• Title/Summary/Keyword: $CO_2$-Acetonitrile

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A Study on Phase Behavior of CO2-Acetonitrile and CO2-Acrylonitrile System at High Pressure (고압에서 CO2-아세토니트릴과 CO2-아크릴로니트릴계에 대한 상거동에 관한 연구)

  • Byun, Hun-Soo;Kim, Youn-Sop;Im, Jong-Kyun
    • Applied Chemistry for Engineering
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    • v.9 no.6
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    • pp.924-929
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    • 1998
  • In this work, high pressure binary phase equilibria data of carbon dioxide with acetonitrile and acrylonitrile were obtained experimentally. A new static type experimental apparatus was built to measure temperature, pressure and phase equilibria composition. The accuracy of the experimental apparatus was tested by comparing the measured phase equilibria data of the carbon dioxide-acetonitrile system at $75^{\circ}C$ with those of McHugh and coworkers. The binary phase behavior data of carbon dioxide-acetonitirle system were measured from 2.4 to 14.5 MPa at $55^{\circ}C$, $75^{\circ}C$ and $100^{\circ}C$. Also, the phase equilibria of the system carbon dioxide-acrylonitrile were measured from 1.6 MPa up to 13.9 MPa at $45^{\circ}C$, $65^{\circ}C$, $85^{\circ}C$ and $105^{\circ}C$. The solubility of acetonitrile and acrylonitrile increases as the temperatures increases at constant pressure. Also, these two carbon dioxide-polar solute system have continuous critical-mixture curves that exhibit maximums in pressure at temperatures between the critical temperatures of carbon dioxide and acetonitrile or acrylonitrile. The experimental data obtained in this study were modeled using the Peng-Robinson equation of state. Good agreement between calculated and experimental results was observed.

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Size and Uniformity Variation of Poly(MMA-co-DVB) Particles upon Precipitation Polymerization

  • Yang, Sun-Hye;Shim, Sang-Eun;Lee, Hui-Je;Kim, Gil-Pyo;Choe, Soon-Ja
    • Macromolecular Research
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    • v.12 no.5
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    • pp.519-527
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    • 2004
  • Stable poly(methyl methacrylate-co-divinylbenzene) (poly(MMA-co-DVB)) microspheres were prepared by precipitation polymerization using acetonitrile as the main medium under various polymerization conditions, including modifications of the agitation speed, monomer and initiator concentrations, DVB content in the monomer mixture, and the use of various cosolvents. Gentle agitation was required to obtain smooth spherical particles. The individually stable microspheres were obtained at monomer concentrations of up to 15 vol% in an acetonitrile medium. The number-average diameter increased linearly with respect to increases in the monomer and initiator concentrations. We found, however, that the uniformity of the microspheres was independent of the variation of the polymerization ingredients because nuclei formation was solely influenced by the crosslinking reaction of the monomers. We obtained higher yields for the polymerization at higher concentrations of monomer and initiator. The concentration of DVB in the monomer mixture composition played an important role in determining not only the size of the microspheres but also the yield of the polymerization. In addition, although we employed various cosolvents as the polymerization medium, we found that acetonitrile/2-methoxyethanol was the only system that provided spherical particles without coagulation. This finding indicates that the precipitation polymerization is strongly dependent on the solvent used as the medium.

25,27-Bis(5-chloro-3-oxapentyloxy)-p-tert-butylcalix[4]arene

  • 김종승;임정아;김성국;이수헌;김인회;김용선;추금홍;김진규;서일환
    • Korean Journal of Crystallography
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    • v.12 no.2
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    • pp.92-96
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    • 2001
  • The configuration of the title compound, $C_{52}H_{70}Cl_2O_6$, synthesized from a mixture of p-tert-calix[4]arene, tosylate of 2-(2-chloroethoxy)ethanol, $K_2CO_3$ and acetonitrile has a distorted cone conformation and the molecule is stabilized by two intramolecular hydrogen bonds between oxy-gen atoms of hydroxy groups and dichloride tails.

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Extraction of Water-Soluble Porphyrin and Metalloporphyrins into Acetonitrile by Salting-out

  • Tabata, Masaaki;Kumamoto, Midori
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.511-517
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    • 1995
  • A cationic water soluble porphyrin (5,10,15,20-tetrakis (l-methyl-pyridinium-4-yl)porphyrin, $H_2tmpyp^{4+}$) and its metalloporphyrins (MP) were easily extracted into acetonitrile separated by addition of sodium chloride ($4mol\;dm^{-3}$) in the presence of sodium perchlorate, where M denotes $Zn^{2+}$, $Cu^{2+}$, $Co^{3+}$, $Fe^{3+}$, and $Mn^{3+}$ and $P^{2-}$ is porphyrinate ion. The extracted ion-pair complexes were completely dissociated to $[MP(ClO_4)_3]^+$, and $[MP(ClO_4)_2]^{2+}$. The extraction and the dissociation constants were determined by taking into account of the partition constant of sodium perchlorate ($K_D=1.82{\pm}0.01$). The chemical properties of the separated acetonitrile phase as $E_{T(30)}$ and $D_{II,I}$ were determined and compared with other water miscible solvents (acetone, actonitrile, 1,4-dioxane, tetrahydrofuran, 1-propanol and 2-propanol). Furthermore, a sensitive and selective method was proposed for the determination of a subnanogram amount of copper(II) in natural water samples by using the present salting-out method and the porphyrins.

