• Journal of the Korean Chemical Society
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• v.38 no.8
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• pp.570-575
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• 1994

The metallation of $\alpha$-methylpyridine 1(a∼f) with n-BuLi produced $\alpha-methylenylpyridinium$ salt 3(a∼f) by elimination of butane. The trapping reactions of 3(a∼f) with $Me_3SiCl\;and\;Me_2SiClCH(SiMe_3)CH_2tBu$ produced only 4(a∼f) and 5(a∼f). The $\alpha$-hydrogen atom of silylated methylene group in 4(a∼f) is more reactive than unreacted $CH_3$ of 4(a∼f) itself and 1(a∼f) toward n-BuLi at low temperature in pentane medium.

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.638-643
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• 2006

Pyrolytic reaction study of dichloromethane ($CH_{2}Cl_{2}$) in excess hydrogen was performed to investigate pyrolytic reaction pathways at a pressure of 1 atm with residence times of 0.3~2.0 sec in the temperature range of $525{\sim}900^{\circ}C$. A constant feed molar ratio $CH_{2}Cl_{2}$:$H_{2}$ of 4:96 was maintained through the experiment. Reagent loss and product formation were monitored by using an on-line gas chromatograph, where batch samples were analyzed by GC/MS. Complete destruction(99%) of the parent reagent was observed at temperature near $780^{\circ}C$ with residence time over 1 sec. Major products observed were $CH_{3}Cl$, $CH_{4}$, $C_{2}H_{4}$, $C_{2}H_{6}$, and HCl. Minor products included $CHClCCl_{2}$, CHClCHCl, $CH_{2}CHCl$, and $C_{2}H_{2}$. The pyrolytic reaction pathways to describe the important features of intermediate product distributions and reagent loss, based upon thermodynamic and kinetic principles, were suggested. The results of this work provided a better understanding of pyrolytic decomposition processes which occur during the pyrolysis of $CH_{2}Cl_{2}$ and similar chlorinated methanes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.7
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• pp.589-593
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• 2011

[ $SnO_2$ ]nano powders were prepared by solution reduction method using tin chloride($SnCl_2{\cdot}2H_2O$), hydrazine($N_2H_4$) and NaOH. The $SnO_2$ thick films for gas sensors were fabricated by screen printing method on alumina substrates and annealed at $300^{\circ}C$ in air, respectively. XRD patterns of the $SnO_2$ nano powders showed the tetragonal structure with (110) dominant orientation. The particle size of $SnO_2$ nano powders at the ratio of $SnCl_2:N_2H_4$+NaOH= 1:6 was about 60 nm. The sensing characteristics were investigated by measuring the electrical resistance of each sensor in a test box. Sensitivity of $SnO_2$ gas sensor to 5 ppm $CH_4$gas and 5 ppm $CH_3CH_2CH_3$ gas was investigated for various $SnCl_2:N_2H_4$+NaOH proportion. The highest sensitivity to $CH_4$ gas and $CH_3CH_2CH_3$ gas of $SnO_2$ sensors was observed at the $SnCl_2:N_2H_4$+NaOH= 1:8 and $SnCl_2:N_2H_4$+NaOH= 1:6, respectively. Response and recovery times of $SnO_2$ gas sensors prepared by $SnCl_2:N_2H_4$+NaOH= 1:6 was about 40 s and 30 s, respectively.

• Bulletin of the Korean Chemical Society
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• v.18 no.4
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• pp.402-405
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• 1997

Olefinic and cyclopropyl group substituted arenes (C6H5Y) react with [Cp*Ir(CH3COCH3)3]A2 (A=ClO4-, OTf-) to give η6-arene complexes, [Cp*Ir(η6-C6H5Y)]2+ (1a: Y=-CH=CH2 (a),-CH=CHCH3 (b),-C(CH3)=CH2 (c),-CH-CH2-CH2 (d)). Complex 1b-1d are readily converted into η3-allyl complexes, [Cp*(CH3CN)Ir(η3-CH(C6H5)CHCH2)]+ (2a) and [Cp*(CH3CN)Ir(η3-CH2(C6H5)CH2)]+ (2b), in the presence of Na2CO3 in CH3CN. The η6-styrene complex, 1a reacts with NaBH4 to give η5-cyclohexadienyl complex, [Cp*Ir(η5-C6H6-CH=CH2)]+ (3), while with H2 it gives η6-ethylbenzene complex [Cp*Ir(η6-C6H5CH2CH3)]2+ (4). Complex 1a and 1c react with HCl to give [Cp*Ir(η6-C6H5CH2CH2Cl)]2+ (5a) and [Cp*Ir(η6-C6H5CH(CH3)CH2Cl]2+ (5b), respectively.

