• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.430-435
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• 2011

Coal fly ash of thermal power plants converted into mesoporous materials MCM-41. The synthesized material was characterized by XRD, FT-IR, SEM, and EDS techniques. The catalytic activity of prepared material was studied for the synthesis of 5-arylindene malononitriles via Knoevenagel condensation of aromatic aldehydes and malonontrile is described. The features of present method are easy handling, stability, reusability, and eco-friendliness of catalyst, high yields, short reaction time, simple experimental and work up procedure.

• Journal of the Korean Chemical Society
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• v.52 no.5
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• pp.593-596
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• 2008

• Journal of the Korean Chemical Society
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• v.51 no.4
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• pp.346-351
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• 2007

Efficient stereoselective synthesis of α,β-Unsaturated acids, α-Cyanoacrylonitriles and α-Cyanoacrylates has been carried out in the presence of NaHSO4·SiO2 under solvent?free conditions with an E-geometry.

• Korean Chemical Engineering Research
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• v.44 no.4
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• pp.417-423
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• 2006

A series of amine functionalized MCM-41 catalysts were prepared by aminopropyltrimethoxysilane grafting and their catalytic performance in Knoevenagel reaction of selected substrates was investigated. Water resistant and catalytically active amine grafted MCM-41 was prepared by post-synthetic silylation using methyltrimethoxysilane ; hydrogen bonding of the water molecules formed during the condensation reaction to the active N group was suppressed, which led to high TON of the reaction. Amine functionalized MCM-41 prepared by coating method produced high conversion, but the TON of the catalyst was much lower than that of the amine grafted MCM-41; pore volume of the functionalized MCM-41 decreased substantially and large portion of the immobilized amine is believed to be hydrogen bonded to each other, which can result in decrease in the basicity of the N group. A secondary amine group was prepared by room temperature condensation between aminopropylsilane and chloropropylsilane, and the MCM-41 grafted with the secondary amine group demonstrated the highest catalytic activity among the catalysts prepared.

• Journal of the Korean Chemical Society
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• v.49 no.4
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• pp.377-380
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• 2005

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.609-613
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• 2006

4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) derivatives were synthesized by Knoevenagel condensation. They are red-emitting materials for OLED (Organic Light-Emitting Diode) composed of electron donor of aminostyryl groups and electron acceptor of two cyano(nitrile)groups in a conjugated structure. The structural properties of reaction products were analyzed by FT-IR and $^1H-NMR$ spectroscopy. The thermal stabilities and reactivities were measured by melting points and yields. The UV-visible and PL properties can be determined by exitation and emission spectra, respectively.

• Applied Chemistry for Engineering
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• v.20 no.1
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• pp.40-45
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• 2009

N-Alkylcarbazole-3-vinylene-2-methyl-4-dicyanomethylene-4H-pyran derivatives were synthesized by dehydration, $S_N2$, Vilsmeier, and Knoevenagel condensation. They are red-emitting materials for organic light emitting device (OLED) composed of electron donor of N-alkylcabazole-3-vinylene groups and electron acceptor of 2-methyl-4-dicyanomethylene-4H-pyran groups by a conjugated structure. The structural properties of reaction products were analyzed FT-IR and $^1H-NMR$ spectroscopy. The thermal stabilities and reactivities were measured by melting points and yields. The UV-visibles and PL properties can be determined by exitation spectra and emission spectra, respectively.

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.587-591
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• 2007

6-(10-Alkylphenothiazine-3-vinylene)-2-methyl-4-dicyanomethylene-4H-pyran derivatives were synthesized by Knoevenagel condensation. They are red-emitting materials for organic light emitting device (OLED) which composed of electron donor of 6-(10-Alkylphenothiazine-3-vinylene) groups and electron acceptor of -2-methyl-4-dicyanomethylene-4H-pyran groups by a conjugated structure. The structural properties of reaction products were analyzed FT-IR and $^1H-NMR$ spectroscopy. The thermal stabilities and reactivities were measured by melting points and yields. The UV-visibles and PL properties can be determined by exitation spectra and emission spectra, respectively.

• Polymer(Korea)
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• v.32 no.1
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• pp.56-62
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• 2008

Three types of network polyesters have been newly synthesized by a two-step condensation reaction by the various combination of several diols and diacids. When these polymer films were thermally treated at $240^{\circ}C$, they exhibited absorptions in a visible range despite the forbidden transition of carbonyl group. When excited at wavelengths above 330 nm, the polymers showed fluorescences in a wide visible range from blue to near yellow. These fluorescence phenomena are due to the formation of certain conjugated structures by the Knoevenagel type self-condensation under the high-temperature thermal treatment. These polymers showed significant difference in the thermal properties as a function of the degrees of chemical crosslinking. They also underwent photodegradation. Highly resolved, fluorescent image patterns were successfully obtained by the photodegradation of malonate group under a strong UV-light irradiation.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.348-352
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• 2011

In this research, we have synthesized new pendant-type polyurethane polymers by introducing various chromophores with stilbene derivatives in the side-chain of the polymer backbone. The Stilbene monomers, N,N-bis(2-hydroxyethyl) amino-4'-cyanostilbene, N,N-bis(2-hydroxyethyl)amino-4'-methoxy stilbene, N,N-bis(2-hydroxyethyl)amino-4'-acetylstilbene, and N,N-bis(2-hydroxyethyl) amino stilbene, were synthesized by Wittig reaction. Another stilbene monomer, N,N-bis(2-hydroxyethyl)amino-4'-nitrostilbene, was synthesized by Knoevenagel condensation. By the measurement of UV-Vis absorption and Photoluminescence (PL) spectrum, we found that introduction of the electron-withdrawing group as a substituent shifts both UV-Vis and PL spectra to longer wavelength, and the introduction of the electron-donating group results in blue-shift of the spectrum. In case of polymer with $NO_2$ group as a substituent, PL is quenched.