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- Sun, Shiguo, et al.
(författare)
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ECL performance of ruthenium tris-bipyridyl complexes covalently linked with phenothiazine through different bridge
- 2010
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 39:37, s. 8626-8630
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Tidskriftsartikel (refereegranskat)abstract
- Three ruthenium complexes 1a, 1b and 1c were synthesized, in which the phenothiazine moiety was covalently linked to the ruthenium complex through a 4 carbon chain and amide bond, respectively. The results demonstrate that one PTZ moiety is preferred to reach a good ECL performance, and the 4 carbon chain linked complex 1a exhibits the highest ECL enhancement (up to about 9 times), in comparison with the commonly utilized parent Ru(bpy)(3)(2+), permitting a lower detection limit of 1.0 x 10(-14) M with signal to noise of 3 for 20 mM DBAE at Au electrode.
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| 4. |
- Sun, Shiguo, et al.
(författare)
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Host-guest chemistry and light driven molecular lock of Ru(bpy)(3)-viologen with cucurbit 7-8 urils
- 2007
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 111:47, s. 13357-13363
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Tidskriftsartikel (refereegranskat)abstract
- Host-guest chemistry and photoinduced electron-transfer processes have been studied in the systems containing Ru(bPy)(3) complex covalently linked to viologen as a guest molecule and cucurbit[n]urils (n = 7, 8) as host molecules in aqueous solution. The Ru(bpy)(3)-viologen complex,[Ru(2,2 '-bipyridine)(2)(4-(4-(1 '-methyl-4,4 '-bipyridinediium-1-yl)butyl)-4 '-methyl-2,2 '-bipyridine)]Cl-4(denoted as RU2+-MV2+, 1) was shown to form stable 1:1 inclusion complexes with cucurbit[7]uril (CB[7]) and cucurbit[8] uril (CB[8]). The binding modes are slightly different with CB[7] and CB[8]. CB[7] preferentially binds to part of the viologen residue in 1 together with the butyl chain, whereas CB[8] preferentially encloses the whole viologen residue. Photoinduced intramolecular electron transfer from the excited-state of the Ru moiety to MV2+ which is inserted into the cavity of the CBs occurred. Long-lived charge-separated states RU3+-MV+center dot, were generated with the lifetimes of 280 ns with CB[7] and 2060 ns with CB[8]. This shows that CBs can slow down the charge recombination within supramolecular systems, and the difference in lifetimes seems to be due to the difference in binding modes. In the presence of a sacrificial electron donor triethanolarnine, light-driven formation of a dimer of MV+center dot inside the CB[8] cavity was observed. This locked molecular dimer can be unlocked by molecular oxygen to give back the original form of the molecular dyad 1 with the MV2+ moiety inserted in the cavity of CB[8]. The processes could be repeated several times and showed nice reversibility.
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| 5. |
- Sun, Shiguo, et al.
(författare)
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Intra- and intermolecular interaction ECL study of novel ruthenium tris-bipyridyl complexes with different amine reductants
- 2009
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; :38, s. 7969-7974
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Tidskriftsartikel (refereegranskat)abstract
- A series of ruthenium(II) tris-bipyridyl complexes covalently linked with different amine reductants such as tripropylamine (TPrA), ethanolamine and diethanolamine for an electrochemiluminescence (ECL) system have been synthesized. Their ECL property at different working electrodes has been studied with and without the presence of TPrA, triethanolamine (TEOA) and 2-(dibutylamino) ethanol (DBAE) as the coreactant, respectively. The results demonstrate that the conjugated ruthenium complex alone can generate ECL through intramolecular interaction at a relatively low concentration, while with intermolecular interaction the ECL intensity increases progressively and becomes increasingly dominant with increasing complex concentration. For the coreactant system ECL, the amine coreactant needed for the conjugate complexes can be significantly lowered in comparison with that of the well known [Ru(bpy)(3)](2+)/TPrA system. One amine substituent is better for the system in order to diminish the steric hindrance, and the intramolecular amine reductant employed should have a similar structure with that of the additive amine coreactant to achieve a good ECL performance, which can pave a new route to further improving the ECL efficiency and increase the sensitivity of detection through combining both intra-and intermolecular interaction.
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- Sun, Shiguo, et al.