• Bulletin of the Korean Chemical Society
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• v.8 no.3
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• pp.179-183
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• 1987

Reactions of $Rh(ClO_4)(CO)(AsPh_3)_2$ with unsaturated nitriles and aldehyde, L, produce a series of new cationic rhodium (I) complexes, $[RhL(CO)(AsPh_3)_2]ClO_4$ (L = $CH_2$ = CHCN, $CH_2$ = C($CH_3$)CN, trans-$CH_3CH$ = CHCN, $CH_2$ = CH$CH_2$CN, trans-$C_6H_5CH$ = CHCN, and trans-$C_6H_5CH$ = CHCHD) where L are coordinated through the nitrogen and oxygen, respectively but not through the ${\pi}$-system of the olefinic group. Dissociation constants for the reaction, $[RhL(CO)(AsPh_3)_2]ClO_4$ $\rightleftharpoons$ $Rh(ClO_4)(CO)(AsPh_3)_2$ + L, have been measured to be $1.20{\times}10^{-4}$ M (L = $CH_2$ = CHCN), $1.05{\times}10^{-4}$ M (L = $CH_2$ = C($CH_3$)CN, $3.26{\times}10^{-5}$ M (L = trans-$CH_3$CH = CHCN) and $6.45{\times}10^{-5}$ M (L = $CH_2$ = CH$CH_2$CN) in chlorobenzene at $25^{\circ}C, and higher than those of triphenylphosphine complexes, $[RhL(CO)(AsPh_3)_2]ClO_4$ where L are the corresponding nitriles that are coordinated through the nitrogen atom. The differences in dissociation constants seem to be predominantly due to the differences in ${\Delta}H$ (not due to the differences in ${\Delta}S$). The weaker Rh-N (unsaturated nitriles) bonding in $AsPh_3$ complexes than in $PPh_3$ complexes (based on ${\Delta}H$ values) suggests that the unsaturated nitriles in 2∼5 are good ${\sigma}$-donor and poor ${\pi}$-acceptor.

• Bulletin of the Korean Chemical Society
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• v.20 no.4
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• pp.422-426
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• 1999

The Grignard reactions of bis(chloromethyl)dimethylsilane (1) with trimethylchlorosilane (2) in THF give both the intermolecular C-Si coupling and intramolecular C-C coupling products. At beginning stage, 1 reacts with Mg to give the mono-Grignard reagent ClCH2Me2SiCH2MgCl (1) which undergoes the C-Si coupling reaction to give MC2Si(CH2SiMe3)2 3, or C-C coupling to a mixture of formula Me3SiCH2(SiMe2CH2CH2)nR1 (n = 1, 2, 3, ..; 4a, R1I = H: 4b, R1 = SiMe3). In the reaction, two reaction pathways are involved: a) Ⅰ reacts with 2 to give Me3SiCH2SiMe2CH2Cl 6 which further reacts with Mg to afford a Me2SiCH2Mel-SiCH2MgCl (Ⅱ) or b) I cyclizes intramolecularly to a silacyclopropane intermediate A, which undergoes a ring-opening polymerization by the nucleophilic attack of the intermediates I or Ⅱ, followed by the termination reaction with H2O and 2, to give 4a and 4b, respectively. As the mole ratio of 2/1 increased from 2 to 16 folds, the formation of product 3 increased from 16% to 47% while the formation of polymeric products 4 was reduced from 60% to 40%. The intermolecular C-Si coupling reaction of the pathway a becomes more favorable than the intramolecular C-C coupling reaction of the pathways b at the higher mole ratio of 2/1.

