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Ruthenium
Kinds of Ruthenium Terms modified by Ruthenium Selected AbstractsIodine(V)/Ruthenium(III)-Cocatalyzed Oxidations: A Highly Efficient Tandem Catalytic System for the Oxidation of Alcohols and Hydrocarbons with OxoneCHEMISTRY - A EUROPEAN JOURNAL, Issue 42 2009Mekhman Tandem catalysis: An extremely mild and efficient tandem catalytic system for the oxidation of alcohols and hydrocarbons based on a RuIII -catalyzed reoxidation of ArIO to ArIO2 by using Oxone as a stoichiometric oxidant is reported (see scheme). [source] Side-chain terpyridine polymers through atom transfer radical polymerization and their ruthenium complexesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2005Nikos P. Tzanetos Abstract Polymers containing side-chain terpyridine ligands of well-defined architectures and controllable molecular weights and molecular weight distributions are reported. These polymers were synthesized by the atom transfer radical polymerization (ATRP) of a newly synthesized terpyridine monomer with three functional initiators. The obtained polymers were characterized with 1H NMR and gel permeation chromatography techniques. The efficiency of the ATRP technique and the overall control of the molecular characteristics of the polymers were demonstrated by a kinetic study of the polymerization reaction. Subsequently, the ruthenium(III)/ruthenium(II) complexation chemistry was employed for the attachment of bis(dodecyloxy)-functionalized terpyridine moieties onto each side 2,2,:6,,2,-terpyridine unit of the main polymeric backbone. Thus, the grafting approach was successfully combined with the metal,ligand coordination chemistry for the preparation of highly soluble polymeric complexes. The resulting complexes were fully characterized by means of 1H NMR, gel permeation chromatography, and ultraviolet,visible spectroscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4838,4848, 2005 [source] Electrochemiluminescence Based on Solid State Tri(4,7-diphenyl-1,10-phenanthroline) Ruthenium(II) Ditetrakis(4-chlorophenyl) Borate Immobilized on Carbon FibersELECTROANALYSIS, Issue 12 2010Chunhua Liu Abstract A simple method for immobilization of tri(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) ditetrakis(4-chlorophenyl) borate ([Ru(dpp)3][(4-Clph)4B]2) on carbon fiber electrodes was developed. Excellent electrochemical activity and electrochemiluminescence (ECL) signal of the coated carbon fiber electrodes were observed using oxalate as the co-reactant. In addition, the effects of pH, scan rate, nitrogen and oxygen on ECL intensity were also studied. To demonstrate the reliability, the coated carbon fiber electrodes were used as ECL detectors and very low concentration of phenol was detectable (5.0×10,8,M). [source] Voltammetric Analysis of Trace Levels of Platinum Group Metals , Principles and ApplicationsELECTROANALYSIS, Issue 21 20072Article first published online: 4 OCT 200, Clinio Locatelli Abstract The compelling use of autocatalytic converters, containing platinum group metals (PGMs), has been the cause, in the environmental and biological matrices, of an increasing concentration of such metals. For this reason, in the last decade, the literature has reported several papers regarding analytical procedures for the determination of Pt(II), Pd(II) and Rh(III) in real samples, generally employing spectroscopic methods. The present review intends to highlight the contribution of the voltammetric techniques for the determination of these metals, including also those less investigated, i.e. Iridium, Osmium and Ruthenium. [source] Ruthenium ,6 -Hexamethylbenzene Complexes Containing Dichalcogenoimidodiphosphinate LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2009Wai-Man Cheung Abstract Treatment of [Ru(,6 -C6Me6)Cl2]2 with AgOTf (OTf, = triflato) followed by K[N(R2PQ)2] gave the 16-electron complexes [Ru(,6 -C6Me6){,2 -N(R2PQ)2}][OTf] [Q = S, R = Ph (1) or iPr (2); Q = Se, R = Ph (3) or iPr (4)] which were isolated as air-stable blue or dark green crystals. For complex 1, when the crude product was recrystallised from CH2Cl2/hexane in air, orange crystals of [Ru(,6 -C6Me6){,3 -N(Ph2PS)2}][OTf] (1a) were isolated as a minor product. The reaction of compound 1 with ammonia, hydrazine hydrate and 4,4,-bipyridyl(4,4,-bpy) gave the 18-electron adducts [Ru(,6 -C6Me6){,2 -N(Ph2PS)2}L][OTf] [L = NH3 (5), N2H4 (6)] and dinuclear[{Ru(,6 -C6Me6)[,2 -N(Ph2PS)2]}2(,-4,4,-bpy)][OTf]2 (7), respectively. Treatment of compound 2 with Li[BEt3H] and NaBH4 afforded the ethyl [Ru(,6 -C6Me6){N(iPr2PS)2}Et] (8) andhydride [Ru(,6 -C6Me6){,2 -N(iPr2PS)2}H] (9) compounds, respectively. Formal potentials for Ru[N(R2PQ)2] complexes have been determined. The structures for complexes 1, 1a, 5, 6, 8 and 9 have been established by X-ray crystallography. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Oligonucleotide Duplexes with Tethered Photoreactive Ruthenium(II) Complexes: Influence of the Ligands and Their Linker on the Photoinduced Electron Transfer and Crosslinking Processes of the Two StrandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 4 2009Stéphanie Deroo Abstract The photoreactivity of new RuII -oligonucleotide conjugates is investigated in the presence of their complementary strands. The goal is to determine the origins of different effects of parameters that control the photocrosslinking process of the two strands. Therefore, two RuII compounds, either [Ru(tap)3]2+or [Ru(tap)2phen]2+ (tap = 1,4,5,8-tetraazaphenanthrene, phen = 1,10-phenanthroline) with different oxidation powers, were tethered with different linkers to either the 5,- or 3,-phosphate end of the probe strand before hybridization with the complementary strand. These systems were studied by time-resolved emission spectroscopy, UV/Vis absorption experiments, PAGE and MS (ESI) analyses. The best yields of photocrosslinking (45,%) obtained with [Ru(tap)3]2+ tethered to the 3,-position are due to (i) a higher oxidation power of the complex and (ii) its attachment at the 3,-position. Indeed, this tethering favours the interaction of the Ru compound with the duplex and, therefore, inhibits its photodechelation. This work allows better design of sequence-specific DNA photodamaging agents prior to biological applications.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Dynamic Stereochemical Behaviour of Congested Ruthenium(II) Complexes Containing Asymmetric Thioether Ligands Based on Pyridine and PyrimidineEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 30 2008Giuseppe Tresoldi Abstract The asymmetric thioethers L [L = 2-pyridylmethyl 2,-pyrimidyl sulfide (pps) and 2-(4-methylpyrimidyl) 2,-pyridylmethyl sulfide (mps)] reacted with cis -[RuCl2(N,N -L,)2] [L, = di-2-pyridyl sulfide (dps); 2,2,-bis(4-methylpyridyl) sulfide (4mdps); 2,2,-bis(5-methylpyridyl) sulfide (5mdps)] to give the five-membered-ring chelate complexes [Ru(N,N -L,)2(Npyridine,S -L)]++ as the major products (92,95,%). Because the sulfur and ruthenium atoms are stereogenic centres, with (R) and (S) and , and , configurations, respectively, four isomers, including the enantiomers were obtained. At low temperature and in the methylene region of the 1H NMR spectra, two AB systems due to the enantiomer couples ,S ,R (a) and ,R ,S (b) were observed with abundances of 77,89 and 6,18,%, respectively. Furthermore, NMR spectroscopic investigations