo-9,9′- dihexylfluorene and 9,9′-dihexylfluorene-2,7-diboronic acid) were carried out. The number-average molecular weights (Mn) of the resulting copolymers were 2600-3500 by gel permeation chromatography analysis. The fluorescence emission of the alternating copolymer showed the emission maxima at 551 nm in THF. On the other hand, the random copolymers showed the bimodal emission peaks at 418-420 and 555-557 nm region, respectively. The fluorescence peaks of the random copolymers on the long wavelength region (555-557 nm) were attributed to the conjugated neighboring N-cyclohexylmaleimide-9,9′- dihexylfluorene units in the polymer main chain. Furthermore, the copolymers exhibited the fluorescence solvatochromism by the difference of the polarity of solvents. The alternating and random copolymers showed the different fluorescence solvatochromism, and the emission colors are distinguishable by the naked eye, respectively. Copyright
Electropolymerized AIE-active polymer film with high quantum efficiency and its application in OLED
Li, Jinyu,Han, Xiao,Bai, Qing,Shan, Tong,Lu, Ping,Ma, Yuguang
, p. 707 - 715 (2017)
A carbazole functionalized electro-active AIE-activity molecule, TPE-DFCz, was designed, synthesized, and well characterized. The clear difference in oxidation potentials between tetraphenylethylene (TPE) unit and carbazole groups was found which guaranteed that polymerization occurred only at the peripheral carbazole groups and the TPE unit remained unchanged. Its luminescent network film was prepared conveniently by electrochemical polymerization (EP). The cross-linked film exhibited green emission with high quantum efficiency of 63%, relatively smooth surface, and good thermal stability. The effect of different scan cycles on the optical property was also investigated. The electroluminescent device using the optimized polymer film as active layer showed a maximum luminance of 3200 cd?m?2 and a maximum luminance efficiency of 1.16 cd?A?1 with very low roll-off of the efficiency. The AIE-active EP films afford more opportunities to develop polymer films with high quantum efficiency via a simple, effective method and promote the potential applications in display devices.
A novel amorphous oligo(phenylenevinylene) dimer with a biphenyl linkage center and fluorene end groups for electroluminescent devices
He, Feng,Xia, Hong,Tang, Shi,Duan, Yu,Zeng, Ming,Liu, Linlin,Li, Mao,Zhang, Haiquan,Yang, Bing,Ma, Yuguang,Liu, Shiyong,Shen, Jiacong
, p. 2735 - 2740 (2004)
A new type of oligo(phenylenevinylene) dimer, 2,5,2,5- tetra(9,9-dihexylfluorenyl)biphenyl (TFB), with a biphenyl linkage center and four fluorene end groups, has been synthesized by the Wittig reaction. The full characterization of its structure and optical properties, as well as the performance of its electroluminescent devices are presented. TFB shows strong blue fluorescence both in solution and as a solid film. High-quality films of TFB for light-emitting devices (LEDs) can be fabricated both by vacuum evaporation and the spin-coating technique, which is very special and interesting. Single-layer and multi-layer light-emitting devices using TFB as the active layer all show efficient blue emission.
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Tsuno,Y. et al.
, p. 601 - 607 (1978)
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Ligand Engineering for the Efficient Dye-Sensitized Solar Cells with Ruthenium Sensitizers and Cobalt Electrolytes
Aghazada, Sadig,Gao, Peng,Yella, Aswani,Marotta, Gabriele,Moehl, Thomas,Teuscher, Jo?l,Moser, Jacques-E.,De Angelis, Filippo,Gr?tzel, Michael,Nazeeruddin, Mohammad Khaja
, p. 6653 - 6659 (2016)
Over the past 20 years, ruthenium(II)-based dyes have played a pivotal role in turning dye-sensitized solar cells (DSCs) into a mature technology for the third generation of photovoltaics. However, the classic I3-/I- redox couple limits the performance and application of this technique. Simply replacing the iodine-based redox couple by new types like cobalt(3+/2+) complexes was not successful because of the poor compatibility between the ruthenium(II) sensitizer and the cobalt redox species. To address this problem and achieve higher power conversion efficiencies (PCEs), we introduce here six new cyclometalated ruthenium(II)-based dyes developed through ligand engineering. We tested DSCs employing these ruthenium(II) complexes and achieved PCEs of up to 9.4% using cobalt(3+/2+)-based electrolytes, which is the record efficiency to date featuring a ruthenium-based dye. In view of the complicated liquid DSC system, the disagreement found between different characterizations enlightens us about the importance of the sensitizer loading on TiO2, which is a subtle but equally important factor in the electronic properties of the sensitizers.
Conjugated diene monomer 9-9 - dialkyl fluorene as structural unit and synthesis method thereof
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Paragraph 0042; 0045-0049, (2021/10/05)
The invention relates to a conjugated diene monomer 9-9 - dialkyl fluorene as a structural unit and a synthesis method thereof, and belongs to the technical field of organic synthesis. 9, 9 - Dialkyl fluorene is the structural unit of the conjugated diene monomer. Herein R is a linear or branched alkyl group having a different number (6 - 30) of carbon atoms, n Shows functional groups of each intermediate, and a functional ethylenic monomer with Suzuki and 9 dialkyl fluorene as a core with different conjugation lengths can be obtained by repeating the bromination and acetylation reduction of the fluorene or 9 - fluorene oligomer. The problem of flexible expansion of chemical reaction of organic small molecules of fluorene units can be solved.
Bipolar micromolecule luminescent material processed by using environment-friendly solvent as nucleus and preparation method and application thereof
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Paragraph 0038-0041, (2020/05/08)
The invention discloses a bipolar small molecular luminescent material capable of being processed by adopting an environment-friendly solvent and taking a naphtho-indenofluorene unit as a core as well as a production method and application of the bipolar small molecular luminescent material. The production method comprises the following steps: by taking the naphtho-indenofluorene unit containing a polar substituent group as the core; carrying out a Suzuki coupling reaction, and connecting an electron donor unit and an electron withdrawing unit onto two sides of the naphtho-indenofluorene unit in sequence, so as to obtain the bipolar small molecular luminescent material taking the naphtho-indenofluorene unit as the core. The bipolar small molecular luminescent material taking the naphtho-indenofluorene unit as the core, disclosed by the invention, has good solubility, film forming property and thin film form stability in the environment-friendly solvent; a luminescent layer produced by the luminescent material can avoid a mixing phenomenon with a hole/electron transmission layer interface; the prepared luminescent layer does not need to be subjected to annealing treatment when being used for preparing a luminescent device, so that a preparation process is simple.