• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.796-800
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• 2004

The structure of [Cu(tpen)]$(ClO_4)_2$ (tpen = N,N,N',N'-tetrakis(2-pyridylmethyl)-1,2-ethanediamine) has been identified by X-ray crystallography. The copper(II) ion is surrounded by two amine N atoms and three pyridine N atoms of the ligand, making a distorted trigonal-bipyramid. Among the six potential N donor atoms (two amine N and four pyridine N atoms), only one pyridine N atom remains uncoordinated. We examined structural changes on addition of $Cl^-$ to $[Cu(tpen)]^{2+}$(1). The addition of $Cl^-$ in methanol resulted in the formation of a novel dinuclear copper(II) complex $[Cu_2Cl_2(tpen)](ClO_4)_2{\cdot}H_2O$. The structure of the dinuclear complex was verified by X-ray crystallography. Each copper(II) ion in the dinuclear complex showed a distorted square planar geometry with two pyridine N atoms, one amine N atom and one $Cl^-$ ion.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.1037-1040
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• 2011

The dinuclear complex 1 with cooperative hydrogen bonds can be prepared by the metal-directed reaction of Eq. (2). This work shows that the coordinated hydroxyl group trans to the secondary amino group is deprotonated more readily than that trans to the tertiary amino group and acts as the hydrogen-bond accepter. The lattice water molecules in 1 act as bridges between the two mononuclear units through hydrogen bonds. The complex is quite stable as the dimeric form even in various polar solvents. The complex exhibits a weak antiferromagnetic interaction between the metal ions in spite of relatively long Cu$\cdots$Cu distance. This strongly supports the suggestion that the antiferromagnetic behavior is closely related to the cooperative hydrogen bonds.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4231-4234
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• 2012

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1113-1117
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• 2009

The one-dimensional coordination polymers, $[Cu^{II}(L)(NO_3)_2]_n$ (1) and {$[Cu^{II}(L)(NO_3)]{\cdot}2H_2O}_{2n} (2), were synthesized from $Cu(NO_3)_2{\cdot}3H_2O$ and 2-[(pyridin-3-ylmethyl)amino]ethanol (L, PMAE) in methanol by controlling the molar ratio of copper(II) salt. Copper(II) ion in 1 has one pyridine group of PMAE whose an aminoethanol group coordinates adjacent copper(II) ion. As the pyridine group is bonded to neighboring copper(II) ion, 1 becomes a one-dimensional chain. Contrary to 1, the structure of 2 shows that the oxygen atom of ethoxide group is bridged between two copper(II) ions, which forms a dinuclear complex. Additionally, the pyridine group of PMAE included one dinuclear unit is coordinated to the other dimeric one each other, which leads to a one-dimensional polymer. Due to the structural differences, 1 exhibits weak antiferromagnetic interaction, while 2 shows strong antiferromagnetic interaction. Due to direct spin exchange via oxygen of PMAE 2 has a much strong spin coupling than 1.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.269-272
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• 2014

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.255-258
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• 2013

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3233-3238
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• 2013

Two new Cu(II) complexes, $[Cu_2(acpy-mdtc)_2(HBA)(ClO_4)]{\cdot}H_2O$ (1) (acpy-mdtc- = 2-acetylpyridine S-methyldithiocarbamate and $HBA^-$ = benzilic acid anion) and $[Cu_2(acpy-phtsc)_2(HBA)]{\cdot}ClO_4$ (2) (acpy-$phtsc^-$ = 2-acetylpyridine 4-phenyl-3-thiosemicarbazate) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The X-ray analysis reveals that the structures of 1 and 2 are dinuclear copper(II) complexes bridged by two thiolate sulfur atoms of Schiff base ligand and bidentate bridging $HBA^-$ anion. For 1, each of the two copper atoms has different coordination environments. Cu1 adopts a five-coordinate square-pyramidal with a $N_2OS_2$ donor, while Cu2 exhibits a distorted octahedral geometry in a $N_2O_2S_2$ manner. For 2, two Cu(II) ions all have a five-coordinate square-pyramidal with a $N_2OS_2$ donor. In each complex, the Schiff base ligand is coordinated to copper ions as a tridentate thiol mode.