showed that the hybrid polydentate ligands L change their coordination mode. Thus, although a and b largely predominate, a mixture of species containing L and the Ru(N,N -L,)2 unit in the ratio 1:1 are present. The four-membered-ring chelate complexes [Ru(N,N -L,)2(Npyrimidine,S -L)]++ (c), as minor species (abundance 1,8,%), are always observed, whereas the dinuclear species [{Ru(N,N -L,)2}2(,-L)2]+4 (d, e) are observed when L, = dps or 5mdps. In these cases, four AB systems are assigned to dinuclear species d and e containing two bridging L that act as Npyridine,S- or Npyridine,Npyrimidine -donor ligands. The 1H NMR spectra are temperature dependent in that at low temperature the complexes undergo inversion of the chiral centre of the coordinated sulfur atom (a [rlhar2] b) and the dimer (d, e) and monomer (c) are in equilibrium; at higher temperatures the complexes undergo a structural dynamic rearrangement, which involves exchange between the coordinated and uncoordinated N atoms (b [rlhar2] c). One-dimensional band-shape analysis of the exchanging methylene and methyl proton signals showed that the energy barriers for inversion of the sulfur centre are in the 50,53 kJ,mol,1 range, whereas those for the higher-temperatures process are in the 62,68 kJ,mol,1 range. The possible mechanisms of the processes are discussed. NMR spectroscopic findings suggest that inversion at the sulfur centre occurs without any bond rupture, whereas the exchange, at higher temperatures (b [rlhar2] c), is a dissociative process involving the breaking of a Ru,Npyridine bond.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Mechanistic Insights into Acetophenone Transfer Hydrogenation Catalyzed by Half-Sandwich Ruthenium(II) Complexes Containing 2-(Diphenylphosphanyl)aniline , A Combined Experimental and Theoretical StudyEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 28 2008Alessia Bacchi Abstract Several new half-sandwich ruthenium(II) complexes containing 2-(diphenyphosphanyl)aniline (PNH2) of formula {Ru[(,2P,N)PNH2](p -cymene)Cl}Y [Y = Cl (1a), PF6 (1b), BF4 (1c), BPh4 (1d), TfO (1e)] were synthesized and fully characterized both in solution (1H NMR and 31P{1H} NMR spectroscopy) and in the solid state (FTIR, X-ray analysis on single crystal). Complexes 1a and 1b are active precatalysts in the hydrogen transfer reaction of acetophenone, leading to tof values up to 4440 h,1. In comparison, the {Ru[(,2P,N)PNMe2](p -cymene)Cl}Cl complex leads to a tof value of 100 h,1 under the same catalytic conditions. The mechanism through which the precatalysts operate was deeply explored by high-resolution MS (ESI) and DFT/PCM studies. The results reveal that the complexes containing PNH2 operate through a bifunctional mechanism analogous to that proposed for diamines and amino alcohol ligands. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Bis(acetylido) Complexes of Ruthenium(II) Bearing Monodentate Phosphane LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 27 2008Leslie D. Field Abstract Terminal acetylenes react with cis -RuMe2(PMe3)4 to form the bis(acetylido) complexes cis/trans -Ru(C,CR)2(PMe3)4 in good yield. The structures of trans - 2 (R = Ph), cis - 3 (R = p -C6H4 -OMe), trans - 4 (R = p -C6H4 -Me), cis - 6 (R = Me), trans - 7 (R = SiMe3) and cis - 8 (R = H) were determined by X-ray crystallography. