• Bulletin of the Korean Chemical Society
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• 제29권10호
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• pp.1905-1910
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• 2008

The reaction of 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[16.4.0$0^{1.18}.0^{7.12}$]docosane ($L^1$) with formaldehyde in warm methanol yielded 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[16.4.$1^{2.6}.0^{1.18}.0^{7.12}$]tricosane ($L^7$) containing one 1,3-diazacyclohexane subunit. In methanol, $L^7$ readily reacts with $Cu^{2+}$ ion to form [$CuL^7(H_2O)$]$^{2+}$ which is extremely inert against methanolysis. In the solution containing $Ni^{2+}$ ion, however, $L^7$ reacts with methanol to yield [$NiL^3$]$^{2+}$ ($L^3$ = 2-(methoxymethyl)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.$0^{1.18}.0^{7.12}$]- docosane), in which one N-$CH_2OCH_3$ pendant arm is appended. The copper(II) complex [$CuL^7(H_2O)$]- $(ClO_4)_2{\cdot}3H_2O\;(I{\cdot}3H_2O)$ has a severely distorted trigonal bipyramidal coordination geometry with a 4-5- 6-5 chelate ring sequence. The crystal structure of [$NiL^3$]$(PF_6)_2{\cdot}2H_2O$ (IIb) shows that the N-$CH_2OCH_3$ pendant arm is not coordinated to the metal ion in the solid state. In various solvents (S), however, the nickel(II) complex exists as a mixture of [$NiL^3$(S)]$^{2+}$, in which the N-$CH_2OCH_3$ group as well as S is coordinated to the metal ion, and [$NiL^3$]^{2+}.

• Korean Chemical Engineering Research
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• 제44권4호
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• pp.369-374
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• 2006

$V_2O_5$와 AlMCM-48을 고체상에서 반응시킨 후 소성하면 메조포러스 물질 내에서 V(V) 화학종이 아주 약하게 나타난다. 그러나 환원 과정을 거치면 EPR로 조사할 수 있는 바나딜 $VO^{2+}$ 화학종이 생성된다. $VO^{2+}-AlMCM-48$에 들어있는 바나듐의 화학적 환경을 XRD, EDX, UV-Vis, EPR, $^{29}Si$ and $^{27}Al$ and $^{51}V$ NMR로 조사하였다. 탈수하거나 CO 로 환원하면 바나듐은 MCM-48에 유사 사면체형 $VO^{2+}$ 바나딜 이온 상태로 존재하며 물이 배위되면 찌그러진 팔면체구조로 바뀐다.

• 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.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2923-2928
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• 2010

This study examined the synthesis of the crystal structure of bis(2,2'-bipyridine)nitrato zinc (II) nitrate, $[Zn(bipy)_2(NO_3)]^+NO_3^-$ using a microwave treatment at 300 W and 60 Hz for the application to dye-sensitized solar cells. The simulated complex structure of the complex was optimized with the density functional theory calculations for the UV-vis spectrum of the ground state using Gaussian 03 at the B3LYP/LANL2DZ level. The structure of the acquired complex was expected a penta-coordination with four nitrogen atoms of bipyridine and the oxygen bond of the $NO_3^-$ ion. The reflectance UV-vis absorption spectra exhibited two absorptions (L-L transfers) that were assigned to the transfers from the ligand ($\sigma$, $\pi$) of $NO_3$ to the ligand ($\sigma^*$, $\pi^*$) of pyridine at around 200 - 350 nm, and from the non-bonding orbital (n) of O in $NO_3$ to the p-orbital of pyridine at around 450 - 550 nm, respectively. The photoelectric efficiency was approximately 0.397% in the dye-sensitized solar cells with the nanometer-sized $TiO_2$ at an open-circuit voltage (Voc) of 0.39 V, a short-circuit current density (Jsc) of $1.79\;mA/cm^2$, and an incident light intensity of $100\;mW/cm^2$.

• 대한화학회지
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• 제36권6호
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• pp.824-831
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• 1992

수용액에서 Ho(III) 이온과 간단한 리간드 사이의 착물 형성에 대한 온도와 리간드 농도의 영향을 흡수 스펙트럼을 이용하여 연구하였다. Hypersensitive 전이$(^5I_8\;\to\;^5G_6)$의 전이세기 변화는 온도와 리간드의 영향을 크게 받고, 이 변화는 Ho(Ⅲ) 이온의 배위 환경 변화로 해석될 수 있다. 이 스펙트럼에서 관찰된 전이세기를 분석하여 Judd-Ofelt 전이세기 파라미터($\Omega_\lambda$, $\lambda$ = 2, 4, 6)를 구했다. 이 파라미터들 중 $\Omega_2$ 파라미터가 온도와 리간드에 의해 가장 큰 변화를 보이고, 이 변화로부터 $Cl^-$와 ${NO_3}^-$가 수용액에서 내부권 착물을 형성함을 보였다

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1809-1814
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• 2006

