• Bulletin of the Korean Chemical Society
• /
• 제23권6호
• /
• pp.824-829
• /
• 2002

New di-N-cyanomethylated tetraaza macrocycle 2.13-bis(cyanomethyl)-5.16-dimethyl-2,6,13,17-tetraazatricyclo[$16.4.0.0^7.12$]docosane $(L^2)$ has been prepared by the reaction of 3, 14-dimethyl-2,6,13,17-tetraazatricyclo $(L^1)$ with bromoacetonitrile. The square-planar complexes $[ML^2](ClO_4)_2(M=Ni(II)$ or Cu(II) can be prepared by the reaction of $L^2$ with the corresponding metal ion in acetonitrile. The cyanomethyl groups of $[ML^2](ClO_4)_2readily$ react with water to $yield[ML^3](ClO_4)_2$ containing pendant amide groups. The trans-octahedral complexes $[ML^4](ClO_4)_2$, in which two imidate ester groups are coordinated to the metal ion, can be also prepared by the reaction of $[ML^2](ClO_4)_2with$ methanol under mild conditions. The hydrolysis and alcoholysis reactions of $[ML^2](ClO_4)_2are$ promoted by the central metal ion, in spite of the fact that the cyanomethyl group is not involved in intramolecular coordination. The reactions are also promoted by a base such as triethylamine but are retarded by an $acid(HClO_4).Interestingly$, the imidate ester groups of $[ML^4]^2$ are unusually resistant to hydrolysis even in 0.1 M $HCIO_4$ or 0.1 M NaOH aqueous solution. Crystal structure of $[NiL^4](ClO_4)_2shows$ that the Ni-N (pendant imidate ester group) bond is rlatively strong; the Ni-N bond distance is shorter then the Ni-N(tertiary) distance and is similar to the Ni-N (secondary) distance.

• 대한화학회지
• /
• 제30권6호
• /
• pp.526-531
• /
• 1986

95% 메탄올 용액에서 코발트(II), 니켈(II), 구리(II)와 아연(II)이온들과 1,15-diaza-3,4:12,13-dibenzo-5,8,11-trioxacycloheptadecane (NenOdien H$_4$, L)리간드와의 안정도 상수를 전위차 적정법으로 25$^{\circ}$C 에서 결정하였다. 그 결과 착물의 형성은 리간드내의 주게원자의 영향을 받으며 안정도 상수의 크기는 Co(II) < Ni(II) < Cu(II) > Zn(II)의 순위이였다. 한편 고체착물의 구조를 분광광도법, 원소분석 및 전기전도도법의 결과로부터 논의하였다. 그 결과 고체상태의 화학조성과 기하구조는 팔면체의 $[CoL_2(OH_2)Cl]Cl{\cdot}2H_2O$, 팔면체의 $[NiL_2(OH_2)Cl]Cl{\cdot}2H_2O$, 사각피라밋형의 [CuLCl]Cl, 그리고 팔면체의 $[ZnLCl_2]{\cdot}\frac{1}{2}H_2O$임을 알 수 있었다.

• 한국세라믹학회지
• /
• 제23권1호
• /
• pp.27-32
• /
• 1986

This study is aimed at synthsizing high dielectric material (Ba, Sr)$TiO_3$ through direct wet process. Pure and ultra fine particle of (Ba, Sr)$TiO_3$ Powder was synthesized from $BaCl_2$ $SrCl_2$ and TiCl4 aqeous solution at KOH Solution in the $N_2$ gas atmosphere. $BaCl_2$ $SrCl_2$ and TiCl4 were Mixed with the mole ratio of 1:9, 3:7:10, 5:5:10, 7:3:10, 9:1:10 and sythesized at 4$0^{\circ}C$~9$0^{\circ}C$ for 10min~15hrs. The particle size particle shape crystallinity and synthesis condition of (Ba, Sr)$TiO_3$ powder with the variation of temperature and reaction time in the aqueous solution studied by the exprimental instruments of DTA. TGA, X-ray diffratometer SEM.

• 한국세라믹학회지
• /
• 제37권10호
• /
• pp.944-948
• /
• 2000

TiCl$_4$, 물 및 propanol의 혼합용액으로부터 가수분해하여 미립의 TiO$_2$분말을 제조할 때 HPC 첨가와 HPC 존재하에서 TiCl$_4$mole 농도 및 유기용매 처리를 했을 때 입자크기, 응집성 및 형태 등을 관찰하였다. HPC는 TiO$_2$합성시 steric dispersant로 작용하여 응집을 적게 하는 경향을 나타내었고 HPC를 첨가한 상태에서 TiCl$_4$의 mole 농도 변화는 입자크기에 크게 영향을 주었는데 TiCl$_4$mole 농도가 증가함에 따라 입자크기는 증가하였다. 또한 유기용제 처리는 분산 효과가 있었다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.1128-1133
• /
• 2004

A comprehensive experimental and numerical study has been conducted to understand the influence of $CH_{3}Cl$ addition on $CH_{4}/O_{2}/N_{2}$ premixed flames under the oxygen enrichment. The laminar flame speeds of $CH_{4}/CH_{3}Cl/O_{2}/N_{2}$ premixed flames at room temperature and atmospheric pressure are experimentally measured using Bunsen nozzle flame technique, varying the amount of $CH_{3}Cl$ in the fuel, the equivalence ratio of the unburned mixture, and the level of the oxygen enrichment. The flame speeds predicted by a detailed chemical kinetic mechanism employed are found to be in excellent agreement with those deduced from experiments. As $CH_{3}Cl$ addition is increased temperature at the postflame is not almost varied but the heat release rate and $EI_{NO}$ are decreased. The function of $CH_{3}Cl$ as inhibitor on hydrocarbon flames becomes weakened as the level of the oxygen enrichment is increased from 0.21 to 0.5.

