123863-97-8Relevant academic research and scientific papers
Tunable fluorene-based dynamers through constitutional dynamic chemistry
Giuseppone, Nicolas,Fuks, Gad,Lehn, Jean-Marie
, p. 1723 - 1735 (2006)
Dynamic covalent imino-fluorene-based oligomers and polymers have been generated. They undergo constitutional recomposition under the effect of two parameters, acidity and ZnII metal ions. As a result, marked changes in physical properties take
New quaternary phosphonium salt as multi-site phase-transfer catalyst for various alkylation reactions
Ponmuthu, Kottala Vijaya,Kumaraguru, Duraimurugan,Arockiam, Jesin Beneto,Velu, Sadhasivam,Sepperumal, Murugesan,Ayyanar, Siva
, p. 8345 - 8358 (2016)
The present work describes the C-alkylation reactions of fluorene and curcumin catalyzed by a new phosphonium salt, benzene-1,3,5-triyltris(methylene))tris(triphenylphosphonium)bromide, as a multi-site phase-transfer catalyst (MPTC). The catalytic efficie
Microwave-assisted FeCl3-mediated rapid synthesis of poly(9,9-dihexylfluorene) with high molecular weight
Zhang, Wensi,Wang, Zhiming,Zhang, Yunan,Lu, Ping,Liu, Linlin,Ma, Yuguang
, p. 5346 - 5349 (2014)
Poly(9,9-dihexylfluorene) with high molecular weight (Mw ～ 81,000) is obtained in 25 min using a microwave-assisted FeCl3-mediated oxidative polymerization. The effects of microwave power, time, solvent, monomer and catalyst's concentration on the polymerization have been systematically investigated. The structures and thermal properties of obtained polymers are fully characterized using FTIR, NMR, TGA, DSC, UV-visible absorption and fluorescence spectra. The results show that well-defined polymers have been obtained. XPS, ICP and elemental analysis are used to check the residue of iron catalyst, and almost no residue of FeCl3 is detected in polymers.
Synthesis and characterization of novel monodisperse starburst oligo(fluoreneethynylene) based on truxene moiety
Chen, Qing-Quan,Liu, Feng,Ma, Zhun,Peng, Bo,Wei, Wei,Huang, Wei
, p. 178 - 179 (2008)
A series of novel monodisperse star-shaped oligo(fluoreneethynylene)s, which contain hexahexyltruxene as the central core linked with oligo(fluoreneethynylene) as the arms, are presented. Copyright
Facile C?H alkylation in water: Enabling defect-free materials for optoelectronic devices
Saikia, Gunin,Iyer, Parameswar K.
, p. 2714 - 2717 (2010)
A facile method for the alkylation of fluorene achieved via direct C?H alkylation under aqueous conditions is reported, wherein the formation of fluorenone is inhibited, resulting in the exclusive formation of the desired dialkyl-substituted fluorene monomer. As a proof of concept, this method has also been successfully extended to perform N-alkylation of carbazole, diphenylamine, and N,N-dialkylation of aniline in high yields.
Crystalline 2D Covalent Organic Framework Membranes for High-Flux Organic Solvent Nanofiltration
Shinde, Digambar B.,Sheng, Guan,Li, Xiang,Ostwal, Mayur,Emwas, Abdul-Hamid,Huang, Kuo-Wei,Lai, Zhiping
, p. 14342 - 14349 (2018)
Two-dimensional (2D) covalent organic framework (COF) materials have the most suitable microstructure for membrane applications in order to achieve both high flux and high selectivity. Here, we report the synthesis of a crystalline TFP-DHF 2D COF membrane constructed from two precursors of 1,3,5-triformylphloroglucinol (TFP) and 9,9-dihexylfluorene-2,7-diamine (DHF) through the Langmuir-Blodgett (LB) method, for the first timed. A single COF layer is precisely four unit cells thick and can be transferred to different support surfaces layer by layer. The TFP-DHF 2D COF membrane supported on an anodic aluminum oxide (AAO) porous support displayed remarkable permeabilities for both polar and nonpolar organic solvents, which were approximately 100 times higher than that of the amorphous membranes prepared by the same procedure and similar to that for the best of the reported polymer membranes. The transport mechanism through the TFP-DHF 2D COF membrane was found to be a viscous flow coupled with a strong slip boundary enhancement, which was also different from those of the amorphous polymer membranes. The membrane exhibited a steep molecular sieving with a molecular weight retention onset (MWRO) of approximately 600 Da and a molecular weight cutoff (MWCO) of approximately 900 Da. The substantial performance enhancement was attributed to the structural change from an amorphous structure to a well-defined ordered porous structure, which clearly demonstrated the high potential for the application of 2D COFs as the next generation of membrane materials.
