• Archives of Pharmacal Research
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• 제25권2호
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• pp.143-150
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• 2002

Fluorescent probes bound to DNA typically display nanosecond decay times and reveal only nanosecond motions. We extend the time range of measurable DNA dynamics using $[Ru(pby)_2(dppz)]^{2+}$ (bpy=2.2'-bipyridine, dppz=dipyrido[3,2-a2',3'-c]phenazine) (RuBD) which displays a mean lifetime near 90 ns. To test the usefulness of RuBD as a probe for diffusive processes in calf thymus DNA, we compared the efficiencies of fluorescence resonance energy transfer (FRET) using three donors which display lifetimes near 5 ns for acridine orange (AO), 22 ns for ethidum bromide (EB) and 92 ns for RuBD, with nile blue (NB) as the acceptor. The F rster distances for AO-NB, EB-NB and RuBD-NB donor-acceptor pairs were 42.3, 52.3, and $30.6{\;}{\AA}$, respectively. All three donors showed dramatic decreases in fluorescence intensities and more rapid intensity decays with increasing NB concentrations. The intensity decays of AO and EB in the presence of varying concentrations of NB were satisfactorily described by the one-dimensional FRET model without diffusion (Blumen and Manz, 1979). In the case of the long-lifetime donor RuBD, the experimental phase and modulation somewhat deviated from the recovered values computed from this model. The recovered NB concentrations and FRET efficiencies from the model were slightly larger than the expected values, however, the recovered and expected values did not show a significant difference. Thus, it is suggested that the lifetime of RuBD is too short to measure diffusive processes in calf thymus DNA.

• 대한화학회지
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• 제51권6호
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• pp.526-535
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• 2007

아다만탄 또는 β-cyclodextrin이 결합된 루테늄(II)-터피리딘 착화합물(8, 9, 11)을 합성하고 1H NMR, 13C NMR 및 질량분석스펙트럼으로 구조를 확인하였다. 아다만탄이 결합된 루테늄(II)-터피리딘 착화합물(8, 11) 은 물에 전혀 녹지 않으나, β-cyclodextrin 수용액에 혼합할 경우 β-cyclodextrin과의 초분자를 형성하여 물에 잘 녹아들어갔다. 비슷한 방법으로 수용액 중에서 루테늄(II)-터피리딘 착화합물(8, 11)을 각각 착화합물 9와 혼합 하였을 때, 착화합물(8, 11)의 아다만탄 부분이 루테늄 착화합물 9의 β-cyclodextrin 내부에 포접 됨으로써 안정 한 초분자를 형성하였다.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.325-334
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• 2018

Lactose is a reducing disaccharide consisting of two different monosaccharides such as galactose and glucose. The hydrogenation of lactose to lactitol is a formidable challenge because it is a complex process and several side products are formed. In this work, we synthesized Ru-Ni bimetallic nanohybrids as efficient catalysts for selective lactose hydrogenation to give selective lactitol. Ru-Ni bimetallic nanohybrids with $Ru-NiO_x$ (x = 1, 5, and 10 wt%) are prepared by impregnating Ru and Ni salts precursors with $TiO_2$ used as support material. Ru-Ni bimetallic nanohybrids (represented as $5Ru-5NiO/TiO_2$) catalyst is found to exhibit the remarkably high selectivity of lactitol (99.4%) and turnover frequency i.e. ($374h^{-1}$). In contrast, monometallic $Ru/TiO_2$ catalyst shows poor performance with ($TOF=251h^{-1}$). The detailed characterizations confirmed a strong interaction between Ru and NiO species, demonstrating a synergistic effect on the improvement on lactitol selectivity. The impregnation-reduction method for the preparation of bimetallic $Ru-NiO/TiO_2$ catalyst promoted Ru nanoparticles dispersed on NiO and intensified the interaction between Ru and NiO species. $Ru-NiO/TiO_2$ efficiently catalyzed the hydrogenation of lactose to lactitol with high yield/selectivity at almost complete conversion of lactose at $120^{\circ}C$ and 55 bar of hydrogen ($H_2$) pressure. Moreover, $Ru-NiO/TiO_2$ catalyst could also be easily recovered and reused up to four runs without notable change in original activity.

