58775-05-6Relevant academic research and scientific papers
Site selectivity of [RuCp]+ complexation in cyclopenta[ def ]triphenylenes
Hoggard, Bryce R.,Larsen, Christopher B.,Lucas, Nigel T.
, p. 6200 - 6209 (2014)
A series of new cyclopenta-fused triphenylenes has been synthesized in high yield and reacted with [Ru(μ3-Cl)Cp]4 to form [RuCp(η6-arene)]PF6 complexes. Systematic variation of the cyclopenta[def]triphenylene al
The Role of Torsional Dynamics on Hole and Exciton Stabilization in π-Stacked Assemblies: Design of Rigid Torsionomers of a Cofacial Bifluorene
Wang, Denan,Ivanov, Maxim V.,Kokkin, Damian,Loman, John,Cai, Jin-Zhe,Reid, Scott A.,Rathore, Rajendra
, p. 8189 - 8193 (2018)
Exciton and charge delocalization across π-stacked assemblies is of importance in biological systems and functional polymeric materials. To examine the requirements for exciton and hole stabilization, cofacial bifluorene (F2) torsionomers were designed, synthesized, and characterized: unhindered (model) MeF2, sterically hindered tBuF2, and cyclophane-like CF2, where fluorenes are locked in a perfect sandwich orientation via two methylene linkers. This set of bichromophores with varied torsional rigidity and orbital overlap shows that exciton stabilization requires a perfect sandwich-like arrangement, as seen by strong excimeric-like emission only in CF2 and MeF2. In contrast, hole delocalization is less geometrically restrictive and occurs even in sterically hindered tBuF2, as judged by 160 mV hole stabilization and a near-IR band in the spectrum of its cation radical. These findings underscore the diverse requirements for charge and energy delocalization across π-stacked assemblies.
Preparation of high purity 4-bromofluorenone method of
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Paragraph 0021; 0025; 0026, (2016/10/17)
The invention relates to a novel method for preparing high-purity 4-bromofluorene. The novel method comprises the following steps: by taking dichloroethane as a solvent and aluminum trichloride as a catalyst, enabling fluorene and 2-chloro-2-methylpropane to be in Friedel-Crafts reaction to obtain a 2,7-di-tert-butyl fluorene crude product; carrying out bromination on the 2,7-di-tert-butyl fluorene crude product by virtue of a high-selectivity bromination reagent to obtain 2,7-di-tert-butyl-4-bromofluorene; removing tertiary butyl from the 2,7-di-tert-butyl-4-bromofluorene by virtue of lewis acid to obtain 4-bromofluorene; re-crystallizing with alcohol at a reaction temperature of 10 DEG C-50 DEG C to obtain 4-bromofluorene. The 4-bromofluorene prepared by the method is high in purity and has GC purity of 99.9%, dibromofluorene content less than 100ppm and good application prospect.
C-9 fluorenyl substituted anthracenes: A promising new family of blue luminescent materials
Wang, Jing,Wan, Wen,Jiang, Haizhen,Gao, Yan,Jiang, Xueyin,Lin, Huaping,Zhao, Weiming,Hao, Jian
supporting information; experimental part, p. 3874 - 3877 (2010/11/18)
Syntheses, optical, and electrochemical properties of novel C-9 fluorenyl substituted anthracenes linked by a tetrahedral sp3-hybridized carbon atom are reported for blue light emitting materials. Remarkably, an unoptimized organic light-emitting diode based on 1-fold fluorene-functionalized anthracene 3 exhibits a radiance of 4100 cd/m2 at 12 V and a maximum EL efficiency of 1.36 cd/A with color purity CIE x, y (0.157, 0.082), which is very close to the National Television System Committee standard blue.
New dispiro compounds: Synthesis and properties
Portel, Cyril,Rault-Berthelot, Joelle,Barriere, Frederic,Slawin, Alexandra M. Z.
