• Journal of Applied Biological Chemistry
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• 제49권3호
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• pp.86-89
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• 2006

The novel tetranuclear nickel (II) complex is a high rate accelerator in promoting hydrolysis of phosphate diesters. Nickel-bound bis-nitrophenyl phosphate (BNPP) can be $10^4$ times more reactive than the unbound BNPP. The large rate of enhancements by the complex slightly under basic condition has shown high catalytic activity in phosphate diester cleavage. The bell-shaped pH-rate profile indicated that the nickel-oxide form of the tetranuclear complex or its kinetic equivalent was the active species for cleaving BNPP. The catalytic hydrolysis between tetranuclear nickel (II) complex and phosphate diester proceeds via the formation of bidentate coordination of the anionic phosphate to the Ni (II) atom. This reveals that the complex has the possibility as artificial nuclease.

• Bulletin of the Korean Chemical Society
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• 제29권12호
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• pp.2540-2542
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• 2008

• Bulletin of the Korean Chemical Society
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• 제25권5호
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• pp.673-675
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• 2004

The tetranuclear copper(II) cluster compound $[Cu_4OCl_6(C_{14}H_{12}N_2)_4]$ has been synthesized by hydrothermal reaction and studied by X-ray diffraction. The four copper(II) atoms locate four capsheaves of a tetrahedral skeletal structure and a oxygen atom as interstitial atom occupies the center position of the same tetrahedron, and each edge of the Cu-Cu tetrahedron is bridged by one ${\mu}_2$-Cl anion. The copper atom possesses slightly distorted trigonal bipyramidal geometry with three ${\mu}_2$-Cl atoms in equatorial position and the interstitial O atom and one N atom from 3-benzyl-benzimidazole ligand occupying axial position. The Cu-Cu distances are in the range of 3.0986-3.1162 ${\AA}$. The EPR spectrum suggested that the copper(II) ground state $d_{x2-y2}$ and the coordination geometry was trigonal bipyramidal.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.1965-1969
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• 2014

A new tetranuclear Mn(III) complex $[Mn^{III}{_4}(sae)_4({\mu}_3-O)({\mu}_{1,1}-N_3)(OH)(H_2O)_2]{\cdot}H_2O$ (1) ($H_2sae$ = 2-salicylideneamino-1-ethanol) has been synthesized by the reaction of $MnCl_2{\cdot}4H_2O$, $H_2sae$ and sodium azide in the mixed solvent of methanol, acetonitrile and water. The X-ray diffraction analysis shows that the four Mn(III) ions in complex 1 have a unique adamantine arrangement, whereas the coordination environment of each Mn(III) ions is different. Magnetic studies indicate that complex 1 manifests antiferromagnetic behaviors. The magnetic susceptibilities of complex 1 have been fitted by two magnetic models based on the suitable analysis of its magnetic structural topology.

• Bulletin of the Korean Chemical Society
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• 제26권2호
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• pp.253-259
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• 2005

[$(tacn)_4Fe_4O_2(OH)_4]_2{\cdot}8Br{\cdot}9H_2O$ (tacn = 1,4,7-triazacyclononane), a tetranuclear iron(III) complex was synthesized by the hydrolysis of (tacn)FeCl3 and crystallizes in the orthorhombic space group, Pca2(1), with cell parameters, a = 37.574(3) $\AA$, b = 16.9245(12) $\AA$, c = 14.2830(11) $\AA$, V = 9082.9(12) ${\AA}^3$. [$(tacn)_4Fe_4O_2(OH)_4]^{4+}$ cations approach S4 point symmetry containing an adamantane skeleton. Four Fe(III) atoms have distorted octahedral environments with two hydroxo and an oxo bridges. Two [$(tacn)_4Fe_4O_2(OH)_4]^{4+}$ clusters having different Fe…Fe distances are connected to each other by the networked hydrogen bonds. The electrochemical behavior reveals irreversible three cathodic and two anodic peaks. Magnetic properties are characterized by antiferromagnetic (AF) interactions between Fe(III) ion spins. However, the low-lying states are still magnetic and exhibit a blocking behavior and a magnetic hysteresis at low temperatures.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3843-3846
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• 2013

