• Bulletin of the Korean Chemical Society
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• v.20 no.4
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• pp.427-430
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• 1999

The Grignard coupling reaction of bis(chloromethyl)diorganosilanes [(ClCH2)2SiR1R2: R1 = R2 = Me, la; R1 = Me, R2 = Ph, lb; R1 = R2 = Ph, lc] with diorganodichlorosilanes [(Cl2SiR3R4: R3 = R4 = Me, 2a; R3 = Me, R4 = Ph, 2b; R3 = R4 = Ph, 2c] at THE reflux temperature gave the intermolecular C-Si coupling product of 1,1,3,3-tetraorgano-1,3-disilacyclobutanes 3a-f in poor to moderate yields ranging from 7% to 50% along with polydiorganosilapropanes. The cyclization reaction of la-c with methyl-substituted dichlorosilanes 2a, b gave 1,3-disilacyclobutanes 3a-c, e, d in moderate yields (42-50%), while the same reaction with dichlorodiphenylsilane (2c) to 1,3-disilacyclobutanes 3d, f resulted in low yield (7-18%) probably due to the steric hindrance of two-phenyl groups on the silicon of 2c.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1464-1466
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• 2008

Tetrabutylammonium Fluorodichloroplumbate(II), N$(C_4H_9)_4$[$PbCl_2F$], TBAFDiCP and Tetrabutylammonium Fluorodiiodoplumbate(II), [$(C_4H_9)_4$N][$PbI_2F$], TBAFDiIP are the first examples of fluoroplumbate salts that have been prepared from the reaction of $(C_4H_9)_4$NF with $PbCl_2$ and $PbI_2$ respectively using either $CH_3CN$ solvent. These new compound characterized by elemental analysis, IR, UV/Visible, $^1H$ NMR, and $^{19}F$ NMR techniques.

• Journal of the Korean Ceramic Society
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• v.13 no.2
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• pp.3-7
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• 1976

Influences of chlorides(CaCl2, MgCl2, NaCl) on the colouring effect of Fe component in white portland cement was investigated. Chlorides enhance the whiteness of the white portland cement owing to volatilization of Fe2O3 and translation of ferrite composition toward C2F. This translation is caused by consumption of alumina at the formation of C12A7, the formation of which is promoted in the presence of chloride. With decrease of p in ferrite composition C6F1-pAp, transfer of Fe3+ from 4 to 6 coordinated cite is occurred, and as a result, whiteness is raised. Hydration process of the cement containing a small amount of chloride differs little from the one without chloride.

• Korean Journal of Plant Resources
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• v.24 no.6
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• pp.719-723
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• 2011

Antimicrobial activities of methanol, ethanol, water, and $CH_2Cl_2$ extracts from Fritillaria unibracteata Hsiao et K.C. Hsia and F. ussuriensis Maxim. were investigated by disk-agar diffusion method. The result showed comparatively strong antimicrobial activity against several microorganisms. The extracts from F. unibracteata and F. ussuriensis dosedependently increased the activity. However, water and $CH_2Cl_2$ extracts showed no antimicrobial activity against 7 microorganisms. Especially, against the most sensitive microorganism Staphylococcus epidermidis, methanol extracts at highest concentration of 20 mg/mL exhibited the largest clear zone on plate by 6-12 mm and ethanol extracts on plate by 6-10 mm.

• 한국포장학회:학술대회논문집
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• 2006.11a
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• pp.95-101
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• 2006

거창사과원예협동조합에서 구입한 사과 600상자를 5% $CaCl_2$ 용액에 각각 15분간 침지하는 방법으로 전처리 후 24시간 건조시키고 무포장구, $25{\mu}m$ 두께의 기능성 MA 필름으로 포장한 포장구와 무처리 무포장구인 대조구로 나누어 $0^{\circ}C$의 저온저장고로 옮겨 7개월 동안 저장하면서 3주 간격으로 품질을 분석하였다. 저장 기간이 증가할수록 중량 감소율은 Control 구보다 $CaCl_2$구와 $CaCl_2+MA$구의 중량 감소율이 월등히 낮았다. 경도변화는 저장 기간이 증가할수록 감소하는 경향을 보였으며, 그 중 $CaCl_2$구는 초기치 0.97 $kg_f$에서 저장 18주에는 0.95 $kg_f$로 초기치에 비해 2%의 가장 적은 변화를 보였다. 산도는 대조구보다 처리구의 산도가 높게 나타났으나 큰 차이는 나타나지 않았다. 가용성 고형분 함량은 저장 기간 모든 실험구에 따른 큰 차이가 없었다. 비타민 C 함량은 저장기간이 지날수록 모든 실험구에서 감소하는 경향을 보였으며, 기호도 조사에서 $CaCl_2$구와 $CaCl_2+MA$구가 대조구보다 유의적으로 높게 나타났다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.217-220
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• 2001

