• Title/Summary/Keyword: Terpyridine

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Reaction of Ru(tpy)$Cl_3$ with N,N,C-Terdentates, 3,2'-Annulated-6-(2"-pyridyl)-2-phenylpyridines

  • 장영동;박재규
    • Bulletin of the Korean Chemical Society
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    • v.20 no.10
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    • pp.1200-1204
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    • 1999
  • The reactions of Ru(tpy)Cl3 (tpy = 2,2';6',2"-terpyridine) with new N,N,C-terdentate ligands, 3,2'-annulated-6-(2"-pyridyl)-2-phenylpyridines (1, HL) and the properties of their Ru(II) complexes are described. The distribution ratio of the two possible Ru(II) complexes, a pentaaza-coordinated complex [Ru(tpy)(1-N,N')Cl]+ and a cycloruthenated complex [Ru(tpy)(La-N,N',C)]+ are highly dependent on the length of the polymethylene unit. The trimethylene bridge of the N,N,C-terdentate in pentaaza-coordinated complex is rigid enough to induce an asymmetry in the complex.

NMR Study on Ru(II) Complexes Containnig 2,$2^{\prime} :\;6^{\prime},2^{\prime}^{\prime}$-terpyridine

  • Seok, Won K.;Moon, Sung W.;Kim, Mee Y.
    • Bulletin of the Korean Chemical Society
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    • v.19 no.11
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    • pp.1207-1210
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    • 1998
  • The diamagnetic six-coordinate ruthenium polypyridyl complexes have been prepared and assigned. 1H NMR spectral studies were used to unravel the ligand field strength and the basicity on the chemical shift to the particular proton of ligand L in [(tpy)(L)RuⅡ(X)]+/2+ (L=bpy, bqi, dmbpy, phen; X=Cl, CN, N3, NCCD3, NO2, SCN) complexes.

Synthesis and Properties of Terdentates with Extra Pyridine Ring and Their Ru(II) Complexes

  • 장영동;문승욱;Randolph P. Thummel
    • Bulletin of the Korean Chemical Society
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    • v.18 no.2
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    • pp.174-179
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    • 1997
  • The synthesis and electronic as well as redox properties of four Ru(Ⅱ) complexes based on the ligand 4'-(4-pyridyl)-3,3';5',3"-bis-dimethylene-2,2';6',2"-terpyridine are reported. Each new complex is of the type [Ru(L)2]n+ and [Ru(tpy)(L)]n+, where L is the terdentate ligand with extra pyridine ring at 4'-position or is a N-methylated ligand and n=2, 3, or 4. Cyclic voltammetry indicates that the first electron added to the complex enters the viologen-type acceptor in N-methylated ligand.

Comparison of the Binding Modes of [Ru(2,2'-bipyridine)3]2+ and [Ru(2,2':6',2"-terpyridine)2]2+ to Native DNA

  • Jang, Yoon-Jung;Lee, Hyun-Mee;Jang, Kyeung-Joo;Lee, Jae-Cheol;Kim, Seog-K.;Cho, Tae-Sub
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1314-1318
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    • 2010
  • The $[Ru(tpy)_2]Cl_2$ (tpy:2,2':6',2"-terpyridine) complex was synthesized and its structure was confirmed by $^1H$-NMR and elemental analysis. Its binding mode toward DNA was compared with the well-known $[Ru(bpy)_3]Cl_2$ (bpy:2,2-bipyridyl), using isotropic absorption, linear dichroism(LD) spectroscopy, and an energy minimization study. Compared to $[Ru(bpy)_3]^{2+}$, the $[Ru(tpy)_2]^{2+}$ complex exhibited very little change in its absorption pattern, especially in the MLCT band, upon binding to DNA. Furthermore, upon DNA binding, both Ru(II) complexes induced a decrease in the LD magnitude in the DNA absorption region. The $[Ru(tpy)_2]^{2+}$ complex produced a strong positive LD signal in the ligand absorption region, which is in contrast with the $[Ru(bpy)_3]^{2+}$ complex. Observed spectral properties led to the conclusion that the interaction between the ligands and DNA bases is negligible for the $[Ru(tpy)_2]^{2+}$ complex, although it formed an adduct with DNA. This conclusion implies that both complexes bind to the surface of DNA, most likely to negatively charged phosphate groups via a simple electrostatic interaction, thereby orienting to exhibit the LD signal. The energy minimization calculation also supported this conclusion.

