• Journal of the Korean Chemical Society
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• v.38 no.4
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• pp.295-301
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• 1994

The Ru(Ⅲ), Ni(Ⅱ), Cu(Ⅱ), and Pd(Ⅱ) complexes of N$_4$-polydentate ligands(meso-Me$_6$-[14]-ane, rac-Me$_6$-[14]-ane, and cyclam) have been prepared and their catalytic activity and selectivity in the oxidation of olefins in the presence of oxidant such as NaOCl, H$_2$O$_2$, t-BuOOH, and PhIO studied. The oxidations of cyclohexene, 1-hexene, cyclooctene, 1-octene, and styrene as substrates have been investigated gas chromatographically. The Ru(Ⅲ)-N$_4$ complexes showed high selectivity for epoxide in the catalyzed oxidation of olefins with NaOCl. The catalytic activities of Ru(Ⅲ)-N$_4$ complexes were discussed in terms of the flexibility of N$_4$-polydentate ligands, the Ru(Ⅲ)-Cl bond interaction and the steric effect of oxidants. The oxidation of 1-octene using PhIO as oxidant was carried out to verify. The Pd(Ⅱ) complex turned out to be more active catalyst than the Ni(Ⅱ) complexes.

• Membrane Journal
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• v.24 no.1
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• pp.1-9
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• 2014

In this study, four soluble homo- and co-polyimides using 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (DOCDA) and 4,4'-diaminodiphenyl ether (ODA) monomers were synthesized to develop the gas separation membrane with good $CO_2/CH_4$ separation properties. To prepare the copolyimides, 20 mol% of three dianhydrides - (4,4'-(hexafluoroisoproplidene)diphthalic anhydride (6FDA), 4,4'-biphthalic anhydride (BPDA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) - were added in DOCDA-ODA monomer mixture, respectively. All the synthesized homo- and co-polyimides were characterized by FT-IR. Their thermal properties were analyzed with differential scanning calorimeter (DSC). Dense membranes were prepared from these copolyimides to check their gas permeation properties for $CO_2$ and $CH_4$ gases using a time-lag method. The permeation testing results are as follows; DOCDA/ODA homopolymer showed 1.71 barrer of $CO_2$ permeability and 74.35 of $CO_2/CH_4$ selectivity. The three polyimide copolymers (DOCDA/6FDA-ODA, DOCDA/BPDA-ODA, DOCDA/BTDA-ODA) showed lower $CO_2/CH_4$ selectivities and higher $CO_2$ permeabilities than the homopolymer (DOCDA-ODA). DOCDA/6FDA-ODA showed twice times higher $CO_2$ permeabilities without severe $CO_2/CH_4$ selectivity loss than the DOCDA-ODA.

• Membrane Journal
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• v.25 no.3
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• pp.231-238
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• 2015

Co-polyimide membranes were prepared by two-step polymerization using semi-alicyclic 5-(2,5-dioxotetrahydrofuryl)-3-methyl-cyclohexene-1,2-dicarboxylic anhydride (DOCDA) with five diamines such as 2,5-dimethyl-1,4-phenylene diamine (2M), 2,4,6-trimethyl-1,3-phenylene diamine (3M), 1,5-naphthalene diamine (NDA), 4,4-diaminodiphenyl methane (MDA), 4,4'-diaminodiphenyl ether (ODA). Synthesized co-polyimides were characterized by FT-IR, viscosity, solubility, DSC, TGA and gas permeation properties, compared with 6FDA-based co-polyimides. All co-polyimides had the intrinsic viscosity of 0.32~0.58 and excellent solubility in various solvents. DOCDA-based co-polyimides had thermal stability over $400^{\circ}C$ although those were lower than 6FDA-based co-polyimides. Gas permeabilities of the copolyimide membranes were measured for $CO_2$ and $CH_4$ at room temperature and presented the trade-off relationship.

