• Archives of Pharmacal Research
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• v.17 no.1
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• pp.17-20
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• 1994

Friedel-Crafts reaction of fluorene with methyl ${\alpha}$-chloro-${\alpha}$-(methylthio)acetate 1 gave methyl $\alpha$-methylthio-2-fluoreneacetate 2. Cicloprofen 8, a potent antiinflammatory agent, was prepared by methylation of 2 followed by reductive desulfurization of methyl 2(2-fluorenyl)-2-(methylthio)propionate 6 and hydrolysis of methyl 2-(2-fluorenyl)propionate 7.

• Membrane Journal
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• v.16 no.3
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• pp.221-229
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• 2006

This study is about the preparation and characterization of sulfonated random copolymer membranes containing perfluorocyclobutane (PFCB), fluorenyl, and sulfonyl units. The polymers were prepared through three synthetic steps, that is, the synthesis of a trofluorovinylether-terminated monomer, its thermal polymerization, and post-sulfonation using chlorosulfonic acid. A series of sulfonated random copolymers with different ion exchange capacity (IEC) were prepared by changing contents of fluorenyl uints in polymers with fixed molar ratio of chlorosulfonic acid during the post-sulfonation reaction. All the synthesized compounds were characterized by FT-lR, $^1H-NMR$, $^{19}F-NMR$, and Mass spectroscopy. As the content of sulfonated fluorenyl units increased, the IEC, water uptake, and ion conductivity of the sulfonated random copolymer membranes increased. The sulfonated random copolymer S-1 and S-2 showed higher values of ion conductivity than the Nafion-115 in a wide range of temperatures ($25{\sim}80^{\circ}C$).

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2141-2142
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• 2010

• Bulletin of the Korean Chemical Society
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• v.20 no.12
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• pp.1487-1492
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• 1999

The kinetics of oxidation of substituted styryl 4-biphenyl ketones and of substituted styryl 2-fluorenyl ketones by pyridinium chlorochromate (PCC) have been studied in 90% acetic acid- 10% water (v/v) containing perchloric acid and NaClO₄ at $10^0,\;20^0,\;30^0$ and 40℃. The reactions are first order in styryl ketones and PCC. The second order rate constants are well correlated only with σ$^+$ constants implying development of positive charge adjacent to benzene ring in the transition state. The effects of varying [HClO₄] and the percentage of acetic acid on the reactions have also been analysed. A mechanism involving nucleophilic attack of PCC leading to an unsymmetric intermediate from which epoxides are formed is proposed.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.239-239
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• 2006

In the present study, we synthesized CBDA-FDA and its analogue, poly(4,4' -(9,9-fluorenyl)diphenylene pyromellitimide) (PMDA-FDA), and then investigated quantitatively the orientational distributions of the polymer chain segments in the surfaces of their films by using linearly polarized Fourier transform infrared (FTIR) spectroscopy and optical retardation analysis. We also examined the films' surface topographies using high spatial resolution atomic force microscopy (AFM). Further, rubbed films were used to assemble antiparallel and $90^{\circ}-twisted$ nematic (TN) LC cells, and the alignment behaviors, pretilt angles and anchoring energies of the LC molecules in the cells were determined. The films were found to have very interesting surface morphologies and LC alignment behaviors, which have not previously been reported. The observed LC alignments, pretilt angles and anchoring energies are discussed by taking into account the interactions of the LC molecules with the oriented polymer chain segments and the surface morphologies.

• Macromolecular Research
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• v.12 no.3
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• pp.316-321
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• 2004

We have performed copolymerizations of ethylene with 1-hexene using various ansa-metallocene compounds in the presence of the non-coordinative [CPh$_3$][B(C$\_$6/F$\_$5/)$_4$ion pair as a cocatalyst. The metallocenes chosen for this study are isospecific metallocene diamide compounds, rac-(EBI)Zr(NMe$_2$)$_2$ [1, EBI = ethylene-l ,2-bis(1-indenyl)], rac-(EBI)Hf(NMe$_2$)$_2$ (2), rac-(EBI)Zr(NC$_4$H$\_$8/)$_2$ (3), and rac-(CH$_3$)$_3$Si(1-C$\_$5/H$_2$-2-CH$_3$-4-$\^$t/C$_4$H$\_$9/)2 Zr(NMe$_2$)$_2$ (4), and syndiospecific metallocene dimethyl compounds, ethylidene(cyclopentadienyl)(9-fluorenyl) ZrMe$_2$ [5, Et(Flu)(Cp )ZrMe$_2$] and isopropylidence (cyclopentadienyl)(9-fluorenyl)ZrMe$_2$ [6, iPr(Flu)(Cp)ZrMe$_2$]. The copolymerization rate decreased in the order 4 ＞1-3＞2 ＞5＞6. The reactivity of I -hexene decreased in the order 2 ＞6＞1- 3-5＞ 4. We characterized the microstructure of the resulting poly(ethylene-co-l-hexene) by $\^$l3/C NMR spectroscopy and investigated various other properties of the copolymers in detail.

• Clean Technology
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• v.16 no.4
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• pp.239-244
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• 2010

The carboxylation of the fluorenyl epoxide with a spiro framework, 9,9'-Bis(4-oxiranylmethoxyphenyl) fluorine (2) was catalyzed by some onium salts such as quaternary ammonium and phosphonium salts to produce the corresponding five-membered cyclic carbonate (3) in an efficient and environmentally benign fashion. The coupling reactions depend greatly on the kind of the halide anions and alkyl chain length of the onium salts. While the reaction was sensitive to the reaction temperature, the reaction trends suggest that the catalytic efficiency of the quaternary ammonium halides may correlate strongly with the melting points of the halides. The reactions using a catalytic amount (2 mol %) of quaternary ammonium bromide with an n-butyl chain at 75.9 bar of $CO_2$ and 393 K give the highest yield of the cyclic carbonate (92%).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1013-1015
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• 2002

1-(9,9-Di-octyl-fluorenyl)-2-substituted-2-cyanvinylene was synthesized and emission feature in solution are presented. Photoluminescence characteristics of 1-(9,9-Di-octyl-fluorenyJ)-2-substituted-2-cyanvinylene are measured by solvents such as carbon tetrachloride, normal hexane, chloroform, ethylaccetate, acetonitrile, methanol. It is shown that depending in the strength of the donor-acceptor internal charge transfer, and emission spectra are more or less red-shifted.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.1973-1979
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• 2007

Novel organic dyes, JK-34, JK-35 and JK-36 containing bis-dimethylfluorenyl amino coumarin unit are designed and synthesized. Nanocrystalline TiO2 dye-sensitized solar cells were fabricated using these dyes. Under standard global AM 1.5 solar condition, the JK-34 sensitized cell gave a short circuit photocurrent density of 10.05 mA cm?2, open circuit voltage of 0.65 V, and a fill factor of 0.68, corresponding to an overall conversion efficiency η of 4.54%. We found that the power conversion efficiency was shown to be quite sensitive to the structural modifications of bridging thiophene moiety.

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.183-186
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• 2005