• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.747-750
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• 2006

Research on tripodal complexes has grown in recent decades and has been subject of numerous reports.1-11 The reasons for this interest include their relevance to model functions of metalloenzymes1-3 and their potential applications in catalysis.13-17 The ligand system used most in this category has been tren, the tripodal tetraamine N(CH2CH2NH2)3, and its derivatives.4 The bz3tren is a versatile tetradentate ligand, known to form stable complexes not only with transition metals5-11 including Cu2+, Zn2+ and Co2+ but also anion species.12 However, only few results on the d10 metal complexes with bz3tren have been reported by us10 and others.6,7 As a part of on going efforts, we therefore focus our attention to extend other d10 system that includes heavy metal ions.

• Bulletin of the Korean Chemical Society
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• v.18 no.4
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• pp.406-409
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• 1997

The various cobalt(Ⅱ) complexes were synthesized and characterized using tris-(2-benzimidazolylmethyl)amine (ntb) as a ligand where the ntb plays as a tripodal tetradentate ligand to form complexes with a trigonal pyramidal geometry. The complexes have 5 and 6 coordinate cobalt(Ⅱ) ions depending on the additional ligand used. In each complex the additional ligand, chloride anion, or acetate anion occupies the "open" site trans to the apical tertiary nitrogen atom of ntb ligand. Complex 1, [Co(Ⅱ)(ntb)Cl]Cl has a trigonal bipyramidal geometry. This geometry was easily constructed using ntb as a tetradentate ligand and chloride as a monodentate ligand. The complex is isostructural to the corresponding manganese(Ⅱ) complex. Crystal data are as follows: [Co(Ⅱ)(ntb)Cl]Cl·MeOH, 1. triclinic space group P1; a=13.524(2) Å, b=14.037(2) Å, c=17.275(1) Å; α=78.798(9), β=84.159(8)°, γ=65.504(9)°; V=2929.6(6) Å3; Z=4; R1=0.0715, wR2=0.1461 for reflections of I > 2σ(I). Six coordinate complex 2 [Co(ntb)(OAc)](OAc) was synthesized using ntb as a tetradentate ligand and acetate as a bidentate chelating ligand.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1597-1600
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• 2006

The mononuclear iron complex 1, $Fe^{III}$(Hbida)Cl($H_2O$), was synthesized using a tripodal tetradentate ligand, N-(benzimidazol-2-ylmethyl)iminodiacetic acid (H3bida), which has two carboxylate groups, one benzimida- zoyl group, and one tertiary amine where it serves as a tetradentate chelating ligand for the octahedral Fe(III) ion. The four equatorial positions of the octahedral complex are occupied by two monodentate carboxylates, a benzimidazole nitrogen, and an oxygen of a water molecule. One of the axial positions is occupied by an apical nitrogen of the Hbida and the other by a chloride anion. The mononuclear octahedral complex 1 mimics the geometry of the key intermediate structure of the catalytic reaction cycle proposed for the FeSODs, which is a distorted octahedral geometry with three histidyl imidazoles, an aspartyl carboxylate, a superoxide anion, and a water molecule. The redox potential of complex 1, $E_{1/2}$ is -0.11V vs. Ag/AgCl (0.12 V vs. NHE), which is slightly lower than those reported for the most FeSODs. The magnetic susceptibility of complex 1 at room temperature is 5.83 $\mu$B which is close to that of the spin only value, 5.92 $\mu$B of high-spin d5 Fe(III).

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2546-2548
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• 2007

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.3904-3908
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• 2011

A new octahedral Ru(III) complex with a tripodal tetraamine ligand, tpea = tris[2-(1-pyrazoyl)ethyl]amine, has been prepared and characterized. The single crystal X-ray crystallographic study of the complex revealed that the complex has a near octahedral geometry with the tetradentate ligand and two chloride ions. Peroxidase activity was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of the complex. Amount of $ABTS^{+{\bullet}}$ generated during the reaction was monitored by UV/VIS and EPR spectroscopies. After the initiation of the peroxidase reaction, $ABTS^{+{\bullet}}$ concentration increases and then decreases after certain time, indicating that both ABTS and $ABTS^{+{\bullet}}$ are the substrates of the peroxidase activity of the Ru(III) complex.

