• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3617-3622
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• 2010

The reaction of stoichiometric amount of $FeCl_2{\cdot}4H_2O$, (2-pyridylmethyl, 3-pyridylmethyl)amine (2,3-pyma) and sodium azide/sodium thiocyanate in methanol under aerobic conditions affords the dinuclear Fe(III) complexes, [(2,3-pyma) $(N_3)_2Fe({\mu}-OCH_3)_2Fe(N_3)_2$(2,3-pyma)]${\cdot}CH_3OH$ (1) and [(2,3-pyma)$(NCS)_2Fe({\mu}-OCH_3)_2Fe(NCS)_2$(2,3-pyma)] (2) in good yield. Two bis-methoxy-bridged diiron(III) complexes are isolated and characterized. The coordination geometries around iron(III) ions in 1 and 2 are the same tetragonally distorted octahedron. The iron(III) ions are coordinated by two nitrogens of a 2,3-pyma, two nitrogens of two azide/thiocyanate ions, and two oxygens of two methoxy groups. Both compounds are isomorphous. The structures of 1 and 2 display the C-$H{\cdots}\pi$ and/or $\pi-\pi$ stacking interactions as well as hydrogen bonding interactions, respectively. Compounds 1 and 2 show significant antiferromagnetic couplings through the bridged methoxy groups between the iron(III) ions in the temperature range from 5 to 300 K ($H=-2JS_1{\cdot}S_2$, J=-19.1 and $-13.9\;cm^{-1}$ for 1 and 2).

• Polymer(Korea)
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• v.24 no.2
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• pp.159-167
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• 2000

The polymethylene-bridged dinuclear half-titanocenes [(CH$_2$)$_{n}$(C$_{5}$ H$_4$)$_2$][TiCl$_3$]$_2$ (n=5(10), 7(11), 9(12)) have been synthesized by treating the distannylated derivatives of the ligands with two equivalents of TiCl$_4$ in toluene. All complexes are characterized by IR, $^1$H NMR, $^{13}$ C NMR and mass spectrometry. In order to examine the catalytic properties of the dinuclear complexes styrene polymerization has been conducted in the presence of MMAO. From the polymerization experiments it was found that ( i ) all the prepared complexes 10-12 produced syndiotactic polystyrenes, ( ii ) the complex 12 holding the longest bridging ligand exhibited the highest activity but produced a polymer having the smallest molecular weight among the polymethylene-bridged dinuclear half-titanocenes. This behavior was attributed to the influence of electron-donating caused by the polymethylene bridge between two active centers as well as the effect of steric congestion around metal center caused by the proximal distance between two active sites.s.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4321-4326
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• 2011

A new series of heteroleptic cyclometalated iridium(III) complexes has been synthesized and characterized by absorption, emission and cyclic voltammetry studies: $(pqx)_2Ir(acac)$ (1), $(dmpqx)_2Ir(acac)$ (2) and $(dfpqx)_2Ir(acac)$ (3) where pqx=2-phenylquinoxalinate, dmpqx=2-(2,4-dimethoxyphenyl)quinoxalinate, dfpqx=2-(2,4-difluorophenyl) quinoxalinate and acac=acetylacetonate anion. The reaction of excess acetylacetone with ${\mu}$-chloride-bridged dimeric iridium complex, $[(C\^N)_2Ir({\mu}-Cl)]_2$, gives a complex 1 and an unusual hydridoiridium(III) complex, $(pqx)IrH(acac)_2$ (4). The complex 1, 2 and 3 show their emissions in an orangered region (${\lambda}_{PL,max}$ = 583-616 nm), and the emission maxima can be tuned by the change of substituent at phenyl ring of 2-phenylquinoxaline ligand. The phosphorescent line shape indicates that the emissions originate predominantly from $^3MLCT$ states with little admixture of ligand-based $^3({\pi}-{\pi}^*)$ excited states. The structures of complex 3 and 4 are additionally characterized by a single crystal X-ray diffraction method. The complex 3 shows a distorted octahedral geometry around iridium(III) metal ion. A strong trans influence of the phenyl ring is examined. In complex 4, there are two discrete molecules which are mirror images each other at the ratio of 1:1 in an unit cell. We propose that the phosphorescent complex 1, 2 and 3 are possible candidates for the phosphors in OLEDs applications.