• Korean Journal of Crystallography
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• v.17 no.2
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• pp.46-50
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• 2006

The dinuclear copper(II) complex {[Cu(pmea)Cl][Cu$(H_2O)_3]}Cl_2{\cdot} H_2O$ (1) (Hpmea=bis(2-pyridvlmethyl)amino-2-ethanoic acid) has been synthesized and characterized. It crystallizes in the monoclinic system $P2_1/c$, a=9.0008(6) ${\AA}$, b=28.0171(19) ${\AA}$, c=8.5590(6) ${\AA}$, $\beta$=104.2280(10)$^{\circ}$, V=2092.2(2) ${\AA}^3$, Z=4. Crystal structure of 1 reveals a syn-anti carboxylate-bridged dinuclear complex, in which the coordination environment around each copper atom exhibits a distorted square-pyramid and a distorted square plane, respectively.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.49-52
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• 2011

A dinuclear copper(II) complex of [$Cu_2(aceace)_4$(dipyph)] [aceace = acetylacetone, dipyph = 1,4-di(4-pyridylethene-2-yl-)benzene] has been synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction. It crystallizes in the monoclinic system, space group P21/c, with lattice parameters a = 7.9584(16) $\AA$, b = 18.594(4) $\AA$, c = 15.063(4) $\AA$ $\beta=120.97(2)^o$ and $M_r$ = 807.85 ($C_{40}H_{44}Cu_2N_2O_8$), Z = 2. Each of the $Cu^{2+}$ ion adopts a square pyramid geometry and coordinates with four oxygen atoms from two aceace ligands and one nitrogen atom from dipyph bidentate ligand. Magnetic measurement shows that the Weiss constant and Curie constant for the title compound are -0.22 K and 0.1154 emu K/mol, respectively. Thermal stability data indicate that the title complex undergoes two steps decomposition and the residue is $Cu_2O_4$. In the potential range of -1.5 ~ 0.8 V, the title complex represents an irreversible electrochemical process.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2043-2048
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• 2014

Two isomers of a new tetraaza macrotricycle 2,2,4,9,9,11-hexaazamethyl-1,5,8,12-tetraazatricyclo[$10.2.2^{5.8}$]-octadecane ($L^2$) containing additional N-$CH_2CH_2$-N linkages, C-meso-$L^2$ and C-racemic-$L^2$, have been prepared by the reaction of 1-bromo-2-chloroethane with C-meso-$L^1$ or C-racemic-$L^1$ ($L^1$ = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). Both C-meso-$L^2$ and C-racemic-$L^2$ react with copper(II) ion to form $[Cu(C-meso-L^2)]^{2+}$ or $[Cu(C-racemic-L^2)]^{2+}$ in dehydrated ethanol, but do not with nickel(II) ion under similar conditions. Crystal structure of [Cu(C-racemic-$L^2$)($H_2O$)]$(ClO_4)_2$ shows that the complex has distorted square-pyramidal coordination geometry with an apically coordinated water molecule. Unexpectedly, the Cu-N distances [2.016(3)-2.030(3) ${\AA}$] of [Cu(C-racemic-$L^2$)($H_2O$)]$(ClO_4)_2$ are longer than those [1.992(3)-2.000(3) ${\AA}$] of [Cu(C-racemic-$L^1$)($H_2O$)]$(ClO_4)_2$. As a result, $[Cu(C-racemic-L^2)(H_2O)]^{2+}$ exhibits weaker ligand field strength than $[Cu(C-racemic-L^1)(H_2O)]^{2+}$. The copper(II) complexes readily react with CN- ion to yield the cyano-bridged dinuclear complex $[Cu_2(C-meso-L^2)_2CN]^{3+}$ or $[Cu_2(C-racemic-L^2)_2CN]^{3+}$. Spectra and chemical properties of $[Cu(C-meso-L^2)]^{2+}$ and $[Cu_2(C-meso-L^2)_2CN]^{3+}$ are not quite different from those of $[Cu(C-racemic-L^2)]^{2+}$ and $[Cu_2(C-racemic-L^2)_2CN]^{3+}$, respectively.