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Back Cover: Enhanced Electrochemiluminescence from a Stoichiometric Ruthenium(II)–Iridium(III) Complex Soft Salt (Chem. Eur. J. 20/2015) 下载免费PDF全文
Dr. Kalen N. Swanick Dr. Martina Sandroni Prof. Dr. Zhifeng Ding Prof. Dr. Eli Zysman‐Colman 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(20):7624-7624
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Tuning the Cellular Uptake Properties of Luminescent Heterobimetallic Iridium(III)–Ruthenium(II) DNA Imaging Probes 下载免费PDF全文
Dr. Ashley Wragg Dr. Martin R. Gill Dr. David Turton Harry Adams Thomas M. Roseveare Prof. Carl Smythe Dr. Xiaodi Su Dr. Jim A. Thomas 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(43):14004-14011
The synthesis of two new luminescent dinuclear IrIII–RuII complexes containing tetrapyrido[3,2‐a:2′,3′‐c:3′′,2′′‐h:2′′′,3′′′‐j]phenazine (tpphz) as the bridging ligand is reported. Unlike many other complexes incorporating cyclometalated IrIII moieties, these complexes display good water solubility, allowing the first cell‐based study on IrIII–RuII bioprobes to be carried out. Photophysical studies indicate that emission from each complex is from a RuII excited state and both complexes display significant in vitro DNA‐binding affinities. Cellular studies show that each complex is rapidly internalised by HeLa cells, in which they function as luminescent nuclear DNA‐imaging agents for confocal microscopy. Furthermore, the uptake and nuclear targeting properties of the complex incorporating cyclometalating 2‐(4‐fluorophenyl)pyridine ligands around its IrIII centre is enhanced in comparison to the non‐fluorinated analogue, indicating that fluorination may provide a route to promote cell uptake of transition‐metal bioprobes. 相似文献
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Enhanced Iridium Complex Electrochemiluminescence Cytosensing and Dynamic Evaluation of Cell‐Surface Carbohydrate Expression 下载免费PDF全文
Dr. Hong Zhou Yiying Yang Chunxiang Li Bing Yu Prof. Dr. Shusheng Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(45):14736-14743
A newly prepared [(ppy)2Ir(dcbpy)]+?PF6? (ppy: 2‐phenylpyridyl; dcbpy: 4,4′‐dicarboxy‐2,2′‐bipyridyl) and gold nanoparticle functionalized mesoporous silica nanoparticle (Au/Ir‐MSN) is reported. Based on the binding between concanavalin A (Con A) and mannose, the novel nanoparticle was applied to an ultrasensitive electrochemiluminescence (ECL) in situ cytosensing strategy and the dynamic evaluation of cell‐surface carbohydrate expression. The ECL activity of the presented Con A@Au/Ir‐MSN nanoprobe was greatly enhanced by employing a functionalized nanoparticle and graphene nanomaterial with an increased surface area and simultaneously improved electron‐transfer efficiency at the electrode interface. Under optimal conditions, the sandwich‐type ECL cytosensor showed a linear response to K562 cells at concentrations ranging from 1.0×102 to 1.0×106 cells mL?1 and realized a low detection limit of a single cell. The proposed method could also be successfully used for monitoring the dynamic variation of carbohydrate expression in cancer cells in response to external stimulation by an inhibitor. 相似文献
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Marcus Schulze Dr. Andreas Steffen Prof. Dr. Frank Würthner 《Angewandte Chemie (International ed. in English)》2015,54(5):1570-1573
The phosphorescence emission of perylene bisimide derivatives has been rarely reported. Two novel ruthenium(II) and iridium(III) complexes of an azabenz‐annulated perylene bisimide (ab‐PBI), [Ru(bpy)2(ab‐PBI)][PF6]2 1 and [Cp*Ir(ab‐PBI)Cl]PF6 2 are now presented that both show NIR phosphorescence between 750–1000 nm in solution at room temperature. For an NIR emitter, the ruthenium complex 1 displays an unusually high quantum yield (Φp) of 11 % with a lifetime (τp) of 4.2 μs, while iridium complex 2 exhibits Φp<1 % and τp=33 μs. 1 and 2 are the first PBI‐metal complexes in which the spin–orbit coupling is strong enough to facilitate not only the Sn→Tn intersystem crossing of the PBI dye, but also the radiative T1→S0 transition, that is, phosphorescence. 相似文献