Oxidation of Benzyl Alcohols with Extraordinarily High Kinetic Isotope Effects

  • Jo, Myeong-Ran;Seok, Won-K.
    • Bulletin of the Korean Chemical Society
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    • v.32 no.spc8
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    • pp.3003-3008
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    • 2011
  • Reactions of benzyl alcohol and its derivatives by [Ru$^{IV}$(tpy)(dcbpy)(O)]$^{2+}$ (tpy = 2,2':6',2"-terpyridine; dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) leading to the corresponding benzaldehydes in acetonitrile and water have been studied. Kinetic studies show that the reaction is first-order in both alcohol and oxidant, with k = 1.65 (${\pm}$ 0.1) $M^{-1}s^{-1}$ at $20^{\circ}C$, ${\Delta}H^{\ddag}$ = 4.3 (${\pm}$ 0.1) kcal/mol, ${\Delta}S^{\ddag}$ = -22 (${\pm}$ 1) eu, and $E_a$ = 4.9 (${\pm}$ 0.1) kcal/mol. High ${\alpha}$ C-H kinetic isotope effects are observed, but O-H solvent isotope effects are negligible. Spectral evidences with the isotope effects suggest that oxidation of benzyl alcohols occurs by a two-electron, hydride transfer. The catalytic cycles of aerobic benzyl alcohol oxidation are employed.

Synthesis, Cytotoxicity and Structure-Activity Relationship Study of Terpyridines

  • Zhao, Long-Xuan;Sherchan, Jyoti;Park, Jung-Ki;Jahng, Yurng-Dong;Jeong, Byeong-Seon;Jeong, Tae-Cheon;Lee, Chong-Soon;Lee, Eung-Seok
    • Archives of Pharmacal Research
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    • v.29 no.12
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    • pp.1091-1095
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    • 2006
  • For the development of novel antitumor agents, we designed and synthesized terpyridines, and their biological activities were evaluated. Although most of the newly prepared terpyridines showed strong cytotoxicity against several human cancer cell lines, [2,2';6',2"]-terpyridine displayed the most significant cytotoxicity.

Synthesis and Characterization of Volatile and Thermally Stable Europium β-Diketonate Complexes

  • 강성주;정영숙
    • Bulletin of the Korean Chemical Society
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    • v.18 no.1
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    • pp.75-80
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    • 1997
  • Preparation and properties of Eu(hfa)3·L (Hhfa = hexafluoroacetylacetone, L = bis(2-methoxyethyl)ether, diglyme, and 2, 2':6', 2"-terpyridine, tpy), which are potential CVD precursors for europium, were investigated. The reaction of the Eu2O3 with Hhfa in the presence of tridentate neutral ligand yielded the nine-coordinated Eu(hfa)3·L. Eu(hfa)3·diglyme is air- and moisture-stable and most importantly has good volatility and thermal stability. Eu(hfa)3·tpy shows no sublime intact. The complex Eu(hfa)3·diglyme has been characterized by an X-ray structure determination; monoclinic P21/n, a=10.252(1), b=16.051(6), c=19.392(8) Å, β=96.10(2)°, V=3173(2) Å3. The europium atom in Eu(hfa)3·diglyme adopts a square-antiprismatic geometry with the ninth coordinating oxygen atom capping one of the square faces. All the adducts have been characterized by IR, TGA/DTA.