Synthesis and energy-transfer properties of hydrogen-bonded oligofluorenes
Dudek, Stephen P.,Pouderoijen, Maarten,Abbel, Robert,Schenning, Albertus P. H. J.,Meijer
, p. 11763 - 11768 (2005)
A set of fluorene oligomers has been synthesized by stepwise palladium-catalyzed (Suzuki) couplings of fluorene monomers. Ureidopyrimidinones (UPy), functional groups that can dimerize via quadruple hydrogen bonds, were attached to both ends of the oligof
Synthesis and characterization of new blue light emitting poly(arylenevinylene) derivatives containing fluorene pendant
Kim, Yun-Hi,Jung, Sang-Yun,Kwon, Soon-Ki
, p. 169 - 176 (2006)
New poly(arylenevinylene) derivatives composed of biphenyl or terphenyl units in the main chain and fluorene pendant groups are synthesized by Yamamoto coupling reaction or Suzuki coupling reaction. The obtained polymers showed high color pure blue emission due to controlled conjugation length and inhibited intermolecular interaction as well as high solubility and good thermal stability.
Understanding the reversible anodic behaviour and fluorescence properties of fluorenylazomethines A structure-property study
Barik, Satyananda,Friedland, Sayuri,Skene
, p. 945 - 953 (2010)
A series of fluorenylazomethine dyads and triads were prepared by simple condensation between the corresponding amine and aldehyde fluorene derivatives. These compounds were prepared as model compounds for investigating the effects of substitution and electronic groups on both the electrochemical properties and fluorescence quantum yields. It was found that the oxidation potential could be decreased by both incorporating electron donating groups and increasing the degree of conjugation. It was further found that alkylation in the fluorene's 9-position increased the azomethine degree of conjugation by forcing all the fluorene moieties to be coplanar with the azomethine bonds to which they are attached. Meanwhile, reversible radical cation behaviour was possible by substituting the terminal 2,2′-positions with atoms other than hydrogen. The radical cation was theoretically found to be distributed evenly across the fluorene, corroborating the reversible anodic behaviour with 2,2′-substitution. The fluorescence quantum yields of the azomethines were not found to be dependent on substitution. This was because the azomethine fluorescence was found to be quenched relative to their precursors regardless of substitution. The fluorescence could be restored at both low temperature and by acid protonation.
Photolumineseenee wavelength control of fluorene derivatives through h-bonding and protonation
Kawatsuki, Nobuhiro,Minami, Yuta,Lee, Joenghwan
, p. 298 - 299 (2009)
A fluorene monomer, which comprised 4-pyridylcyanovinyl groups (FL-CNPy), was synthesized, and the photolumineseenee (PL) properties of FL-CNPy combined with various (di)acids were evaluated. Due to hydrogen (H)-bonding or protonation between the pyridine end groups and acids, the PL emission maxima varied from 460 to 557 nm according to the acidity (pKa) and type of (di)acid. Additionally, adjusting the ratio of FL-CNPy/(di)acid tuned the PL emission wavelength without modifying the materials. Copyright