• Weed & Turfgrass Science
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• v.1 no.4
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• pp.44-49
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• 2012

The objective of this study was to know the herbicidal activity of the essential oil from amyris (Amyris balsamifera). In a seed bioassay experiment, the amyris essential oil inhibited the growth of rapeseed (Brassica napus) by fifty percent at 8.8 ${\mu}g\;g^{-1}$. And in a greenhouse experiment, sorghum, barnyard grass and Indian jointvetch, which was applied in above-ground parts, with the amyris essential oil at 4,000 ${\mu}g\;ml^{-1}$ showed visual injuries of 90, 70, and 70, respectively (0, no damage; 100, total damage). However, soil application of the essential oil did not show such herbicidal injuries. In a field experiment, foliar application of the amyris essential oil at 5% controlled effectively weeds such as barnyardgrass, shepherd's purse, and clover in 24 hours. Our results indicated that the amyris essential oil had herbicidal activity. To understand the composition of the amyris essential oil, the oil was analyzed by gas chromatography-mass spectometry with solid-phase micro-extraction apparatus. There were 15 organic chemicals in the oil and the major constituents were calarene, elemol, ${\gamma}$-eudesmol, curcumene, ${\beta}$-sesquiphellandrene, zingiberene, selina-3,7(11)-diene, 1,3-diisopropenyl-6-methyl-cyclohexene, ${\beta}$-bisabolene, and ${\beta}$-maaliene. Overall results suggest that the amyris essential oil had a herbicidal activity with fast, contact, and non-selective mechanism.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.820-823
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• 2002

The diethylet er fraction from the leaves extract of Ligularia fischeri var. spiciformis (Compositae) was subjected to silica gel column chromatography and yielded three new terpenoids named spiciformisin a (1), spiciformisin b (3), and monocyclosqualene (2). Acyclic diterpenes, spiciformisin a and -b, were established as 3,7,11,15-tetramethyl-1,3(20)-hexadecadiene and 3,7,11,15-tetramethyl-1,3,6,10,14-hexadecapentaene (IUPAC), respectively. A monocyclic triterpene, monocyclosqualene, were determined as [3,8,12,16,16-pentamethyl-(3,7,11,15-hexadecatetraenyl)]-3,3,5-trimethyl-1-cyclohexene. The structures were determined on the basis of NMR and MS analysis. Spiciformicin b showed potent cytotoxicity ($IC_{50},{\;}<9.7{;\}{\mu\textrm{g}}/ml$ against HL-60) in contrast to no cytotoxicity ($IC_{50},{\;}>200{\;}}{\mu\textrm{g}}/ml against HL-60 cells) of spiciformicin a with a cis-conjugated dienyl diexomethylene.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.930-940
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• 2012

A comparison of essential oils composition of Aster tataricus L. (gaemichwi), Ligularia fischeri (gomchwi), Solidago virga-aurea var. asiatica Nakai (miyeokchwi), and Aster scaber (chamchwi) was performed by gas chromatography and mass spectrometry for the identification of volatile flavor characteristics in chwi-namuls. The essential oils were extracted by the hydro distillation extraction method. One hundred volatile flavor components were identified from gaemichwi essential oil. ${\alpha}$-Pinene (11.5%) was the most abundant compound, followed by myrcene (8.9%) and ${\beta}$-pinene (7.5%). Ninety-one volatile flavor components were identified from the essential oil of gomchwi. Aromadendrene (14.8%) was the most abundant component, followed by ${\beta}$-caryophyllene (7.6%) and 1-methyl-4-(1-methylethylidene)-cyclohexene (7.3%). Ninety-five volatile flavor constituents were detected in the essential oil of miyeokchwi, moreover, spathulenol (15.7%) was the most abundant component. Ninety-six volatile flavor constituents were detected in the essential oil of chamchwi. Epi-bicyclosesquiphellandrene (21.9%) was the most abundant component, followed by ${\beta}$-caryophyllene (9.5%) and ${\delta}$-terpinene (8.9%). The essential oil composition of gaemichwi was characterized by a higher contents of pinenes. The essential oil composition of gomchwi can be easily distinguished by the percentage of aromadendrene. Spathulenol and epi-bicyclosesquiphellandrene were regarded as the characteristic odorants of miyeokchwi and chamchwi, respectively.