• Bulletin of the Korean Chemical Society
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• v.23 no.8
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• pp.1106-1109
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• 2002

Studies on subtle spacer ligand effects of AgCF3SO3 with 3,3'-Py2X (X = O vs S) have been carried out. The reaction of AgCF3SO3 with 3,3'-Py2O and 3,3'-Py2S produces [Ag(CF3SO3)(3,3'-Py2O)] and [Ag(3,3'-Py2S)] (CF3SO3), respectively. Crystallographic characterization of [Ag(CF3SO3)(3,3'-Py2O)] (monoclinic P1, a =8.405(2) $\AA$, b = 10.714(2) $\AA$, c = 18.031(2) $\AA$, $\alpha=$ 77.36(2), $\beta=107.83(2)^{\circ}$, $\gamma=$ 66.92(2), V = 1438.0(5) $\AA3$ , Z =2,R = 0.0486) reveals that the skeletal structure is an anion-bridged double-strand. The double-strands are packed like a plywood. The framework of [Ag(3,3'-Py2S)](CF3SO3) (orthorhombic Pcab, a = 17.330(2) $\AA$, b = 8.640(1) $\AA$, c = 19.933(6) $\AA$, V = 2985(1) $\AA3$ , Z =8, R = 0.0437) is a sinusoidal single-strand. The formation of each coordination polymer appears to be primarily associated with the donating ability and the confor ma-tional energy barrier of the spacer ligands. Thermal analyses indicate that [Ag(CF3SO3)(3,3'-Py2O)] and [Ag(3,3'-Py2S)](CF3SO3) are stable up to 250 $^{\circ}C$ and 210 $^{\circ}C$, respectively. For the anion exchangeability, the nature of the spacer ligand is more significant factor than the distance of silver(Ⅰ)···triflate.

• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.990-996
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• 1994

New ferrocene-based chelate amines, $Fe[C_5H_4CH(Me)NMe_2]_2\;(3), \;Fe[C_5H-3(CH(Me)NMe_2)(PPh_2)-1,2]_2\;(4),\;(C_5H_5)Fe(C_5H_3(CH_2NMe_2)(CH(CN)NMe_2-1,2)\;(6),\;and\;(C_5H_5)Fe(C_5H_3(CH_2NMe_2)(CH(Me)NMe_2-1,2)$ (7) have been prepared. The reaction and the coordination chemistry of 4 and other related compounds (S,R)-(1-N,N-dimethylaminoethyl)-2-dicyclohexylphosphino)ferrocene (CPFA) and 1,1'-bis-(diphenylphosphino)ferrocene (BPPF) with $Rh_2(OAc)_4(MeOH)_2$ were investigated. The reaction of the chiral ligand (S,R)-CPFA forms a complex of the type (${\eta}^1$-(S,R)-CPFA-P)$_2Rh_2(OAc)_4$ (8) in which the ligand is coordinated to both rhodium centers in a monodentate fashion through phosphorus. In contrast, the bisphosphine analogues such as BPPF and 4 afford chelate complexes of the type (${\eta}^2-PP)Rh_2(OAc)_4$ (9 & 10) where both ligands act as a chelate bidentate to a single rhodium atom. All these complexes were characterized by microanalytical and spectroscopic techniques. In one case, the structure of 8 was determined by X-ray crystallography. Crystals are monoclinic, space group C2 (No. 5), with a=26.389 (3), b=12.942 (1), c=11.825 (1) A, ${\beta}$=111.22(1)$^{\circ}$, V=3964.7 (8) $A^3$, Z=4, and $D_{calc}$=1.58 g $cm^{-3}$. Two Rh(II) centers are bridged by four $AcO^-$ groups in the ${\eta}^1$ : ${\eta}^1$ mode across a Rh-Rh single bond, and octahedral coordination at Rh(1) and Rh(1') is completed by axially coordinating (S,R)-CPFA and a briding $AcO^-$, respectively.