• Bulletin of the Korean Chemical Society
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• v.20 no.10
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• pp.1235-1237
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• 1999

• Bulletin of the Korean Chemical Society
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• v.21 no.1
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• pp.65-68
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• 2000

A $\mu-oxo$ diiron(III) complex and two bis( $\mu-alkoxo)$ diiron(III) complexes with biomimetic tripodal ligand containing mixed N/O donor atoms were synthesized using a mononuclear iron(III) complex as starting material. Depending on the amounts and kinds of bases used, we obtained various kinds of diiron (III) complexes. The reaction of $[$Fe^{III}$(Hbbea)Cl_2]Cl$, 1, with an equivalent amount of $KO_2$ or NaOAc produced $[$Fe^{III}$_2O(Hb-bea)_2Cl_2]Cl_2$, 2. An additional equivalent amount of NaOBz or NaOAc converts complex 2 to complex 3 or complex 4 depending on the base used. The addition of two equivalent amounts of NaOBz orNaOAc directly converts complex 1 to $[$Fe^{III}$_2(bbea)_2(OBz)_2]Cl_2$, 3, or $[$Fe^{III}$_2(bbea)_2(OAc)_2]Cl_2$, 4, depending on the base used. Crystal data are as follows: [$Fe^{III}_2O(Hbbea)_2Cl_2]Cl_2$, 2: monoclinic space group $$P2_1/n$$, a = 8.421 (1) $\AA$, b = 18.416 (2) $\AA$, c = 13.736 (1) $\AA$, $\beta$ = 104.870 $(7)^{\circ}$, V = 2058.9 (4) $\AA^3$, Z = 2, R1 = 0.0469 and wR2 = 0.1201 for reflections with I > 2 ${\sigma}$(I).

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.1956-1962
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• 2009

The binding abilities of two multidentate tripodal amine catechol ligands, cis,cis-1,3,5-tris[(2,3-dihydroxybenzylamino) aminomethyl]cyclohexane (TMACHCAT, $L^1)\;and\;N^1,N^3,N^5$-tris(2-(2,3-dihydroxybenzylamino) ethyl)cyclohexane-1,3,5-tricarboxamide (CYCOENCAT, $L^2$) with Ga(III) and In(III) have been investigated by potentiometric and spectrophotometric methods in an aqueous medium of 0.1 M KCl at 25 ${\pm}\;1\;{^{\circ}C}.$ The ligands $L^1\;and\;L^2$ formed various monomeric species $MLH_3,\;MLH_2$, MLH and ML (M = $Ga^{+3}\;and\;In^{+3}$) and showed potential to form strong encapsulated tris(catechol) type complexes. The coordination modes, binding ability and selectivity of the ligands towards Ga(III) and In(III) have been discussed with the help of experimental evidences, and supported with molecular modeling calculations.

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.417-420
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• 2007

Mononuclear mixed-anions Mn complex of TPAMn(η2-NO3)(η-ClO4), where TPA is tris(2-pyridylmethyl)-amine, has been synthesized and characterized. The neutral TPAMn(η2-NO3)(η-ClO4) was obtained from the reaction between Mn(NO3)2·4H2O and [H3TPA](ClO4)3 in MeOH. X-ray crystallographic structure of mononuclear TPAMn(η2-NO3)(η-ClO4) complex showed a seven-coordinated geometry with a tripodal tetradentate TPA, a terminal perchlorate and an η2-bound nitrate.

• Journal of the Korean Chemical Society
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• v.51 no.1
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• pp.31-35
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• 2007

The tripodal copper(II) complex [Cu(pmea)(H2O)](ClO4)2·H2O (1) (pmea = bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine) has been synthesized and structurally characterized by X-ray diffraction method. It crystallizes in the triclinic system P-1 with a = 9.9362(9), b = 15.7299(17), c = 18.0562(11) A, α = 68.760(8), β = 76.331(6), γ = 77.092(9)°, V = 2526.2(4) A3, Z = 2. Each copper atom reveals a distorted square pyramidal with three nitrogen atoms of the pmea ligand and water molecule occupying the basal plane and one nitrogen atom from the pyridine ring according the axial position. The cyclic voltammogram of 1 undergoes reversible one-electron oxidation to the CuIII and reversible one-electron reduction to the CuI.