• 대한화학회지
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• 제65권2호
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• pp.93-105
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• 2021

Mononuclear Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Fe(III), Ru(III), and UO2(II) complexes of 2-hydroxy-4-(p-tolyldiazenyl)benzylidene)-2-(p-tolylamino)acetohydrazide (H2L) were prepared by direct method. The ligand and its complexes were isolated in solid state and characterized by analytical techniques such as elemental and thermal analyses, molar conductance, magnetic susceptibility measurements and spectroscopic techniques such as UV-Visible, IR, 1H-NMR and 13C-NMR. The spectral data indicated that the ligand acted as neutral/monobasic bidentate or monobasic/dibasic tridentate ligand bonded to the metal ions through the oxygen atom of ketonic or enolic carbonyl group, azomethine nitrogen atom and deprotonated/protonated phenolic oxygen atom forming either tetragonally distorted octahedral or octahedral. Antimicrobial activities of the ligand and its complexes were evaluated against Escherichia coli, Bacillus subtilis and Aspergillus niger by well diffusion method. The results of antifungal activity showed that the Fe(III) complex (10) exhibited higher antifungal against Aspergillus niger than the other complexes. However, the results of antibacterial activity revealed that Cu(II) complex (4) is the most active against Escherichia coli while the Cu(II) complex (5) and Fe(III) complex (10) exhibited higher antibacterial effect on Bacillus subtilis than the other complexes.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1275-1279
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• 2010

We have carried out the surface modification of photocatalytic $TiO_2$ with triethoxysilane through dehydrogenation reaction and characterized the modified photocatalyst by spectroscopic methods, such as FT-IR, solid-state $^{29}Si$ MAS NMR, XPS, and XRF, etc. We also examined photocatalytic activity of the immobilized photocatalytic titanium dioxide with triethoxysilane by decolorization reaction of dyes such as cong red and methylene blue under visible light. Dispersion test showed that the photocatalytic titanium dioxide immobilized with triethoxysilane group has kept higher dispersibility than titanium dioxide itself. No appreciable precipitation takes place even after standing for 24 h in the 4:6 mixture ratio of ethanol and water.

• 한국재료학회지
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• 제20권11호
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• pp.600-605
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• 2010

In order to meet the requirements of faster speed and higher packing density for devices in the field of semiconductor manufacturing, the development of Cu/Low k device material is explored for use in multi-layer interconnection. SiOC(-H) thin films containing alkylgroup are considered the most promising among all the other low k candidate materials for Cu interconnection, which materials are intended to replace conventional Al wiring. Their promising character is due to their thermal and mechanical properties, which are superior to those of organic materials such as porous $SiO_2$, SiOF, polyimides, and poly (arylene ether). SiOC(-H) thin films containing alkylgroup are generally prepared by PECVD method using trimethoxysilane as precursor. Nano voids in the film originating from the sterichindrance of alkylgroup lower the dielectric constant of the film. In this study, methyltriphenylsilane containing bulky substitute was prepared and characterized by using NMR, single-crystal X-ray, GC-MS, GPC, FT-IR and TGA analyses. Solid-state NMR is utilized to investigate the insoluble samples and the chemical shift of $^{29}Si$. X-ray single crystal results confirm that methyltriphenylsilane is composed of one Si molecule, three phenyl rings and one methyl molecule. When methyltriphenylsilane decomposes, it produces radicals such as phenyl, diphenyl, phenylsilane, diphenylsilane, triphenylsilane, etc. From the analytical data, methyltriphenylsilane was found to be very efficient as a CVD or PECVD precursor.

• The Korean Journal of Ceramics
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• 제4권4호
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• pp.323-330
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• 1998

Mixed oxide compounds of potential usefulness for fibre coatings (hexagonal celsian, $BaAl_2Si_2O_8$ and lanthanum hexaluminate, $LaAl_{11}O_{18}$) or for matrix materials (yttrium aluminium garnet, $Y_3Al_5O_{12}$) were prepared by hybrid sol-gel synthesis and their thermal crystallisation was monitored by thermal analysis, X-ray diffraction and multinuclear solid state MAS NMR. All the gels convert to the crystalline phase below about $12200^{\circ}C$, via amorphous intermediates in which the Al shows and NMR resonance at 36-38 ppm sometimes ascribed to Al in 5-fold coordination. Additional information about the structural changes during thermal treatment was provided by $^{29}Si$, $^{137}Ba$ and $^{89}Y$ MAS NMR spectroscopy, showing that the feldspar framework of celsian begins to be established by about $500^{\circ}C$ but the Ba is still moving into its polyhedral lattice sites about $400^{\circ}C$ after the sluggish onset of crystallization. Lanthanum hexaluminate and YAG crystallise sharply at 1230 and $930^{\circ}C$ respectively, the former via $\gamma-Al_2O_3$, the latter via $YAlO_3$. Yttrium moves into the garnet lattice sites less than $100^{\circ}C$ after crystallisation.