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] N -(Aryl)picolinamide Complexes of Ruthenium: Usual Coordination and Strategic CyclometalationEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 9 2007Sumon Nag Abstract Reaction of five N -(4- R -phenyl)picolinamides (R = OCH3, CH3, H, Cl, and NO2) with [Ru(PPh3)2(CO)2Cl2] in refluxing 2-methoxyethanol in the presence of a base (NEt3) affords two geometrical isomers of a group of complexes (1-R and 2-R), each of which contains an amide ligand coordinated to the metal center as a monoanionic bidentate N,N donor along with two triphenylphosphanes, a carbonyl, and a hydride. Similar reaction of N -(naphthyl)picolinamide with [Ru(PPh3)2(CO)2Cl2] affords an organometallic complex, 3, in which the amide ligand is coordinated to the metal center, by C,H activation of the naphthyl ring at the 8-position, as a dianionic tridentate N,N,C donor along with two triphenylphosphanes and one carbonyl. Structures of the 1-OCH3, 2-CH3, and 3 complexes have been determined by X-ray crystallography. In all the complexes the two triphenylphosphanes are trans. In the 1-R complexes the hydride is trans to the pyridine nitrogen and in the 2-R complexes it is trans to the amide-nitrogen. All the complexes are diamagnetic, and show characteristic 1H NMR signals and intense MLCT transitions in the visible region. Cyclic voltammetry on all the complexes shows a RuII,RuIII oxidation within 0.71,0.93 V versus SCE. An oxidation and a reduction of the coordinated amide ligand are also observed within 1.29,1.69 V versus SCE and ,1.02 to ,1.21 V versus SCE respectively.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Chiral Half-Sandwich Ruthenium(II) Complexes as Catalysts in 1,3-Dipolar Cycloaddition Reactions of Nitrones with Methacrolein,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 16 2006Daniel Carmona Abstract Ruthenium complexes of formula [(,6 -arene)Ru(LL*)(H2O)][SbF6]2 (arene = C6H6, p -MeC6H4iPr, C6Me6; LL* = bidentate chelate chiral ligand with PN, PP or NN donor atoms) have been tested as catalyst precursors for the asymmetric 1,3-dipolar cycloaddition of nitrones to methacrolein. The reaction occurs quantitatively with perfect endo selectivity and moderate enantioselectivity (up to 74,% ee). The ruthenium aqua complexes can be prepared from the corresponding chlorides, [(,6 -arene)RuCl(LL*)][SbF6]. Dipolarophile intermediates [(,6 -arene)Ru(PNiPr)(methacrolein)][SbF6]2 {PNiPr = (4S)-2-(2-diphenylphosphanylphenyl)-4-isopropyl-1,3-oxazoline} as well as nitrone-containing complexes [(p -MeC6H4iPr)Ru(PNiPr)(nitrone)][SbF6]2 (nitrone = N -benzylidenephenylamine N -oxide, N -benzylidenemethylamine N -oxide, 3,4-dihydroisoquinoline N -oxide) have been also isolated and characterised. The crystal structures of the chlorides (RRu)-[(,6 -C6Me6)RuCl(PNiPr)][SbF6], (RRu)-[(,6 -C6H6)RuCl(PNInd)][SbF6] {PNInd = (3aR,8aS)-2-[2-(diphenylphosphanyl)phenyl]-3a,8a-dihydroindane[1,2- d]oxazole} and those of the aqua solvates (RRu)-[(,6 -arene)Ru(PNiPr)(H2O)][SbF6]2 (arene = C6H6, C6Me6) were determined by X-ray diffraction methods. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Synthesis, Crystal Structure, and Second-Order Nonlinear Optical Properties of Ruthenium(II) Complexes with Substituted Bipyridine and Phenylpyridine LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2006Laurence Labat Abstract Two new ruthenium(II) complexes of formula [Ru(bpy)2(L1)][PF6] and [Ru(bpy)2(L2)][PF6]2 are reported. HL1 is a (nitrophenyl)ethenyl-substituted phenylpyridine ligand, and L2 is the bipyridine analogue of HL1. The X-ray crystal structure of [Ru(bpy)2(L1)][PF6] has been solved, and the compound is found to crystallize in the monoclinic C2/c space group. The electronic spectrum of the cyclometalated derivative [Ru(bpy)2(L1)][PF6] exhibits a low-lying transition that is red-shifted from 454 to 546 nm relative to that of the parent bipyridine-based complex, which reveals an important charge-transfer character. To support this assumption, the nonlinear optical properties were investigated by the