• 반도체디스플레이기술학회지
• /
• 제10권1호
• /
• pp.95-99
• /
• 2011

$(1-x)BaTiO_3+(x)Cd_5(PO_4)_3Cl$ ceramics were prepared by the conventional ceramic technique, i.e., solid state reaction at high temperature. The concentration of $Cd_5(PO_4)_3C$ was varied from 0.01 to 0.15 mole fraction. In order to study the phase transitions of our ceramics, the Raman scattering spectra were measured as functions of concentration x and temperature. It was found that the soluble limit of $Cd_5(PO_4)_3Cl$ in $BaTiO_3$ was the x=0.05 composition and $BaTiO_3$ phase disappeared above x=0.10. A new phase identified as $Ba_4Ti_3P_2O_{15}$ was detected in all samples of our compositions. The Curie temperature shifts up to $130^{\circ}C$ as the concentration x increases from zero to 0.05 and shift down to $95^{\circ}C$ as further increases to 0.08. For the increase of the Curie temperature, it is suggested that it can result from the inhibition of displacement of $Ti^{4+}$ in the distorted octahedron due to well dispersed $Ba_4Ti_3P_2O_{15}$ and $Cd_5(PO_4)_3Cl$ phase.

• 한국자기학회지
• /
• 제5권1호
• /
• pp.54-57
• /
• 1995

넓은 범위의 $^{1}H$ 핵자기공명 자기장에서 Heisenberg 반강자성체인 $MnCl_{2}.4H_{2}O$에 대하여 상온 수소 핵자기완화를 연구하였다. $MnCl_{2}.4H_{2}O$는 상온에서 밀접한 상자성 $Mn^{++}$ 이온계이지만 희박한 상자성계에서 예상되는 특성을 보인 반면에 희박한 상자성 근사와 매우 다른 결과도 보였다. 또한 수소 원자핵들은 0.7 T의 외부자기장 부근에서 스핀-격자 완화시간의 이상거동을 보였다.

• 한국전기전자재료학회논문지
• /
• 제16권6호
• /
• pp.449-453
• /
• 2003

Ferroelectric YMnO$_3$ thin films were etched with Ar/Cl$_2$ and CF$_4$/Cl$_2$ inductively coupled plasma (ICP). The maximum etch rate of YMnO$_3$ thin film was 300 $\AA$/min at a Ar/Cl$_2$ gas mixing ratio of 2/8, a RF power of 800 W, a DE bias of 200 V, a chamber pressure of 15 mTorr, and a substrate temperature of 30 $^{\circ}C$. From the X-ray photoelectron spectroscopy (XPS) analysis, yttrium etched by chemical reactions with Cl radicals assisted by Ar ion bombardments in Ar/Cl$_2$ plasma. In CF$_4$/Cl$_2$ plasma, yttrium are remained on the etched surface of YMnO$_3$ and formed of nonvolatile YF$_{x}$ compounds manganese etched effectively by chemical reactions with Cl and F radicals. From the X-ray diffraction (XRD) analysis, the (0004) diffraction peak intensity of the YMnO$_3$ thin film etched in Ar/Cl$_2$ plasma shows lower value than that in CF$_4$/Cl$_2$ plasma. It indicates that the crystallinty of YMnO$_3$ thin film is more easily damaged by the Ar ion bombardment than the changes of stoichiometry due to nonvolatile etch by-products.s.

• 반도체디스플레이기술학회지
• /
• 제8권2호
• /
• pp.55-58
• /
• 2009

Density functional theory was used to investigate the adsorption and reaction of $HfCl_4$ with two hydroxyls on Si (001)-$2{\times}1$ surface in atomic layer deposition (ALD) process. We prepared a reasonable Si substrate which consisted of six inter-dimer dissociated $H_2O$ molecules and two intra-dimer dissociated $H_2O$ molecules. The $HfCl_4$must react with two hydroxyls to be a bulk-like structure. When $HfCl_4$ was adsorbed on a hydroxyl, there was energy benefit of -0.55 eV. Though there was energy loss for $HfCl_4$ to react with H of hydroxyl, thermal energy of ALD chamber would be enough to pass the energy barriers. There were five reaction pathways for $HfCl_4$ to react with two hydroxyls; inter-dimer, intra-dimer, cross-dimer, inter-row, and cross-row. Inter-row, inter-dimer and intra-dimer were relatively favorable among the five reaction pathways based on the energy difference. The electron densities between O and Hf in these three reactions were higher than the others and they had shorter Hf-O and O-O bond lengths than the other two reaction pathways.

• 대한화학회지
• /
• 제54권4호
• /
• pp.402-410
• /
• 2010

새로운 착물인 cis-[$Mo_2O_3(Hapdhba)_2$], trans-[$UO_2(Hapdhba)_2$], [Pd(Hapdhba)Cl($H_2O$)], [Pd(bpy)(Hapdhba)]Cl, [Ag(bpy) (Hapdhba)], [$Ru(Hapdhba)_2(H_2O)_2$], [$Rh(Hapdhba)_2Cl(H_2O)$] 및 [Au(Hapdhba)$Cl_2$]를 보고한다. 여기서 $H_2$apdhba는 2-aminopyrimidine 및 2,4-dihydoxybenzaldehyde에서 비롯된 Schiff-염기이다. 이들 착물은 IR, UV-Vis 그리고 질량 스펙트럼을 비롯하여 전기전도도, 자기 및 열 분석을 통해 특성을 조사하였다. 구리의 부식에 대한 $H_2$apdhba의 방해효과는 0.5 M HCl에서 potiodynamic polarization 측정을 통해 조사하였다.