, p. 373 - 376 (2008/09/20)
We report the synthesis and structural characterization of two dispiro compounds. These two positional isomers have been designed and synthesized through an efficient method. Because of the rigidity and orthogonality of the spiro bridge, both molecules ex
Efficient method for the synthesis of hetarenoindanones based on 3-arylhetarenes and their conversion into hetarenoindenes
Kashulin, Igor A.,Nifant'ev, Ilya E.
, p. 5476 - 5479 (2007/10/03)
A series of hetarenoindanones have been prepared by direct double metalation of the appropriate 3-phenylhetarene with butyllithium in the presence of TMEDA followed by treatment of the resulting dilithium compound with ethyl N ,N-dimethylcarbamate. All hetarenoindanones were reduced according to Wolff-Kishner by hydrazine in the presence of KOH to the corresponding hetarenoindenes.
Fluorenylalkanoic and benzoic acids as novel inhibitors of cell adhesion processes in leukocytes
Hamilton,Mewshaw,Bryant,Feng,Endemann,Madden,Janczak,Perumattam,Stanton,Yang,Yin,Venkataramen,Liu
, p. 1650 - 1656 (2007/10/02)
A series of fluoren-9-ylalkanoic and alkylbenzoic acids was prepared as simplified analogues of a previously reported series of antiinflammatory agents which act to inhibit neutrophil recruitment into inflamed tissue. The previous compounds ('leumedins')
Investigation of the Reaction between Amino Acids or Amino Acid Esters and 9-Formylfluorene and Its Equivalents. Possible Utility of the Derived Enamines as Amino Group Protectants
Carpino, Louis A.,Chao, Hann Guang,Tien, Jien-Heh
, p. 4302 - 4313 (2007/10/02)
Treatment of 9-(hydroxymethylene)fluorene/9-formylfluorene (storable as the hemiacetal with methanol, 7) with amino acids and amino acid esters yields the corresponding enamines 8, which may be considered to be hydrocarbon analogues of N-formyl amino acid derivatives.Attempted coupling of the free acids 8 (R'=H) with amino acid esters failed, suggesting insufficient reduction in basicity of the amino group due to the enamine residue.The introduction of electron-withdrawing substituents into the fluorene ring decreases the basicity sufficiently to allow normal peptide coupling reactions, as for example with the 2,7-dichloro analogues derived from 17.Thus phenylalanine derivative 18 treated with leucine methyl ester and DCC gave dipeptide 19.The DC-FM-bar group could be removed by catalytic transfer hydrogenolysis.Mild acid hydrolysis represents a second general deblocking technique for the FM-bar function.It was demonstrated in a model study involving the highly sensitive amino acid α-phenylglycine that the FM-bar protecting group was less prone to cause racemization than the benzyloxycarbonyl function.It was demonstrated that the simple pentapeptide leucine enkephalin 29 could be synthesized using α-DC-FM-bar protection along with tert-butyl-based side chain protecting groups.
Selective Preparation of Fluorene Derivatives Using the t-Butyl Function as a Positional Protective Group
Kajigaeshi, Shoji,Kadowaki, Toshiya,Nishida, Akiko,Fujisaki, Shizuo
, p. 97 - 104 (2007/10/02)
Several 4-substituted 2,7-di-t-butylfluorene derivatives (3) were prepared by electrophilic substitutions of 2,7-di-t-butylfluorene (1). 4-Substituted fluorene (4), such as 4-bromo- (4a), 4-methyl (4e), and 4-aacetylaminofluorene (4j), were obtained by the trans-t-butylations of 3.Although we attempted to synthesize 1,8-disubstituted fluorene from 3,6-di-t-butylfluorene (2) which was derived from 2,2'-diiodo-4,4'-di-t-butyldiphenylmethane (5), by the same methods, we obtained only 2,7-disubstituted fluorene derivatives (8); it turned out electrophilic substitutions of 2 gave 2,7-disubstituted 3,6-di-t-butylfluorene derivatives.
