• Title/Summary/Keyword: 2,2':6':2''-Terpyridine

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Synthesis of 2,4,6-Tripyridyl Pyridines, and Evaluation of Their Antitumor Cytotoxicity, Topoisomerase I and II Inhibitory Activity, and Structure-activity Relationship

  • Jeong, Byeong-Seon;Choi, Ho-Young;Kwak, Young-Shin;Lee, Eung-Seok
    • Bulletin of the Korean Chemical Society
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    • v.32 no.10
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    • pp.3566-3570
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    • 2011
  • A series of 2,4,6-tripyridyl pyridines were synthesized, and evaluated for their antitumor cytotoxicity, topoisomerase I and II inhibitory activity. From the eighteen prepared compounds, compounds 10-12 have shown better or similar cytotoxicity against several human cancer cell lines as compared to 2,2':6',2"-terpyridine and doxorubicin. Especially, compound 10 exhibited the most potent cytotoxicity better than positive controls. Structure-activity relationship study indicated that 2,2':6',2"-terpyridine skeleton has an important role in displaying significant cytotoxicity against several human cancer cell lines.

Unidirectional Photo-induced Charge Separation and Thermal Charge Recombination of Cofacially Aligned Donor-Acceptor System Probed by Ultrafast Visible-Pump/Mid-IR-Probe Spectroscopy

  • Kim, Hyeong-Mook;Park, Jaeheung;Noh, Hee Chang;Lim, Manho;Chung, Young Keun;Kang, Youn K.
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.587-596
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    • 2014
  • A new ${\pi}$-stacked donor-acceptor (D-A) system, [Ru(1-([2,2'-bipyridine]-6-yl-methyl)-3-(2-cyclohexa-2',5'-diene-1,4-dionyl)-1H-imidazole)(2,2':6',2"-terpyridine)]$[PF_6]_2$ (ImQ_T), has been synthesized and characterized. Similar to its precedent, [Ru(6-(2-cyclohexa-2',5'-diene-1,4-dione)-2,2':6',2"-terpyridine)(2,2':6',2"-terpyridine)]$[PF_6]_2$ (TQ_T), this system has a cofacial alignment of terpyridine (tpy) ligand and quinonyl (Q) group, which facilitates an electron transfer through ${\pi}$-stacked manifold. Despite the presence of lowest-energy charge transfer transition from the Ru-based-HOMO-to-Q-based-LUMO (MQCT) predicted by theoretical calculations by using time-dependent density functional theory (TD-DFT), the experimental steady-state absorption spectrum does not exhibit such a band. The selective excitation to the Ru-based occupied orbitals-to-tpy-based virtual orbital MLCT state was thus possible, from which charge separation (CS) reaction occurred. The photo-induced CS and thermal charge recombination (CR) reactions were probed by using ultrafast visible-pump/mid-IR-probe (TrIR) spectroscopic method. Analysis of decay kinetics of Q and $Q^-$ state CO stretching modes as well as aromatic C=C stretching mode of tpy ligand gave time constants of <1 ps for CS, 1-3 ps for CR, and 10-20 ps for vibrational cooling processes. The electron transfer pathway was revealed to be Ru-tpy-Q rather than Ru-bpy-imidazol-Q.

Determination of Hg22+ Ions Using a Modified Glassy Carbon Electrode with 2,2':6':2''-Terpyridine

  • Kong, Young-Tae;Bae, Yun-Jung;Shim, Yoon-Bo
    • Bulletin of the Korean Chemical Society
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    • v.23 no.2
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    • pp.346-350
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    • 2002
  • A glassy carbon electrode (GCE) modified with 2,2':6':2”-terpyridine (2,2':6':2”-TPR) using a spin coating method was applied for the highly selective and sensitive analysis of a trace amount of $Hg_2^{2+}$ ions. Various experimental parameters, which influenced the response of the 2,2':6':2”-TPR modified electrode to $Hg_2^{2+}$ ions, were optimized. The linear sweep and differential pulse voltammograms for the 2,2':6':2”-TPR modified electrode deposited with Hg show a well-defined anodic peak at +0.65 V (vs. Ag|AgCl). After a 25 min preconcentration time in an $Hg_2^{2+}$ ion solution (0.1 M acetate buffer, pH 5.0), differential pulse voltammetry(DPV) with 2,2':6':2”-TPR modified electrode shows a linear response between $1.0\;{\times}\;10^{-6}M\;and\;2.0\;{\times}\;10^{-7}M$. The least-square treatment of these data produce an equation of I[${\mu}A$] = 0.031 + 0.005C with r = 0.980(n = 5). The detection limit of this electrode with linear sweep voltammetry and differential pulse anodic voltammetry were $2.0\;{\times}\;10^{-6}M\;and\;8.0\;{\times}\;10^{-8}M$, respectively. The presence of Pb, Fe, Cd, Ti, Ni, Co, Mg, Al, Mn, and Zn did not interfere in the analysis of the $Hg_2^{2+}$ ion. The 2,2':6':2”-TPR modified GCE has been successfully applied in determination trace amounts of Hg in a human urine sample.