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.565-578
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• 1992

It has been suggested that Hg$^{2+}$-promoted reaction of a series of cis-[Co(en)$_2$(L)Cl]$^{2+}$ (en = 1,2-diaminoethane) with L = NH$_3$, NH$_2$CH$_3$, glyOC$_2$H$_5$, glyOCH$_3$, dl-alaOC$_2$H$_5$, NH$_2$CH$_2$CONH$_2$, and NH$_2$CH$_2$CN proceeds by dissociative interchange(I$_d$) mechanism from kinetic data, circular dichroism spectra, analyses of products, and the values of m(Grunwald-Winstein plot) using Y (solvent ionizing power) in aqueous solution and in mixed aqueous-organic solvent. It has been found that chloride replacement by water (aquation) for the series with L = NH$_3$ and NH$_2$CH$_3$ and chelation of ligand L to Co(Ⅲ) for the series with L = glyOC$_2$H$_5$, glyOCH$_3$, dl-alaOC$_2$H$_5$, NH$_2$CH$_2$CONH$_2$, and NH$_2$CH$_2$CN occurs, respectively. The rate constants on Hg$^{2+}$-induced reaction of the series except cis-[Co(en)$_2$(NH$_2$CH$_2$CN)Cl]$^{2+}$ were increased with increasing the contents of ethanol in mixed water-ethanol solvents. In mixed water-30${\%}$ organic solvents, the rate constants of the series except cis-[Co(en)$_2$(NH$_2$CH$_2$CN)Cl]$^{2+}$ have also been measured in the order 30${\%}$ 2-propanol-water > 30${\%}$ ethanol-water > water. However, the rate constants of cis-[Co(en)$_2$(NH$_2$CH$_2$CN)Cl]$^{2+}$ were reversed. The rate constants of the series with L= NH$_3$ and NH$_2$CH$_3$ were related to ligand field parameter (${\Delta}$), but those of the series with L = glyOC$_2$H$_5$, glyOCH$_3$, dl-alaOC$_2$H$_5$, NH$_2$CH$_2$CONH$_2$, NH$_2$CH$_2$CN were not. The reaction between the series and Hg2+ in aqueous media containing NO$_3^-$ has been investigated. The results for the reaction do not alter the mechanism, but the rate only was altered.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.4
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• pp.135-139
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• 2004

The layered organic-inorganic hybrid compounds($C_6H_5CH_2NH_3)_2CuCl_4$ and ($NH_3C_6/H_4C_2H_4_6/H_4NH_3)CuCl_4$ have been directly synthesized. From the X-ray diffraction data and the organic guest size, the orientation of the intercalated organic amine was determined. The inorganic sheets consist of $CuCl_4^{2-}$layers of comer-sharing octahedra copper chloride. The protonated organic amine was intercalated into the $CuCl_4^{2-}$layers with bilayer structure for ($C_6H_5CH_2NH_3)_2CuCl_4$ and monolayer structure for ($NH_3C_6/H_4C_2H_4_6/H_4NH_3)CuCl_4$.

• Nuclear Engineering and Technology
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• v.9 no.1
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• pp.33-38
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• 1977

The molecular orbital theory (EHT) has been applied to the discussion of the reaction mechanism and reactivity of p-substituted phenyl-$\beta$-chloroethyl-sulfones, R-(equation omitted)-$SO_2CH_2CH_2Cl$, where R are $CH_3O\;,CH_3$, Cl, H. The theoretical conclusion derived are in good agreements with the experimental order.

• Bulletin of the Korean Chemical Society
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• v.8 no.3
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• pp.185-189
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• 1987

Reactions of $Ir(ClO)_4(CO)(PPh_3)_2$ with dicyano olefins, cis-NCCH = CH$CH_2$$CH_2$CN (cDC1B), trans-NCCH = CH$CH_2$$CH_2$CN (tDC1B), trans-NC$CH_2$CH = CH$CH_2$CN (tDC2B), and NC$CH_2$$CH_2$$CH_2$$CH_2$CN (DCB) produce binuclear dicationic iridium (I) complexes, $[(CO)(PPh_3)_2Ir-NC-A-CN-Ir(PPh_3)_2(CO)](ClO_4)_2$ (NC-A-CN = cDC1B (1a), tDC1B (1b), tDC2B (1c), DCB (1d)). Complexes 1a-1d react with hydrogen to give binuclear dicationic tetrahydrido iridium (Ⅲ ) complexes, $[(CO)(PPh_3)_2(H)_2Ir-NC-A-CN-Ir(H)_2(PPh_3)_2(CO)](ClO_4)_2$ (NC-A-CN = cDC1B (2a), tDC1B (2b), tDC2B (2c), DCB (2d)). Complexes 2a and 2b catalyze the hydrogenation of cDC1B and tDC1B, respectively to give DCB, while the complex 2c is catalytically active for the isomerization of tDC2B to give cDC1B and tDC1B and the hydrogenation of tDC2B to give DCB at $100^{\circ}C$.