• Journal of Adhesion and Interface
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• v.7 no.4
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• pp.39-44
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• 2006

A new kind of silicone-epoxy composite is reported in this research. The silicone-epoxy resin was synthesized by the hydrosilylation of tetramethycyclotetrasiloxane and 4-vinyl-1-cyclohexene 1,2-epoxy with a high reaction yield. It was found that the obtained silicone-epoxy resin shows a high reactive activity to the aluminum complex-silanol catalyst. The resin could be cured under the catalysis of $(Al(acac)_3/Ph_2Si(OH)_2$ at a concentration below 0.1 wt% to give a hard cured resin showing excellent optical clarity, UV resistance and thermal stability. It was also found that the Si-H groups facilitated the curing reaction and the silicone-epoxy resin bearing Si-H group could be cured effectively even if $Ph_2Si(OH)_2h$ was absent. Moreover, the UV resistance and thermal stability were improved significantly by the introduction of Si-H groups. This is possibly due to the reductive property of Si-H groups which can annihilate radical and peroxide effectively. This kind of silicone-containing epoxy composite might have very promising applications as optical resin, optical adhesive and encapsulation materials for electronic devices.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.563-568
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• 2005

The Pt/C and Pd/C catalysts were prepared from conventional chloride precursors by adsorption or precipitation-deposition methods. Their activities for hydrogenation reactions of cyclohexene and acetophenone were compared with those of commercial catalysts. The Pt/C and Pd/C catalysts obtained from the adsorption procedure reveal higher hydrogenation activity than commercial catalysts and the catalysts prepared by the precipitation-deposition method. Their improved performances are attributed to the decreased metal crystallite sizes of Pt or Pd formed on the active carbon support upon the adsorption of the precursors probably due to the same negative charges of the chloride precursor and the carbon support. Under the preparation conditions studied, the reduction of the supported catalysts using borohydrides in liquid phase is superior to a gas phase reduction by using hydrogen in the viewpoint of particle size, hydrogenation activity and convenience.

• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.609-614
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• 2008

A periodic mesoporous organosilica material was synthesized by microwave heating (PMO-M) using 1,2-bis(trimethoxysilyl)ethane as a precursor in a cationic surfactant solution, and textural properties were compared with those of the product produced by conventional convection heating (PMO-C). These synthesized materials were characterized using XRD, TEM/SEM, N2 adsorption isotherm, 29Si and 13C NMR, and TGA, which confirmed their good structural orders and clear arrangements of uniform 3D-channels. Synthesis time was reduced from 21 h in PMO-C to 2-4 h in PMO-M. PMO-M was made of spherical particles of 1.5-2.2 m m size, whereas PMO-C was made of decaoctahedron-shaped particles of ca. 8.0 m m size. Effect of synthesis temperature, time, and heating mode on the PMO particle morphology was examined. The particle size of PMO-M could be controlled by changing the heating rate by adjusting microwave power level. PMO-M demonstrated improved separation of selected organic compounds compared to PMO-C in a reversed phase HPLC experiment. Ti-grafted PMO-M also resulted in higher conversion in liquid phase cyclohexene epoxidation than by Ti-PMO-C.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.2
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• pp.85-94
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• 2009

This work has been conducted to develop a method for the analysis of neutral volatile flavors and their precursors in tobacco. The neutral volatile compounds and precursors in tobaccos have been investigated by Neutral Volatile scan method(NV scan) using Soxhlet extractor. The method has been used to analyze a range of different tobaccos and tobacco products. Neutral flavor compounds were classified as three sections(1st Volatile Fraction, Breakdown Flavor Products and Cembranoid Precursors). The major components of the First Volatile Fraction were 2-cyclohexene-1-one, 6-methyl-5-hepten-2-one, limonene and phenyl ethanol. The major components of Breakdown Flavor Products were isophorone, solanone, damascenone, 3-hydroxy-$\beta$-damascone, geranyl acetone, $\beta$-ionone, dihydroactinidiolide, norsolanadione, neophytadiene, hexahydrofarnesylacetone, farnesyl acetone and megastigmatrienone. The major cembranoid precursor compounds were dibutyl phthalate, duvatrenediols, 8,12-epoxy-14-labden-13-ol, 11-hydroperoxy-2,7,12(20)-cembratriene-4,6-diol, 12,15-epoxy-12,14-labadien-8-ol, 2,7,11-cembratrien-4,6-diol and 8,13-epoxy-14-labdien-12-ol. The NV scna results of tobacco types(flue-cured, burley and oriental) showed that each tobacco type has a characteristic flavor component profile.