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Yoshihiro Shimoyama Dr. Tomoya Ishizuka Dr. Hiroaki Kotani Prof. Dr. Yoshihito Shiota Prof. Dr. Kazunari Yoshizawa Dr. Kaoru Mieda Prof. Dr. Takashi Ogura Dr. Toshihiro Okajima Prof. Dr. Shunsuke Nozawa Prof. Dr. Takahiko Kojima 《Angewandte Chemie (International ed. in English)》2016,55(45):14041-14045
Proton‐coupled electron‐transfer oxidation of a RuII?OH2 complex, having an N‐heterocyclic carbene ligand, gives a RuIII?O. species, which has an electronically equivalent structure of the RuIV=O species, in an acidic aqueous solution. The RuIII?O. complex was characterized by spectroscopic methods and DFT calculations. The oxidation state of the Ru center was shown to be close to +3; the Ru?O bond showed a lower‐energy Raman scattering at 732 cm?1 and the Ru?O bond length was estimated to be 1.77(1) Å. The RuIII?O. complex exhibits high reactivity in substrate oxidation under catalytic conditions; particularly, benzaldehyde and the derivatives are oxidized to the corresponding benzoic acid through C?H abstraction from the formyl group by the RuIII?O. complex bearing a strong radical character as the active species. 相似文献
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Emanuela Berni Dr. Isabelle Gosse Dr. Denis Badocco Dr. Paolo Pastore Prof. Neso Sojic Prof. Sandra Pinet Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(20):5145-5152
Different lights, different selectivies : Luminescence of a new guanidinium 3,3′‐functionalized bipyridyl–RuII complex has been studied for sensing of several anions. L ‐Glutamate and dihydrogenphosphate are both detected by photoluminescence and electrochemiluminescence. However, the complex displays differential selectivities for these anions depending on the sensing channels (see scheme).
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Understanding Electrogenerated Chemiluminescence Efficiency in Blue‐Shifted Iridium(III)‐Complexes: An Experimental and Theoretical Study 下载免费PDF全文
Dr. Gregory J. Barbante Dr. Egan H. Doeven Emily Kerr Timothy U. Connell Dr. Paul S. Donnelly Prof. Jonathan M. White Thais Lópes Sarah Laird Dr. David J. D. Wilson Dr. Peter J. Barnard Dr. Conor F. Hogan Prof. Paul S. Francis 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(12):3322-3332
Compared to tris(2‐phenylpyridine)iridium(III) ([Ir(ppy)3]), iridium(III) complexes containing difluorophenylpyridine (df‐ppy) and/or an ancillary triazolylpyridine ligand [3‐phenyl‐1,2,4‐triazol‐5‐ylpyridinato (ptp) or 1‐benzyl‐1,2,3‐triazol‐4‐ylpyridine (ptb)] exhibit considerable hypsochromic shifts (ca. 25–60 nm), due to the significant stabilising effect of these ligands on the HOMO energy, whilst having relatively little effect on the LUMO. Despite their lower photoluminescence quantum yields compared with [Ir(ppy)3] and [Ir(df‐ppy)3], the iridium(III) complexes containing triazolylpyridine ligands gave greater electrogenerated chemiluminescence (ECL) intensities (using tri‐n‐propylamine (TPA) as a co‐reactant), which can in part be ascribed to the more energetically favourable reactions of the oxidised complex (M+) with both TPA and its neutral radical oxidation product. The calculated iridium(III) complex LUMO energies were shown to be a good predictor of the corresponding M+ LUMO energies, and both HOMO and LUMO levels are related to ECL efficiency. The theoretical and experimental data