The Comparative Study in the Oxygen Atom Transfer Reaction by Ruthenium Mono-Oxo Complexes

  • Seok, Won K.;Son, Yung J.;Moon, Sung W.;Lee, Heung N.
    • Bulletin of the Korean Chemical Society
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    • v.19 no.10
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    • pp.1084-1090
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    • 1998
  • The oxidation of triphenylphosphine by [(tpy)(phen)RuⅣ(O)]2+ and [(bpy)(p-tert-butylpy)RuⅣ(0)]2+ (tpy is 2,2': 6',2"-terpyridine, phen is 1,10-phenanthroline, bpy is 2,2'-bipyridine, and p-tert-butylpy is para-tertbutylpyridine) in CH3CN has been studied. Experiments using 18O-labeled complex show the oxyl group transfer from [RuⅣ=O]2+ to triphenylphosphine occured quantitatively within experimental error. Kinetic data were fit to a second-order for [RuⅣ=O]2+ and [PPh3]. The initial product, [RuⅡ-OPPh3]2+, was formed as an observable intermediate and then underwent slow solvolysis. The reaction proceeded as endothermic in activation enthalpy and a decrease in activation entropy. The oxidative reactivity of four representative ruthenium mono-oxo oxidants against triphenylphosphine was compared. These systems have been utilized as electrochemical oxidative catalysts.

Mechanistic Studies on the Oxidation of Triphenylphosphine by $[(tpy)(bpy)Ru^{IV}=O]^{2+}$, Structure of the Parent Complex $[(tpy)(bpy)Ru^{II}-OH_2]^{2+}$

  • 석원경;김미영;Yoshinobu Yokomori;Derek J. Hodgson;Thomas J. Meyer
    • Bulletin of the Korean Chemical Society
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    • v.16 no.7
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    • pp.619-624
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    • 1995
  • Oxidation of triphenylphosphine to triphenylphosphine oxide by [(tpy)(bpy)Ru(O)]2+ (tpy is 2,2':6',2"-terpyridine and bpy is 2,2'-bipyridine) in CH3CN has been studied. Experiments with the 18O-labeled oxo complex show that transfer of oxygen from [(tpy)(bpy)RuⅣ=O]2+ to triphenylphosphine is quantitative within experimental error. The reaction is first order in each reactant with k (25.3 ℃)=1.25 × 106 M-1s-1. The inital product, [(tpy)(bpy)RuⅡ-OPPh3]2+, is formed as an observable intermediate and undergoes slow k (25 ℃)=6.7 × 10-5 s-1 solvolysis. Activation parameters for the oxidation step are ΔH≠=3.5 kcal/mol and ΔS≠=-23 eu. The geometry at ruthenium in the complex cation, [(tpy)(bpy)RuⅡ(OH2)]2+, is approximately octahedral with the ligating atoms being the three N atoms of the tpy ligand, the two N atoms of the bpy ligand, and the oxygen atom of the aqua ligand. The Ru-O bond length is 2.136(5) Å.

Ruthenium Complex-catalyzed Highly Selective Co-oligomerization of Alkenes

  • Ura, Yasuyuki;Tsujita, Hiroshi;Mitsudo, Take-Aki;Kondo, Teruyuki
    • Bulletin of the Korean Chemical Society
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    • v.28 no.12
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    • pp.2139-2152
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    • 2007
  • Ruthenium complex-catalyzed reactions often require highly qualified tuning of reaction conditions with substrates to attain high yield and selectivity of the products. In this review, our strategies for achieving characteristic ruthenium complex-catalyzed co-oligomerization of different alkenes are disclosed: 1) The codimerization of 2-norbornenes with acrylic compounds by new ruthenium catalyst systems of RuCl3(tpy)/Zn [tpy = 2,2':6',2''-terpyridine] or [RuCl2(η6-C6H6)]2/Zn in alcohols, 2) A novel synthesis of 2-alkylidenetetrahydrofurans from dihydrofurans and acrylates by zerovalent ruthenium catalysts, such as Ru(η4-cod)(η6-cot) [cod = 1,5-cyclooctadiene, cot = 1,3,5-cyclooctatriene] and Ru(η6-cot)(η2-dmfm)2 [dmfm = dimethyl fumarate], 3) Regio- and stereoselective synthesis of enamides by Ru(η6-cot)(η2-dmfm)2-catalyzed codimerization of N-vinylamides with alkenes, and 4) Unusual head-to-head dimerization of styrenes and linear codimerization of styrenes with ethylene by Ru(η6-cot)(η2-dmfm)2 catalyst in the presence of primary alcohols.