• Bulletin of the Korean Chemical Society
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• 제27권1호
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• pp.99-105
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• 2006

Polyamine dendrimers functionalized with electrochemiluminescent (ECL) polypyridyl Ru(II) complexes, dend-$[CO-(CH_2)_3-mbpy{\cdot}Ru(L)_2]_3(PF_6)_6$ (dend: N$(CH_2CH_2NH)_3$-, L: bpy, o-phen, phen-Cl, DTDP), were synthesized through the complexation of dendritic polypyridyl ligands to Ru(II) complexes. Their electrochemical redox potentials, photoluminescence (PL), and relative ECL intensities were studied. The ECL emissions produced by the reaction between the electro-oxidized $Ru^{3+}$ species of polyamine dendrimers and tripropylamine as a coreactant were measured in a static system with potential cycles between 0.8 and 1.3 V or through flow injection analysis with a potential of +1.3 V, and were compared to that of $[Ru(o-phen)_3](PF_6)_2{\cdot}Dend-[CO-(CH_2)_3-mbpy{\cdot}Ru(bpy)_2]_3(PF_6)_6$ showed an ECL intensity that was two-fold greater than that of the reference complex $[Ru(o-phen)_3](PF_6)_2$.

• Journal of the Korean Physical Society
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• 제73권11호
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• pp.1691-1697
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• 2018

Employing the density functional theory, we have investigated the roles of Coulomb and Hund's interactions in the electronic and magnetic properties of newly discovered ${\alpha}-RuCl_3$ having the $R{\overline{3}}$ symmetry, which is in close proximity of the Kitaev system. We show that both the size and the direction of local magnetic moment are highly dependent on Coulomb and Hund's interactions, and the spin and orbital parts show different behaviors. The validity of the so-called $j^{eff}$ picture is accessed upon interaction parameters, and the explicit roles of Hund's interaction in the local electronic structures and magnetic properties are discussed.

• 대한화학회지
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• 제37권1호
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• pp.98-104
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• 1993

$[({\eta}^5-C_5Me_5)RuCl_2]_2$ (1)과 1당량의 포스핀을 반응시켜 새로운 상자기성 루테늄(Ⅲ) 착물 $({\eta}^5-C_5Me_5)RuCl_2(PR_3) (PR_3 = PMe_3,\;PEt_3,\;PiPr_3,\;PCy_3,\;PMe_2Ph,\;PMePh_2,\;PPh_3,\;P(p-C_6H_4CH_3)_3$, DPPE, DPPB, Py) (2a∼2k)를 합성하였다. 자기화율의 측정으로 부터 얻어진 착물 (2a∼2k)의 유효자기모멘트값(${\mu}_{eff} = 1.65∼2.07 B.M.$)은 분자내 짝을 이루지 않는 전자가 1개 있는 전자배치의 경우와 일치하였다. 디클로로루테늄(Ⅲ) 착물 ({\eta}^5-C_5Me_5)RuCl_2(PR_3)$ (2) 는 (ⅰ)아세톤 용매 중에서 KBr과 반응하여 디브로모루테늄(Ⅲ) 착물 $({\eta}^5-C_5Me_5)RuBr_2(PR_3) (PR_3 = PPh_3)$로 전환되었고, (ⅱ) 디에틸에테르 용매 중에서 Na/Hg과 반응하여 비스(포스핀) 유도체 $({eta}^5-C_5Me_5)RuCl(PR_3)_2 (PR_3 = PMe_3,\;PMePh_2)$로 환원되었으며, (iii) CO와 반응하여 카르보닐 유도체$({\eta}^5-C_5Me_5)RuCl(PR_3)(CO) (PR_3 = PMe_3,\;PPh_3)$를 생성하였다.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.285-286
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• 2009

• Bulletin of the Korean Chemical Society
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• 제19권10호
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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.

• Rapid Communication in Photoscience
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• 제4권1호
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• pp.22-24
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• 2015

A new trinuclear complex $[Ru(TPrPc)(CO)]_2[Ru(pytpy)_2](PF_6)_2$ (TPrPc = 2,7,12,17-tetra-n-propylporphycenato dianion and pytpy = 4'-(4-pyridyl)-2,2':6',2"-terpyridine) has been synthesized and characterized as the first example of a discrete molecular wire containing metalloporohycenes as a building block. The trinuclear complex shows multiple-step redox behavior in 0.1 M n-$Bu_4NPF_6$-dichloromethane. The mononuclear $[Ru(pytpy)_2]^{2+}$ precursor shows emission at 640 nm (deaerated acetone, 298 K) upon illumination at the metal-to-ligand charge transfer (MLCT) band at 495 nm, but the trinuclear molecular wire is found to be non-emissive upon photoexcitation at the central $[Ru(pytpy)_2]^{2+}$ entity, indicating an efficient quenching ability of the axially-linked, ruthenium(II)-porphycene chromophores in an intramolecular fashion.

• Bulletin of the Korean Chemical Society
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• 제22권3호
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• pp.318-320
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• 2001