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.137-143
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• 1993

The tetranuclear heterometallic complex CpMo$Os_3(CO)_{10}({\mu]-H)2[{\mu}3-{\eta}^2-C(O)CH_2Tol]\;(1,\;Cp={\eta}^5-C_5H_5,\;Tol=p-C_6H_4Me)$ has been examined by variable-temperature $^{13}$C-NMR spectroscopy and by a full three-dimensional X-ray structual analysis. Complex 1 crystallizes in the orthorhombic space group Pna2$_1$ with a = 12.960(1) ${\AA}$, b = 11.255(l) ${\AA}$, c = 38.569(10)${\AA}$, V = 5626(2) ${\AA}^3$ and ${\rho}$(calcd) = 2.71 gcm$^{-3}$ for Z = 8 and molecular weight 1146.9. Diffraction data were collectedon a CAD4 diffractometer, and the structure was refined to $R_F$ = 9.7% and $R_{W^F}$ = 9.9% for 2530 data (MoK${\alpha}$ radiation). There are two essentially equivalent molecules in the crystallographic asymmetric unit. The tetranuclear molecule contains a triangulated rhomboidal arrangement of metal atoms with Os(2) and Mo at the two bridgehead positions. The metal framework is planar; the dihedral angle between Os(l)-Os(2)-Mo and Os(3)-Os(2)-Mo planes is 180$^{\circ}$. A triply bridging (${\mu}_3,\;{\eta}^2$) acyl ligand lies above the Os(l)-Os(2)-Mo plane; the oxygen atom spans the two bridgehead positions, while the carbon atom spans one bridgehead position and an acute apical position. The molecular architecture is completed by an ${\eta}^5$-cyclopentadienyl ligand and a semi-triply bridging carbonyl ligand on the molybdenum atom, and nine terminal carbonyl ligands-four on Os(3), three on Os(l), and two on Os(2). The two hydride ligands are inferred to occupy the Os(l)-Os(2) and Mo-Os(3) edges from structural and NMR data.

• Bulletin of the Korean Chemical Society
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• 제25권8호
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• pp.1241-1243
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• 2004

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1937-1940
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• 2004

• 대한화학회지
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• 제39권7호
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• pp.552-558
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• 1995

배위자인 이소부틸, 노르말 부틸 및 메틸티오아세트아미드옥심과 출발 물질인 단핵 및 다핵 착물과의 반응에서 $X_2[M_{O4}O_12{R'C(NH_2)NO}_2](X=n-Bu_4N^+$, $R'=(CH_3)_2CH$, $CH_3CH_2CH_2$, $CH_3SCH_2$; $X=(CH_3)_2CHC(=NH_2)NH_2^+$, $R'=(CH_3)_2CH$; $X=CH_3CH_2CH_2C(=NH_2)NH_2^+$, $R'=CH_3_CH_2CH_2$; $X=CH_3SCH_2C(=NH_2)NH_2^+$, $R'=CH_3SCH_2)$을 합성하였다. 합성한 착물은 원소분석, 적외선 및 핵자기공명에 의해 구조를 규명하였다. 얻은 착물중 ${(CH_3)_2CHC(NH_2)_2}_2[M_{O4}O_{12}{(CH_3)_2CHC(NH_2)NO}_2]$은 X-선 단결정 회절에서 결정구조를 밝혔고, 얻은 데이타는 Monoclinic, $P2_{1/c}$, $a=10.168(3){\AA}$, $b=11.768(1){\AA}$, $c=13.557(1){\AA}$, ${\beta}=102.08(1)^{\circ}$, $V=1586.2(5){\AA}^3$, Z = 2이었고, 회절강도 2951개($F_0>3s(F_0)$)에 대한 최종 신뢰도 인자는 0.026이었다. 이 착물의 구조는 평면상의 환형$[Mo_4({\mu}-O)_4]$과 두 개의 ${\mu}_4$-아미드옥시메이트로 구성되어 있다.