(författare)
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Study of Highly Efficient Bimetallic Ruthenium Tris-bipyridyl ECL Labels for Coreactant System
- 2009
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 81:24, s. 10227-10231
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Tidskriftsartikel (refereegranskat)abstract
- A series of bimetallic ruthenium complexes [(bpy)(2)Ru(bpy)(CH2)(n)(bpy)Ru(bpy)(2)](4+) (1, where bpy is 2,2'-bipyridinyl, n = 3, 5, 8) for the coreactant electrochemiluminescence (ECL) system have been synthesized. Their ECL property at different working electrode has been studied in 0.1 M phosphate buffer by using tripropylamine (TPrA) and 2-(dibutylamino) ethanol (DBAE) as the coreactant. The results demonstrate that the ECL intensity depends largely on the length of the saturated carbon chain linkage: the longer is the carbon chain, the higher is the ECL intensity. A remarkable ECL enhancement (up to about 25 times), in comparison with the commonly used metallic [Ru(bpy)(3)](2+), has been observed from 1c (n = 8) at Pt electrode. With 20 mM TPrA, the log of the ECL intensity increases linearly with the log of complex 1c concentrations over the concentration range of 1.0 x 10(-16) to 1.0 x 10(-6) M at glassy carbon electrode. The detection limit is 1.0 x 10(-16) M at a signal-to-noise ratio of 3. This is the highest ECL detection limit for bimetallic system reported until now. The study provides a general methodology to further improve and tune the ECL efficiency by using multimetallic ruthenium complexes.
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- Sun, Shiguo, et al.
(författare)
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Synthesis and DNA photocleavage study of Ru(bpy)(3)(2+)-(CH2)(n)-MV2+ complexes
- 2010
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 39:18, s. 4411-4416
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Tidskriftsartikel (refereegranskat)abstract
- A series of Ru(bpy)(3)(2+)-(CH2)(n)-MV2+ complexes (1, n = 3, 4, 7) used for DNA photocleavage have been designed and synthesized. Under the irradiation of visible light, complexes 1 can cleave supercoiled plasmid DNA (pBR322) both in air and under Ar atmosphere. Radical species such as O2(-center dot), (OH)-O-center dot and the light-induced charge-separated (CS) oxidation state Ru(bpy)(3)(3+)-(CH2)(n)-MV+center dot are responsible for the cleavage. The longer the carbon chain linkage, the higher the DNA photocleavage efficiency. It is noted that backwards intramolecular electron transfer (ET) that exist in complexes 1 can lead to some decreasing effect on the cleavage result, while inclusion of complexes 1 with cucurbit[8]uril (CB[8]) inhibits the backwards ET to some extent, thereby increasing photocleavage efficiency.
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| 8. |
- Sun, Shiguo, et al.
(författare)
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Synthesis and ECL performance of highly efficient bimetallic ruthenium tris-bipyridyl complexes
- 2012
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 41:40, s. 12434-12438
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Tidskriftsartikel (refereegranskat)abstract
- In order to find the ideal carbon chain linkage number n for achieving the highest ECL in bimetallic ruthenium tris-bipyridyl complexes, a series of novel complexes [(bpy)(2)Ru(bpy')(CH2)(n)(bpy')Ru(bpy)(2)](4+) (1, where bpy is 2,2'-bipyridyl, n = 10, 12, 14) for a coreactant electrochemiluminescence (ECL) system have been synthesized. Their ECL properties at a Au electrode have been studied in 0.1 M phosphate buffer by using tripropylamine (TPrA), 2-(dibutylamino)ethanol (DBAE) and melamine as the coreactant, to compare with that of the previously reported bimetallic ruthenium analogous complex [(bpy)(2)Ru(bpy')(CH2)(8)(bpy')Ru(bpy)(2)](4+). The results demonstrate that the ECL intensity depends largely on the length of the saturated carbon chain linkage number n. The highest ECL is reached when n = 10, suggesting that a synergistic effect on ECL enhancement co-exists between the two intramolecular linked ruthenium activating centers. Density functional theory (DFT) calculation demonstrated that the optimized bond distances between Ru and N(bpy') are the longest both in the ground and the excited triplet states in the case of n = 10, while those for Ru and N(bpy) are the shortest in the excited triplet states. All these factors may be responsible for the above mentioned results. This study provided a methodology to further improve and tune ECL efficiency by using bimetallic ruthenium complexes linked by a flexible saturated carbon chain.
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