The L-Valinate anion coordinating zinc complex, [$Zn(val)_2(H-2O)$], was isolated and structurally characterized by single crystal X-ray crystallography. The crystal possess orthorhombic symmetry with a space group $P2_12_12_1$, Z = 4, and a = 7.4279(2)$\AA$, b = 9.4342(2)$\AA$, c =20.5862(7)$\AA$ respectively. The compound features a penta-coordinate zinc ion in which the two valine anion molecules are directly coordinating the central zinc metal ion via their N (amine) and O (carboxylate) atoms, and an additional coordination to zinc is made by water molecule (solvent) to form a distorted square pyramidal structure. In addition, further synthesis of the valine capped ZnS:Mn nanocrystal from the reaction of [$Zn(val)_2(H-2O)$] precursor with $Na_2S$ and 1.95 weight % of $Mn^{2+}$ dopant is described. Obtained valine capped nanocrystal was water dispersible and was optically characterized by UV-vis and solution PL spectroscopy. The solution PL spectrum for the valine capped ZnS:Mn nanocrystal showed an excitation peak at 280 nm and a very narrow emission peak at 558 nm respectively. The measured and calculated PL efficiency of the nanocrystal in water was 15.8%. The obtained powders were characterized by XRD, HR-TEM, and EDXS analyses. The particle size of the nanocrystal was also measured via a TEM image. The measured average particle size was 3.3 nm.

• 분석과학
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• 제18권5호
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• pp.386-390
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• 2005

The zinc(II) complex, $Zn(NCS)_2(C_3H_4N_2S)_2$, I, has been synthesized and characterized by single crystal X-ray diffraction, thermal analysis and infrared spectroscopy. The complex I crystallizes in the triclinic system, $P\bar{1}$ space group with a = 7.587(1), b = 8.815(1), $c=12.432(2){\AA}$, ${\alpha}=75.584(8)$, ${\beta}=83.533(9)$, ${\gamma}=68.686(8)^{\circ}$, $V=750.0(2){\AA}^3$, Z = 2, $R_1=0.036$ and ${\omega}R_2=0.101$. The central Zn(II) atom has a tetrahedral coordination geometry, with the heterocyclic nitrogen atoms of 2-aminothiazole ligands and the nitrogen atoms of isothiocyanate ligands. The crystal structure is stabilized by one-dimensional networks of the intermolecular $N-H{\cdots}S$ hydrogen bonds between the amino group of 2-aminothiazole ligands and the sulfur atom of isothiocyanate ligands. Based on the results of thermal analysis, the thermal decomposition reaction of complex I was analyzed to have three distinctive stages such as the loss of 2-aminothiazole, the decomposition of isothiocyanate and the formation of metal oxide.

• 대한화학회지
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• 제30권5호
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• pp.475-482
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• 1986

$Ni^{2+}$와 D-penicillamine사이의 착물형성반응에 대한 반응속도 및 평형에 관한 수용액중에서 실시하였다. 속도론적 실험은 압력-급변법을 사용하여 pH8~9범위에서 실시하였다. D-Penicillamine은 질소와 유황원자를 주게로 하여 pH＞9.2조건에서 $Ni^{2+}$이온에 배위하나 pH값 8.25∼9.07범위에서 총괄 안정도 상수값이 급격히 감소하며 비해리된 mercapto기가 결합에 참여하지 않는 것으로 밝혀졌다. 또한 이 착물 형성반응에 있어 율속단계는 $Ni^{2+}$이온의 내부 배위권으로 부터 물분자가 유리되는 과정임이 밝혀졌다.

• 대한화학회지
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• 제51권3호
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• pp.240-243
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• 2007

8배위 이트륨(III) 화합물 Y(tpb)3(H2O)2을 합성하였고 X-선 회절법으로 구조를 규명하였다. 이 화합물은 12 면체의 구조를 가지며, 두 면(Y-O2-O1-O5-O6 and Y-O4-O3-O8-O7)사이의 각은 89.59o이다. 또한, O1-O5과 O3-O8 의 거리는 2.965 and 2.995 A이며 O2-O6과 and O4-O7의 거리는 4.256 and 4.403 A이다.

• 대한화학회지
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• 제27권2호
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• pp.117-126
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• 1983

탄소-13 및 바나듐-51 핵자기공명분광법을 이용하여 아미노폴리카르본산-바나듐(v) 착물의 용액 내에서의 구조에 대해 연구하였다. 이 때 사용한 리간드는 ethylenediaminetetraacetic acid (EDTA), trans-cyclohexanediaminetetraacetic acid (CDTA), 1,2-propylenediaminetetraacetic acid (PDTA), ethylenediaminediacetic acid (EDDA), 2-hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentacetic acid (DPTA), nitrilotriacetic acid (NTA) 등이었다. 모든 리간드는 바나듐(Ⅴ)과 시스-VO2핵을 함유하는 정8면체 구조의 1:1 착물을 생성하였다. 바나듐(V)과 시스-$VO_2$ 핵을 함유하는 정8면체 구조의 1:1 착물을 생성하였다. 바나듐(V)에 대한 히드록시에틸기의 배위는 아세테이트기의 배위에 비해 덜 바람직함을 알 수 있었다. 그리고 EDDA 및 PDTA는 각각 2가지의 이성체착물들을 생성함을 알 수 있었다.