• Analytical Science and Technology
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• v.21 no.6
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• pp.562-568
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• 2008

A novel two-dimensional cadmium(II)-nickel(II) bimetallic host clathrate, $[Cd{NH_2CH_2CH_2OH}_2Ni(CN)_4]{\cdot}3C_6H_5NH_2{\cdot}H_2O$, 1, has been synthesized and structurally characterized by X-ray single crystallographic method. The clathrate 1 crystallizes in the monoclinic system, space group $P2_1/c$ with a = 14.370(3), b = 7.728(1), c = 28.172(4) ${\AA}$, ${\beta}=97.58(1)^{\circ}$, V = 3101.1(9) ${\AA}^3$, Z = 4. The host framework of the clathrate 1 is built of the cyanide bridges between octahedral Cd(II) atom and square planar Ni(II) atom. The octahedral Cd atoms ligated by two 2-aminoethanol molecules and four cyanide ligands bridged with square planar Ni atoms. The Ni atoms bridges to four Cd atoms via cyanides is made up of puckered quadrangles of composition $\{CdNi(CN)_2\}_2$, all edges are shared. This cyanide bridges form an infinite two-dimensional host networks stacking along b axis. 2-Aminoethanol ligands bond to Cd atom through N atom as a monodentate ligand in the axial position and four cyanides take an equatorial plane with all in trans-configurations. The aniline guest molecules and water molecules are located in between the host layer sheets, respectively.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2774-2780
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• 2013

Two new isostructural dinuclear complexes, $Ln_2(4-cpa)_6(bpy)_2$ (Ln = Eu (1); Tb (2), 4-cpa = 4-chlorophenylacetate, bpy = 2,2'-bipyridine), have been hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction and single-crystal X-ray diffraction. The lanthanide ions are bridged by two bidentate and two terdentate carboxylate groups to give centrosymmetric dimers with $Ln{\cdots}Ln$ separations of 3.967(2) and 3.956(3) ${\AA}$, respectively. Each metal atom is nine-coordinate and exhibits a distorted tricapped trigonal prismatic geometry. Three-dimensional fluorescence spectra show that both 1 and 2 emit bright red and green luminescence at room temperature, with long lifetimes of up to 0.369 ms (at 614 nm) and 0.432 ms (at 543 nm), respectively. Moreover, poor luminescence efficiency has been noted for complex 2. The 4-Hcpa ligand and complexes 1-2 have been screened for their phytogrowth-inhibitory activities against Brassica napus L. and Echinochloa crusgalli L., and the results are compared with the activity of quizalofop-P-ethyl.

• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1257-1262
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• 2002

$[(C_2B_9H_{11})Mo(CO)_3]_2PPN_2$ $(2{\cdot}PPN_2)$, a new precursor for the oxidative decarbonylation reaction, was synthesized in high yield by the one-electron oxidation reaction of $[(C_2B_9H_{11})Mo(CO)_3]PPN_2$. $2{\cdot}PPN_2$ was structurally characterized, showing a dimeric nature with long (3.321 ${\AA}$) Mo-Mo bonding. Reaction of $2{\cdot}PPN_2$ with sulfur gave the completely decarbonylated product $[(C_2B_9H_{11})Mo({\mu}-S)(S)]_2PPN_2$ ($3{\cdot}PPN_2$). The ligand substitution of the terminal sulfur ligands in $3{\cdot}PPN_2$ to oxygen ligands was carried out with the use of PhIO to give $[(C_2B_9H_{11})Mo({\mu}-S)(O)]_2PPN_2$ ($4{\cdot}PPN_2$). The structures of $3{\cdot}PPN_2$ and $4{\cdot}PPN_2$ were also studied.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3255-3260
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• 2011

Two novel binuclear metal-organic coordination complexes $[Cd_2(L)_2(bpy)_2(H_2O)_2]{\cdot}6H_2O$ (1), $[Cd_2(L)_2(phen)_2-(H_2O)_2]{\cdot}2H_2O$ (2) (where L = 2-methylquinoline-3,4-dicarboxylate dianion, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline) have been synthesized under hydrothermal conditions and characterized by single crystal Xray diffraction, spectral method (IR), elemental analysis and thermal gravimetric analysis (TGA). Both 1 and 2 consist of two Cd(II) atoms bridged by two monoatomic bridging carboxylate groups from two L ligands, and the second carboxylate group of each L is monodentately coordinated to Cd(II), creating a sevenmembered chelating ring. The coordination at each metal nucleus is completed by a water molecule and a chelating bidentate molecule. The 3D structures of the complexes are stabilized by ${\pi}-{\pi}$ stacking interactions and hydrogen-bonds.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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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.