together show that the best strategy for the design of efficient new blue‐shifted electrochemiluminophores is to aim to stabilise the HOMO, while only moderately stabilising the LUMO, thereby increasing the energy gap but ensuring favourable thermodynamics and kinetics for the ECL reaction. Of the iridium(III) complexes examined, [Ir(df‐ppy)2(ptb)]+ was most attractive as a blue‐emitter for ECL detection, featuring a large hypsochromic shift (λmax=454 and 484 nm), superior co‐reactant ECL intensity than the archetypal homoleptic green and blue emitters: [Ir(ppy)3] and [Ir(df‐ppy)3] (by over 16‐fold and threefold, respectively), and greater solubility in polar solvents. 相似文献
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Dr. Daniel Escudero Eike Heuser Dr. Robert J. Meier Priv.‐Doz. Dr. Michael Schäferling Prof. Dr. Walter Thiel Prof. Dr. Elisabeth Holder 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(46):15639-15644
We report the synthesis and characterization of a neutral heteroleptic IrIII complex bearing 6‐fluoro‐2‐phenylbenzo[d]thiazole as cyclometalating ligand and (Z)‐6‐(9H‐carbazol‐9‐yl)‐5‐hydroxy‐2,2‐dimethylhex‐4‐en‐3‐one as ancillary ligand. The photodeactivation mechanisms have been elucidated through extensive density functional theory (DFT) calculations. The active role of metal‐centered (3MC) triplet excited states in the nonradiative deactivation pathways is, for first time, confirmed in such complexes. 相似文献
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以4-甲氧羰基-2-苯基喹啉为环金属配体,N^N辅助配体为解离配体合成了一系列离子型环金属铱配合物.配合物的结构通过质谱、核磁进行了表征.配合物1还测试了其单晶结构.对配合物的紫外、磷光性质进行了表征,溶液状态下为红光发射,波长在610~620 nm之间,磷光寿命在133~496 ns之间,量子效率在0.7%~16.6%之间.铱配合物的电化学发光与23Ru(bpy)+有所不同,发光电位比23Ru(bpy)+要高,且大部分铱配合物在正负电位都能发光,最大发光强度是23Ru(bpy)+的三倍. 相似文献
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Transformation of a Cp*–Iridium(III) Precatalyst for Water Oxidation when Exposed to Oxidative Stress 下载免费PDF全文
Dr. Cristiano Zuccaccia Prof. Gianfranco Bellachioma Prof. Olga Bortolini Alberto Bucci Arianna Savini Prof. Dr. Alceo Macchioni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(12):3446-3456
The reaction of [Cp*Ir(bzpy)NO3] ( 1 ; bzpy=2‐benzoylpyridine, Cp*=pentamethylcyclopentadienyl anion), a competent water‐oxidation catalyst, with several oxidants (H2O2, NaIO4, cerium ammonium nitrate (CAN)) was studied to intercept and characterize possible intermediates of the oxidative transformation. NMR spectroscopy and ESI‐MS techniques provided evidence for the formation of many species that all had the intact Ir–bzpy moiety and a gradually more oxidized Cp* ligand. Initially, an oxygen atom is trapped in between two carbon atoms of Cp* and iridium, which gives an oxygen–Ir coordinated epoxide, whereas the remaining three carbon atoms of Cp* are involved in a η3 interaction with iridium ( 2 a ). Formal addition of H2O to 2 a or H2O2 to 1 leads to 2 b , in which a double MeCOH functionalization of Cp* is present with one MeCOH engaged in an interaction with iridium. The structure of 2 b was unambiguously determined in the solid state and in solution by X‐ray single‐crystal diffractometry and advanced NMR spectroscopic techniques, respectively. Further oxidation led to the opening of Cp* and transformation of the diol into a diketone with one carbonyl coordinated at the metal ( 2 c ). A η3 interaction between the three non‐oxygenated carbons of “ex‐Cp*” and iridium is also present in both 2 b and 2 c . Isolated 2 b and mixtures of 2 a – c species were tested in water‐oxidation catalysis by using CAN as sacrificial oxidant. They showed substantially the same activity than 1 (turnover frequency values ranged from 9 to 14 min?1). 相似文献
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Thomas Cruchter Dr. Klaus Harms Prof. Dr. Eric Meggers 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(49):16682-16689