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High Selective Oxidation of Alcohols Based on Trivalent Ion (Cr3+ and Co3+) Complexes Anchored on MCM-41 as Heterogeneous Catalysts

  • Shojaei, Abdollah Fallah;Rafie, Mahboubeh Delavar;Loghmani, Mohammad Hassan
    • Bulletin of the Korean Chemical Society
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    • v.33 no.8
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    • pp.2748-2752
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    • 2012
  • Cr(III) and Co(III) complexes with acetylacetonate were anchored onto a mesoporous MCM-41 through Schiff condensation. The materials were characterized by XRD, FT-IR, BET, CHN and ICP techniques. Elemental analysis of samples revealed that one C=N bond was formed through Schiff condensation on MCM-41 surface. The catalysts were tested for the alcohol oxidations using t-butyl hydroperoxide (TBHP) and $H_2O_2$ as oxidant. The catalytic experiments were carried out at both room temperature and reflux condition. Various solvents such as dichloromethane, acetonitrile and water were examined in the oxidation of alcohols. Among the different solvents, catalytic activity is found more in acetonitrile. Further, the catalysts were recycled three times in the oxidation of alcohols and no major change in the conversion and selectivity is observed, which shows that the immobilized metal-acetylacetonate complexes are stable under the present reaction conditions.

Sensitive Determination of Felodipine in Human Plasma by LC-MS/MS

  • Kim, Ho-Hyun;Roh, Hyeon-Jin;Lee, He-Joo;Han, Sang-Beom
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.283.2-283.2
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    • 2003
  • This study established a highly sensitive novel quantification method for detecting felodipine in human plasma using LC-MS/MS. The mobile phase used after degassing was composed of 1 mM ammonium acetate and acetonitrile (20:80, pH 6.0), with flow rate of 200 uL/min. One mL plasma were pipetted into glass tubes and spiked with 0.1 mL of internal standard solution. (omitted)

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Theoretical Study of Solvent Effect on Yield of Oxidative Addition Reaction (산화첨가반응의 수득률에 미치는 용매효과에 관한 이론적 연구)

  • Lee, Chul-Jae;Kim, Byung-So
    • Applied Chemistry for Engineering
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    • v.21 no.5
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    • pp.586-589
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    • 2010
  • In present work, oxidative addition reaction of 1,3-cycleohexandion (1,3-CHD) with ethyl vinyl ether (EVE) was attempted utilizing $Ag_2CO_3$/celite (SC) reagent. In order to optimize reaction conditions, we surveyed several solvents for the production of dihydrofuran with the (SC) system. The yield of the acetonitrile (AN), dimethyl sulfoxide (DMSO), benzene (BZ), and heptane (HT) are given 78, 40, 15, and 10%, respectively. Therefore, we studied the solvent effects on yields by using PM3 and ZINDO/1 parameter of semi-empirical method of HyperChem7.0 molecular modeling program.

Photolysis of a New Insecticide KH-502 [O,O-diethyl O-(1-phenyl-3- trifluoromethyl-5-pyrazolyn) thiophosphoric acid ester] (신규(新規) 살충제(殺蟲劑)인 KH-502 [O,O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl) thiophosphoric acid ester]의 광(光)에 의한 분해성(分解性))

  • Cho, Boo-Yeon;Han, Dae-Sung;Yang, Jae-E
    • Korean Journal of Environmental Agriculture
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    • v.12 no.2
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    • pp.176-183
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    • 1993
  • Photolysis experiments were conducted to investigate the stability of a new insecticide, [O,O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl) thiophosphoric acid ester: KH-502] under the various conditions. In the photolysis experiment, KH-502 was, after being added into the acetone or acetonitrile solution, irradiated under the sunlight or UV lamp $(300{\sim}350nm)$, where acetone or acetonitrile solution was varied with water and $O_2$contents and was treated with humic acid, rosebengal or tryptophan. Results for stability and degradation pattern of KH-502 from the above experiment can be summarized as follows: 1. The significant difference in KH-502 decomposition due to photolysis was shown for between KH-502s irradiated at $300{\sim}350$ nm and non-irradiated. KH-502 was photolyzed in the acetone by the sensitizing effect, but was stable in the acetonitrile. 2. The degradation pattern of KH-502 in the photolysis was different as compared to that in the thermal decomposition, and the decomposed products were O,O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phosphoric acid ester (KH-502 oxo form), O,S-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phosphorothiolate(S-ethyl KH-502), 1-Phenyl-3-trifluoromethyl-5-hydroxy pyrazole (PTMHP) and several unknown compounds. 3. Treatments of acetone or acetonitrile solution with humic acid, rosebengal or tryptophan revealed no-sensitizing effect on the photolysis of KH-502. Dissolved oxygen in the acetone played as a cosensitizer with acetone competitively to enhance the photolysis of KH-502. 4. Treatments of acetone with humic acid or paddy soil water collected from fields decreased the photolysis of KH-502.

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Dicyanoanthracene and Biphenyl Co-sensitized Photooxygenation of 1,1-Diphenyl-2-vinylcyclopropane

  • Shim, Sang-Chul;Song, Jeong-Sup
    • Bulletin of the Korean Chemical Society
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    • v.7 no.2
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    • pp.150-153
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    • 1986
  • Co-sensitized photooxygenation of 1,1-diphenyl-2-vinylcyclopropane (VCP-DPh) with 9,10-dicyanoanthracene and biphenyl in oxygen-saturated acetonitrile solution produced 3,3-diphenyl-5-vinyl-1,2-dioxolane as the major product. The same photoproduct was obtained by acetone sensitized photooxygenation in oxygen-saturated acetone solution. However, VCP-DPh remained intact when directly irradiated with DCA or irradiated with Rose Bengal to generate singlet oxygen. A mechanism involving a cosensitizer radical cation and sensitizer radical anion is proposed.