• 분석과학
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• 제14권2호
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• pp.159-166
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• 2001

한외여과법을 이용하여 휴믹산(Aldrich Co.)을 분자량 별로 3개의 소부분($F_1$: 1,000-10,000 daltons; $F_2$: 10,000-50,000 daltons; $F_3$: 100,000-300,000 daltons)으로 분리한 뒤, 적외선 분광법과 고체상태 C-13 핵자기공명 분광법을 이용하여 각 소부분의 구조적 특성을 규명하였고, pH 적정법을 이용하여 각 소부분의 카르복실산 작용기 함량을 결정하였다. 휴믹산과 금속이온과의 착물 반응 특성을 규명하기 위하여, Eu(III)과 각 소부분 휴믹산과의 착화합물($[Eu(III)]=1.0{\times}10^{-4}mol\;L^{-1}$, $(HA)=470-970mg\;L^{-1}$, at pH 5.0)을 Eu(III)의 $^7F_0-{^5}D_0$ 전이를 이용한 여기 스펙트럼으로 관찰하였다. 적외선 스펙트럼과 C-13 핵자기공명 스펙트럼 분석 결과, 100,000 dalton 이상의 고분자량의 휴믹산 분자는($F_3$) 높은 지방족 탄소함량을 가지며, 50,000 daltons 이하의 저 분자량의 휴믹산($F_1$, $F_2$) 분자는 상대적으로 높은 방향족 탄소 함량을 가짐을 확인하였다. pH 적정 결과 휴믹산은 분자의 크기가 커질수록 더 낮은 카르복실기 함량을 가짐을 확인하였다. Eu(III)-휴믹산 착물의 여기스펙트럼을 Lorenzian-Gaussian 식을 이용하여 분석한 결과, 휴믹산 분자의 크기가 커질수록 최대피크의 파장 위치가 더 낮은 에너지 방향으로 이동하였다. 이러한 피크 이동의 결과는 휴믹산 분자의 크기가 커질수록 Eu(III)과 결합하는 분자내 카르복실산의 배위수가 증가함을 나타내는 것으로서, C-13 NMR 스펙트럼 분석에서 밝혀진 휴믹산 분자의 구조적인 요인과의 관련성을 밝혔다.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.605-609
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• 2003

The lower-order lithium organocyanocuprate compound, (THF)₃Li(NC)Cu($C_6$H₃-2,6-Mes₂) (1), and the bulky terphenyl Grignard reagent, Br(THF)₂Mg($C_6$H₃-2,6-Trip₂) (2), have been synthesized and structurally characterized both in the solid state by single crystal x-ray crystallography and in solution by multi-nuclear NMR and IR spectroscopy. The compound (1) was isolated as a monomeric contact ion-pair in which the C (organic ipso)-Cu-CN-Li atoms are coordinated linearly. The lithium has a tetrahedral geometry as a result of solvation by three THF molecules. The compound (1) is the first example of fully characterized monomeric lower order lithium organocyanocuprate. The bulky Grignard reagent (2) was also isolated as a monomer in which the magnesium, solvated by two THF molecules, has a distorted tetrahedral geometry. The crystals of (1) possess triclinic symmetry with the space group $P{\={1}}$, Z = 2, with a = 12.456(3) Å, b = 12.508(3) Å, c = 13.904(3) Å, α = 99.81°, β = 103.72(3)°, and γ = 119.44(3)°. The crystals (2) have a monoclinic symmetry of space group $P2_{1/C}$, Z = 4, with a = 13.071(3) Å, b = 14.967(3) Å, c = 22.070(4) Å, and β = 98.95(3)°.