The possibility of cerium dioxide (CeO$_{7}$ ) thin films as insulators of metal erroelectric insulator semiconductor (MFIS) structures have been studied. The etching CeO$_2$ thin films have been performed in an inductively coupled C1$_2$/CF$_4$/Ar plasma. The high etch rate of the CeO$_2$ thin film was 250 ${\AA}$/m at a 10% addition of Cl$_2$ into the Ar(80)/CF$_4$(20). The surface reaction of the etched CeO$_2$ thin films was investigated using X-ray photoelectron spectroscopy (XPS) analysis. There are Ce-Cl and Ce-F bonding by chemical reaction between Cl, F and Ce. These products can be removed by the physical bombardment of incident Ar ions.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.641-646
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• 2012

We used the hybrid density-functional (B3LYP/6-31G(d,p)) method to analyze the substitution patterns of $C_{20}H_{18}X_2$ derivatives (X = F, Cl, Br, or OH) obtained as disubstituted $C_{20}H_{20}$ cages. Our results suggest that the cis-1 regioisomers (1,2-dihalo derivatives) are less stable than the trans-1 regioisomers (1,20-dihalo derivatives), whereas in the case of the dihydroxy derivatives, the cis-1 regioisomer is more stable than the trans-1 regioisomer. This implies that in the dihalo-induced strain cages of $C_{20}H_{18}X_2$, the strain effect would affect the relative energies, while in the dihydroxide, the hydrogen bonds have a stronger effect on the relative energies in cis-1 regioisomer than the strain effect do. Thus this supports the experimental result in which the bisvicinal tetrol was of particular preparative-synthetic interest as a substitute for the lacking bisvicinal tetrabromide. Further, the topologies of the HOMO and LUMO characteristics of all $C_{20}H_{18}Cl_2$ and $C_{20}H_{18}Br_2$ regioisomers with the same symmetry are same, but they are different from those of $C_{20}H_{18}F_2$ and $C_{20}H_{18}(OH)_2$. This indicates that the five regioisomers of each $C_{20}H_{20}$ disubstituted derivative will have an entirely different set of characteristic chemical reactions.

• Journal of the Korean Chemical Society
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• v.44 no.2
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• pp.127-137
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• 2000

Eleven new compounds that are composed of bis(p-substituted phenyl) terephthalate unitand the decyloxy pendant as lateral were synthesized and their thermal and liquid crystalline properties were studied by the differential scanning calorimetry (DSC) and on a hot-stage of a polarizing microscope. The ter-minal substituent groups of the compound were varied; X= -H(II-H), -F(lI-F), -CII(II-CI), -Br(ll-Br), -I(II-I), -$NO_2(lI-NO_2$), $-CF_3(II-CF_3$), -$OC_2H_5(II-OC_2H_5$), -$OC_4H_9(II-OC_4H_9$), -$C_6H_5(Il-C_6H_5$). The compounds of $II-OC_2H_5,\;II-OC_4H_9$ and $II-C_6H_5$ were monotropically nematic. In contrast, the compounds of Il-H, II-F, II-Cl, II-Br, II-I, $lI-NO_2$, $II-CF_3$, and II-CN did not show liquid crystalline properties.

• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.391-395
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• 1986

MNDO calculations were carried out to determine reactant complexes and transition states of the $S_N2$ reactions of $CH_3X\;+\;Y^-\;{\to}\;CH_3Y\;+\;X^-$ where X = F, Cl, CN and Y = CN, OH, F, Cl. The leaving group ability was found to vary inversely with the activation barrier, which in turn was mainly ascribable to the deformation energies accompanied with bond stretching of C-X bond and inversion of $CH_3$ group. The nucleophilicity was shown to be in the order $Cl^->F^->OH^->CN^-$ but the effect on the activation barrier was relatively small compared with that of the leaving group. The bond breaking and bond formation indices and energy decomposition analysis showed that the TS for the reaction of $CH_3$Cl occurs in the early stage of the reaction coordinate relative to that of $CH_3$F. It has been shown that the potential energy surface (PES) diagrams approach can only accommodate thermodynamic effects but fails to correlate intrinsic kinetic effects on the TS structure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.9
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• pp.714-719
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• 2001

SrBi$_2$Ta$_2$$O_{9}$ thn films were etched in inductively coupled Cl$_2$/CF$_4$/Ar plasma. THe maximum etch rate was 1060 $\AA$/min at a Cl$_2$/(Cl$_2$+CF$_4$+Ar)=0.2. The 20% additive Cl$_2$ into CF$_4$/Ar plasma decreased carbon and fluorine radicals, but increased Cl radicals. Sr was effectively removed by reacting with Cl radical because the boiling point of SrCl$_2$(125$0^{\circ}C$) is lower than that of SrF$_2$(246$0^{\circ}C$). The chemical reactions on the etched surface were studied with x-ray photoelectron spectroscopy and secondary ion mass spectrometry. The etching profile was evaluated by using scanning electron microscopy.y.