• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.483-486
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• 2008

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1743-1746
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• 2010

• 대한화학회지
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• 제30권6호
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• pp.526-531
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• 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.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1477-1483
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• 2004

We present the tandem mass spectrometry applications carried out to elucidate the coordination structure of Zn(II) bound lysine ternary complexes, $(Zn+Lys+Lys-H)^+$, which is a good model system to represent a simple (metallo)enzyme-substrate complex (ES). In particular, experimental efforts were focused on revealing the involvement of a lysine side chain ${\varepsilon}$-amino group in the coordination of $Zn^{2+}$ divalent ions. MS/MS fragmentation pattern showed that all the oxygen species within a complex fell off in the form of $H_2O$ in contrast to those of other ternary complexes containing amino acids with simple side chains (4-coordinate geometries, Figure 1a), suggesting that the lysine complexes have different coordination structures from the others. The participation of a lysine basic side chain in the coordination of Zn(II) was experimentally evidenced in MS/MS for $N{\varepsilon}$-Acetyl-L-Lys Zn(II) complexes with acetyl protection groups as well as in MS/MS for the ternary complexes with one $NH_3$ loss, $(Zn+Lys+Lys-NH_3-H)^+$. Detailed structures were predicted using ab initio calculations on $(Zn+Lys+Lys-H)^+$ isomers with 4-, 5-, and 6-coordinate structures. A zwitterionic 4-coordinate complex (Figure 7d) and a 5-coordinate structure with distorted bipyramidal geometry (Figure 7b) are found to be most plausible in terms of energy stability and compatibility with the experimental observations, respectively.

• 대한화학회지
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• 제60권5호
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• pp.321-326
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• 2016

Two new polymeric complexes, [Zn(dpa)(pyz)_0.5]_n (1; dpa = diphenate and pyz = pyrazine) and [Mn₃(bpdc)₃(py)₄]_n (2; bpdc = biphenyl-4,4'-dicarboxylate and py = pyridine) were successfully isolated by the hydro- and solvo-thermal technique, respectively. The complexes were characterized by elemental and thermal analysis, vibrational IR spectroscopy, and by single crystal x-ray structure determination. For 2, magnetic property was also investigated. Complex 1 is a two-dimensional layer structure consisting of a paddle-wheel building unit of Zn-dpa chains bridged by pyrazine. While, complex 2 consists of linear trimeric Mn3 cluster as building unit to form 3D network. In the complexes, dpa²⁻ (1) and bpdc²⁻(2) ligands show a typical bis-monodendate bridging and two kinds of bridging modes; a typical bridging and chelating/bridging mode, respectively.

• Bulletin of the Korean Chemical Society
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• 제15권9호
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• pp.774-776
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• 1994

Ab initio studies of simple model systems for the carboxypeptidase A active site indicate that penta-and hexa-coordinate Zn(II) complexes have comparable structural stabilities. These facile coordination structures can be responsible for the catalytic role. Although the hexa-coordinate Zn(II) complex is more stable in enthalpy than the penta-coordinate Zn(II) complex, the entropy effect makes the latter as stable as or slightly more stable in free energy than the former.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.2069-2072
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• 2010

• 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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• 제18권3호
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• pp.189-193
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• 1974

세자리 schiff base 리간드로서 salicylidene imino-o-thiobenzene은 salicylaldehyde와 o-aminothiolbenzene을 Duff reaction 시킴으로써 합성하였으며 이 리간드와 Cu(II), Ni(II), 및 Zn(II) 이온들과의 반응으로서 새로운 착물 Cu(II)$[C_{13}H_9ONS]{\cdot}3H_2O$, 및 Ni(II)$[C_{13}H_9ONS]{\cdot}3H_2O,\;Zn(II)[C_{13}H_9ONS]{\cdot}3H_2O$들을 합성하였다. 이 착물들은 가시부 자외선스펙트럼, 적외선스펙트럼, TGA, DTA 및 원소분석측정에 의하여 리간드와 금속은 1:1 몰비로 착물을 이루며 Cu(II) 착물은 1수화물 4배위 결합착물이고 Ni(II), 및 Zn(II) 착물은 3수화물, 6배위 결합의 착물임을 알아보았다.

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.725-732
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• 2006

A rapid flotation methodology for zinc(II) separation and enrichment from human biofluids is established. At pH 6.0 and ambient temperature, using oleic acid (HOL) as a foaming reagent, zinc(II) was separated with phenanthraquinone monophenyl thiosemicarbazone (PPT) as a new flotation collector for Zn(II). The floated red colored 1 : 2 Zn(II)-PPT complex was measured spectrophotometrically at 526 nm with a molar absorptivity of $1.83 \;{\times}\; 10^5\; L$ mol $L ^{-1}\;cm ^{-1}$. Beer's law was obeyed over a concentration range 0.05-1.0 mg $L ^{-1}$ in the aqueous as well as in the scum layers. The proposed preconcentration flotation methodology was applied to determine Zn(II) in human biofluids. Application was, also, extended to determine Zn(II) in pharmaceutical samples and natural water samples spiked with known amounts of Zn(II) with a preconcentration factor of 100 and a detection limit of 10 ng m$L ^{-1}$. The method was verified by comparison of the spectrophotometric results with flame atomic absorption spectrometric (AAS) measurements. Moreover a postulation for the mechanism of flotation is proposed.