Design. Synthesis and Antitumor Evaluation of Terpyridine Derivatives Containing Pyridines at 4'- Position

  • Lim, Hyun-Tae;Moon, Yoon-Soo;Zhao, Longxuan;Kim, Eun-Kyung;Kim, Tae-Hyung;Lee, Eung-Seok
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.347.3-347.3
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    • 2002
  • Recent study indicated that terpyridine and its derivatives displayed highly active antitumor properties. In this presentation. derivatives of terpyridines having three pyridine moieties at 2',4',6'-position of central pyridine skeleton were prepared, and evaluated their cytotoxicity against several human cancer cell lines and topoisomerase I inhibitory activities. Most of the prepared compounds showed strong cytotoxicity compared to doxorubicln. In addition. several compounds displayed better cytotoxicity than that of doxorubicin. In addition, several compounds displayed better cytotoxicity than that of doxorubicin. Structure-activity relationship study was perfomed to be indicated that [2.2':6',2']terpyidine skeleton is important to show strong xytotoxicity. Significant topoxicity. Significant topoisomerase I inhibitory activity was not observed for prepared compounds.

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Synthesis of 2,6-Diaromatic Substituted Pyridine Derivatives and Their Antitumor Activities

  • Moon, Yoon-Soo;Lim, Hyun-Tae;Zhao, Long-Xuan;Basnet-Arjun;Lee, Eung-Seok
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.345.1-345.1
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    • 2002
  • ${\alpha}$-terthienyl the first isolated from natural products shows potent antitumor activity, which encouraged us to study terpyridine and its biological properties. Terpyridine has also been reported as having carcinogenicity, and it's erivatives showed high cytotoxic activities against several human cancer cell lines and topoisomerase I inhibitory ctivity. Mannich free base from condensation reaction was allowed to react with pyridinum salts to give activity. (omitted)

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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.

Effect of Coordination Environment on the Photophysical Properties of Luminescent Europium(III) Complexes

  • Baek, Nam-Seob;Kim, Yong-Hee;Lee, Dong-Hyun;Seo, Kang-Deuk;Kim, Hwan-Kyu
    • Bulletin of the Korean Chemical Society
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    • v.30 no.7
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    • pp.1553-1558
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    • 2009
  • A series of Eu(III) complexes with various neutral ligands (2,2’:6’,2"-terpyridine (T), diglyme (D), 1N-(2-dimethylamino) ethyl)-1N, 2N, 2N-trimethylethane-1,2-diamine (PT), di-(2-picolyl)-amine derivative (HT), and multidentate terpyridine derivative (DT)) were synthesized to investigate the effect of coordination environment on the sensitized luminescence of Eu(III) complexes. The nine coordination sites of the $Eu^{3+}$ ion are occupied by three bidentate carboxylate moieties and one neutral ligand. The highest emission intensity is obtained for $Eu^{3+}$- $[NA]_3$ (PT), due to the difference in energy transfer efficiency and symmetry of the first coordination sphere of $Eu^{3+}$ ion. But, the lowest emission intensity is obtained for $Eu^{3+}$-$[NA]_3$(T). Terpyridine may not play an important role antenna for photosensitizing $Eu^{3+}$ ion. It could be attributed to the weak spectral overlap integral J value between its phosphorescence band and $Eu^{3+}$ion absorption band. Therefore, different coordination environment of $Ln^{3+}$ ion play an important role in providing sensitization of lanthanide ion emission.

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.