• Korean Chemical Engineering Research
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• 제49권2호
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• pp.181-186
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• 2011

본 연구에서는 실리카 나노 입자의 표면 개질을 위해 실란 커플링제인 3-(trimethoxysilyl)propylmethacrylate(MPS) 를 사용하여 표면 개질 반응을 수행하였다. 용매의 pH, MPS의 가수 분해 반응시간, 표면 개질 반응시간 및 실리카 표면의 실라놀기(Si-OH)에 대한 MPS의 몰 비를 변화하여 각각의 반응조건이 실리카 표면개질 반응에 미치는 영향을 연구하였다. 개질반응 후 Fourier Transform Infrared Spectroscopy(FTIR), 원소분석(EA) 및 고체 상태 cross-polarization magic angle spinning(CP/MAS) Nuclear Magnetic Resonance Spectroscopy(NMR)법을 사용하여 표면이 개질된 실리카 입자들의 분석을 수행하였다. 연구 결과 용매의 pH가 4.5일 때 MPS가 단량체 형태로 실리카 표면의 실라놀기와 반응하고 이외의 pH에서는 MPS가 이량체, 삼량체 혹은 사량체의 올리고머 형태로 실리카의 실라놀기와 반응함이 우세함을 나타내었다. 가수분해반응 시간을 30분에서 90분으로 증가시키면 MPS가 올리고머 형태로 실리카 표면의 실라놀기와 반응하는 것이 우세하고, 투입한 MPS 몰 비의 증가도 MPS가 올리고머 형태로 실리카 표면의 실라놀기와 반응하는 것이 우세함을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.3031-3038
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• 2011

Ion-coordinating ruthenium complexes [cis-Ru(dcbpy)(L)(NCS)$_2$, where dcbpy is 4,4'-dicarboxylic acid-2,2'-bipyridine and L is 1,4,7,10-tetraoxa-13-azacyclopentadecane, JK-121, or bis(2-(2-methoxy-ethoxy)ethyl) amine, JK-122] have been synthesized and characterized using $^1H$ NMR, Fourier transform IR, UV/vis spectroscopy, and cyclic voltammetry. The effect of $Li^+$ in the electrolyte on the photovoltaic performance was investigated. With the stepwise addition of $Li^+$ to a liquid electrolyte, the device shows significant increase in the photo-current density, but a small decrease in the open circuit voltage. The solar cell with a hole conductor, the addition of $Li^+$ resulted in a 30% improvement in efficiency. The JK-121 sensitized cells in the liquid and solid-state electrolyte give power conversion efficiencies of 6.95% and 2.59%, respectively, under the simulated sunlight.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2583-2588
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• 2013

A new type of solid and gel-state ionics based on siloxane pyridinium iodides was synthesized and used as electrolytes in dye-sensitized solar cells. The resulting electrolytes were characterized by $^1H$ NMR spectroscopy, TGA and diffusion coefficient. The synthesized siloxane pyridinium iodide electrolytes have characteristics of different chain length of siloxane moieties. The ion conductivities were given 2.7-3.2 S/cm. Among the three SiDPIs based electrolytes, DSSC employing the SiDPI2 gives an open circuit voltage of 0.704 V, a short-circuit current of 15.85 $mA/cm^2$ and conversion efficiency of 6.8% under light intensity of 100 $mW/cm^2$. In addition, the performance of the DSSCs showed relatively reasonable compared with the propylpyridinium iodide (PPI) electrolyte.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1283-1288
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• 2010

A novel polyaminopolycarboxylate ligand with many coordination sites, N,N,$N^1,N^1,N^2,N^2$-[( 2,4,6-tri(aminomethyl)-pyridine]hexakis(acetic acid) (TPHA), was designed and synthesized and its lanthanide complexes $Na_6Tb_2$(TPHA)$Cl_6{\cdot}14H_2O$, $Na_6Eu_2$(TPHA)$Cl_6{\cdot}8H_2O$, $Na_6Gd_2$(TPHA)$Cl_6{\cdot}11H_2O$ and $Na_6Sm_2$(TPHA)$Cl_6{\cdot}9H_2O$ were successfully prepared. The ligand and the complexes were characterized by elemental analysis, IR, mass, NMR and TG-DTA. The TG-DTA studies indicated that the complexes had a high thermal stability, whose initial decomposition temperature was over $270^{\circ}C$. The luminescence properties of the complexes in solid state were investigated and the results suggested that $Tb^{3+}$ and $Eu^{3+}$ ions could be sensitized efficiently by the ligand, especially the Tb(III) complex displayed a very strong luminescence intensity (> 10000) and only displayed characteristic metal-centered luminescence. Also, the correlative comparison between the structure of ligand and luminescence properties showed how the number of the coordination atoms of ligand can be a prominent factor in the effectiveness of ligand-to-metal energy transfer.