The reactivity of an exemplary ruthenium(II)–azido complex towards non‐activated, electron‐deficient, and towards strain‐activated alkynes at room temperature and low millimolar azide and alkyne concentrations has been investigated. Non‐activated terminal and internal alkynes failed to react under such conditions, even under copper(I) catalysis conditions. In contrast, as expected, rapid cycloaddition was observed with electron‐deficient dimethyl acetylenedicarboxylate (DMAD) as the dipolarophile. Since DMAD and related propargylic esters are excellent Michael acceptors and thus unsuitable for biological applications, we investigated the reactivity of the azido complex towards cycloaddition with derivatives of cyclooctyne (OCT), bicyclo[6.1.0]non‐4‐yne (BCN), and azadibenzocyclooctyne (ADIBO). While no reaction could be observed in the case of the less strained cyclooctyne OCT, the highly strained cyclooctynes BCN and ADIBO readily reacted with the azido complex, providing the corresponding stable triazolato complexes, which were amenable to purification by conventional silica gel column chromatography. An X‐ray crystal structure of an ADIBO cycloadduct was obtained and verified that the formed 1,2,3‐triazolato ligand coordinates the metal center through the central N2 atom. Importantly, the determined second‐order rate constant for the ADIBO cycloaddition with the azido complex (k2=6.9 × 10?2 M ?1 s?1) is comparable to the rate determined for the ADIBO cycloaddition with organic benzyl azide (k2=4.0 × 10?1 M ?1 s?1). Our results demonstrate that it is possible to transfer the concept of strain‐promoted azide–alkyne cycloaddition (SPAAC) from purely organic azides to metal‐coordinated azido ligands. The favorable reaction kinetics for the ADIBO‐azido‐ligand cycloaddition and the well‐proven bioorthogonality of strain‐activated alkynes should pave the way for applications in living biological systems. 相似文献
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Prof. Kristof Van Hecke Dr. Thomas Cardinaels Dr. Peter Nockemann Jeroen Jacobs Louis Vanpraet Prof. Tatjana N. Parac‐Vogt Prof. Rik Van Deun Prof. Koen Binnemans Prof. Luc Van Meervelt 《Angewandte Chemie (International ed. in English)》2014,53(34):8959-8962
Evolution can increase the complexity of matter by self‐organization into helical architectures, the best example being the DNA double helix. One common aspect, apparently shared by most of these architectures, is the presence of covalent bonds within the helix backbone. Here, we report the unprecedented crystal structures of a metal complex that self‐organizes into a continuous double helical structure, assembled by non‐covalent building blocks. Built up solely by weak stacking interactions, this alternating tread stairs‐like double helical assembly mimics the DNA double helix structure. Starting from a racemic mixture in aqueous solution, the ruthenium(II) polypyridyl complex forms two polymorphic structures of a left‐handed double helical assembly of only the Λ‐enantiomer. The stacking of the helices is different in both polymorphs: a crossed woodpile structure versus a parallel columnar stacking. 相似文献
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Yingying Zhao Hong Chen Qiong Chen Yantao Qi Fan Yang Jie Tang Pingang He Fan Zhang 《中国化学》2014,32(11):1161-1168
An ultrasensitive and signal‐on electrochemiluminescence (ECL) aptasensor to detect target protein (thrombin or lysozyme) was developed using the host‐guest recognition between a metallocyclodextrin complex and single‐stranded DNA (ss‐DNA). The aptasensor uses both the photoactive properties of the metallocyclodextrins named multi‐tris(bipyridine)ruthenium(II)‐β‐cyclodextrin complexes and their specific recognition with ss‐DNA, which amplified the ECL signal without luminophore labeling. After investigating the ECL performance of different multi‐tris(bipyridine)ruthenium(II)‐β‐cyclodextrin (multi‐Ru‐β‐CD) complexes, tris‐tris(bipyridine)‐ruthenium(II)‐β‐cyclodextrin (tris(bpyRu)‐β‐CD) was selected as a suitable host molecule to construct an atasensor. First, double‐stranded DNA (ds‐DNA) formed by hybridization of the aptamer and its target DNA was attached to a glassy carbon electrode via coupling interaction, which showed low ECL intensity with 2‐(dibutylamino) ethanol (DBAE) as coreactant, because of the weak recognition between ds‐DNA and tris(bpyRu)‐β‐CD. Upon addition of the corresponding protein, the ECL intensity increased when target ss‐DNA was released because of the higher stability of the aptamer‐protein complex than the aptamer‐DNA one. A linear relationship was observed in the range of 0.01 pmol/L to 100 pmol/L between ECL intensity and the logarithm of thrombin concentrations with a limited detection of 8.5 fmol/L (S/N=3). Meanwhile, the measured concentration of lysozyme was from 0.05 pmol/L to 500 pmol/L and the detection limit was 33 fmol/L (S/N=3). The investigations of proteins in human serum samples were also performed to demonstrate the validity of detection in real clinical samples. The simplicity, high sensitivity and specificity of this aptasensor show great promise for practical applications in protein monitoring and disease diagnosis. 相似文献
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Giulia Lavarda Daiki Shimizu Toms Torres Atsuhiro Osuka 《Angewandte Chemie (International ed. in English)》2020,59(8):3127-3130
Peripherally metalated porphyrinoids are promising functional π‐systems displaying characteristic optical, electronic, and catalytic properties. In this work, 5‐(2‐pyridyl)‐ and 5,10,15‐tri(2‐pyridyl)‐BIII‐subporphyrins were prepared and used to produce cyclometalated subporphyrins by reactions with [Cp*IrCl2]2, which proceeded through an efficient C?H activation to give the corresponding mono‐ and tri‐IrIII complexes, respectively. While the mono‐IrIII complex was obtained as a diastereomeric mixture, a C3‐symmetric tri‐IrIII complex with the three Cp*‐units all at the concave side was predominantly obtained in a high yield of 90 %, which displays weak NIR phosphorescence even at room temperature in degassed CH2Cl2, differently from the mono‐IrIII complexes. 相似文献
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Photochemical Reduction of Low Concentrations of CO2 in a Porous Coordination Polymer with a Ruthenium(II)–CO Complex 下载免费PDF全文
Dr. Takashi Kajiwara Machiko Fujii Dr. Masahiko Tsujimoto Dr. Katsuaki Kobayashi Dr. Masakazu Higuchi Prof. Dr. Koji Tanaka Prof. Dr. Susumu Kitagawa 《Angewandte Chemie (International ed. in English)》2016,55(8):2697-2700
Direct use of low pressures of CO2 as a C1 source without concentration from gas mixtures is of great interest from an energy‐saving viewpoint. Porous heterogeneous catalysts containing both adsorption and catalytically active sites are promising candidates for such applications. Here, we report a porous coordination polymer (PCP)‐based catalyst, PCP‐RuII composite, bearing a RuII‐CO complex active for CO2 reduction. The PCP‐RuII composite showed improved CO2 adsorption behavior at ambient temperature. In the photochemical reduction of CO2 the PCP‐RuII composite produced CO, HCOOH, and H2. Catalytic activity was comparable with the corresponding homogeneous RuII catalyst and ranks among the highest of known PCP‐based catalysts. Furthermore, catalytic activity was maintained even under a 5 % CO2/Ar gas mixture, revealing a synergistic effect between the adsorption and catalytically active sites within the PCP‐RuII composite. 相似文献