hyper-Rayleigh scattering technique and indicate a molecular static hyperpolarizability (,0) equal to 230,×,10,30 cm5,esu,1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Synthesis and Characterization of Two Novel, Mono-Lacunary Dawson Polyoxometalate-Based, Water-Soluble Organometallic Ruthenium(II) Complexes: Molecular Structure of [{(C6H6)Ru(H2O)}(,2 -P2W17O61)]8,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2006Yoshitaka Sakai Abstract The synthesis and structural characterization of a novel class of mono-lacunary Dawson polyoxometalate-(POM-)based, water-soluble organometallic complexes, which are expected to be effective homogeneous oxidation catalyst precursors in water, is described. The organometallic complexes K8[{(C6H6)Ru(H2O)}(,2 -P2W17O61)]·12H2O (1) and K8[{(p -cymene)Ru(H2O)}(,2 -P2W17O61)]·16H2O (2) were successfully prepared by direct reactions of the mono-lacunary Dawson POM K10[,2 -P2W17O61]·19H2O with the organometallic precursors [(C6H6)RuCl2]2 and [(p -cymene)RuCl2]2, respectively, in aqueous media and characterized by complete elemental analysis, thermogravimetric and differential thermal analyses (TG/DTA), and FT-IR and solution (1H, 13C, 31P, and 183W) NMR spectroscopy. The molecular structure of [{(C6H6)Ru(H2O)}(,2 -P2W17O61)]8, (1a), in which the binding of the cationic organometallic group {(C6H6)Ru(H2O)}2+ occurs through two oxygen atoms of the four available oxygen atoms in the mono-lacunary site of the POM, resulting in overall C1 symmetry, was successfully determined by single-crystal X-ray analysis. Interestingly, the hydrophilicity of the organometallic precursors is greatly enhanced by binding to a mono-lacunary Dawson POM with higher hydrophilicity. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Characterization by NMR Spectroscopy, X-ray Analysis and Cytotoxic Activity of the Ruthenium(II) Compounds [RuL3](PF6)2(L = 2-Phenylazopyridine or o -Tolylazopyridine) and [RuL'2L"](PF6)2(L', L" = 2-Phenylazopyridine, 2,2'-Bipyridine)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2005Anna C. G. Hotze Abstract Tris(ligand) complexes [RuL3](PF6)2 (L = 2-phenylazopyridine or o -tolylazopyridine) and mixed ligand [RuL'2L"](PF6)2 (L' and L" are 2-phenylazopyridine or 2,2'-bipyridine) have been synthesized, structurally characterized and investigated for cytotoxic activity. These complexes are important to study the hypothesis that the compound ,-[Ru(azpy)2Cl2] (azpy = 2-phenylazopyridine) exhibits a high cytotoxicity due to its two cis chloride ligands, which might be exchanged for biological targets as DNA. Molecular structures of mer -[Ru(azpy)3](PF6)2 (1) and mer -[Ru(tazpy)3](PF6)2 (5) (tazpy = o -tolylazopyridine) have been determined by X-ray diffraction. Series of complexes [RuL3](PF6)2 and [RuL'2L"](PF6)2 show interesting NMR spectroscopic data; e.g. the spectrum of mer -[Ru(azpy)3](PF6)2 (1) shows extremely broadened resonances at room temp. but sharpened resonances at low temperature. In the 1H NMR spectra of compounds [Ru(azpy)2(bpy)]2+ and [Ru(bpy)2(azpy)]2+ (bpy = 2,2-bipyridine), respectively, less broadened (room temp.) or completely sharp resonances (room temp.) occur in comparison to 1 (under same conditions). By selecting the right temperature and/or concentration, NMR spectra of these series of compounds have been resolved using 2D COSY and NOESY NMR spectroscopy. Remarkably, the cytotoxicity data against a series of human tumor cell lines (A498, EVSA-T, H226, IGROV, M19, MCF-7 and WIDR) show a moderate cytotoxicity for these series of tris(ligand) complexes. So, even though no chloride ligands are present in these tris(ligand) complexes, a considerable cytotoxic activity is observed. This would imply that the 2-phenylazopyridine ruthenium(II) complexes act by a completely different mechanism than the well-known cisplatin. This finding is important, because an anticancer compound acting via a different mechanism is a prerequisite in designing new anticancer drugs. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] A Ruthenium(II)-Complexed Rotaxane Whose Ring Incorporates a 6,6,-Diphenyl-2,2,-bipyridine: Synthesis and Light-Driven MotionsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2005Jean-Paul Collin Abstract By incorporating a 6,6'-diphenyl-2,2'-bipyridine (dpbipy) fragment in a ring, endo coordination of a ruthenium(II) center is performed selectively and almost quantitatively. The threaded system, containing a helical fragment, could be fully characterized. When the terminal functions of the rod-shaped helical complex threaded through the macrocycle are phenol groups, the complete rotaxane is prepared by the classical Williamson stoppering reaction in moderate yield. Light-induced motions of the unstoppered system (pseudorotaxane) and the real rotaxane have been studied. Under visible light irradiation, quantitative decoordination of the dpbipy-containing ring is observed, leading to the separate fragments (ring and helical thread) or to a new rotaxane (uncoordinated ring threaded by the dumbbell). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Ruthenium(II)-Catalyzed Cyclization of Oxabenzonorbornenes with Propargylic Alcohols: Formation of IsochromenesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 24 2006Karine Villeneuve Abstract The ruthenium-catalyzed cyclization of a propargylic alcohol with an oxabenzonorbornene in methanol leads to an unanticipated isochromene framework. The catalytic cycle to form this product is believed to go through an oxidative cyclization of the two unsaturated partners with the ruthenium catalyst, followed by ,-hydride elimination, tautomerization andhydroruthenation. The ruthenacyclobutane thus obtained further undergoes [2+2] cycloreversion to form a ruthenium,carbene intermediate that atypically rearranges via a [1,3]-alkoxide shift and finally reductively eliminates to produce the desired compound. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Synthesis, DNA-Binding and Photocleavage Studies of the Ruthenium(II) Complexes [Ru(phen)2(ppd)]2+ and [Ru(phen)(ppd)2]2+ (ppd=Pteridino[6,7- f],[1,10]phenanthroline-11,13(10H,12H)-dione, phen=1,10-Phenanthroline)HELVETICA CHIMICA ACTA, Issue 3 2008Feng Gao Abstract Two new complexes, [Ru(phen)2(ppd)]2+ (1) and [Ru(phen)(ppd)2]2+ (2) (ppd=pteridino[6,7- f],[1,10]phenanthroline-11,13(10H,12H)-dione, phen=1,10-phenanthroline) were synthesized and characterized by ES-MS, 1H-NMR spectroscopy, and elemental analysis. The intercalative DNA-binding properties of 1 and 2 were investigated by absorption-spectroscopy titration, luminescence-spectroscopy studies, thermal denaturation, and viscosity measurements. The theoretical aspects were further discussed by comparative studies of 1 and 2 by means of DFT calculations and molecular-orbital theory. Photoactivated cleavage of pBR322 DNA by the two complexes were also studied, and 2 was found to be a much better photocleavage reagent than 1. The mechanism studies revealed that singlet oxygen and the excited-states redox potentials of the complex may play an important role in the DNA photocleavage. [source] Synthesis, DNA Binding, and DNA Photocleavage of the Ruthenium(II) Complexes [Ru(bpy)(btip)]2+ and [Ru(dmb)(btip)]2+ (bpy,=,2,2,-Bipyridine; btip,=,2-Benzo[b]thien-2-yl-1H -imidazo[4,5- f],[1,10]phenanthroline; dmb,=,4,4,-Dimethyl-2,2,-bipyridine)HELVETICA CHIMICA ACTA, Issue 1 2007Li-Feng Tan Abstract The new polypyridyl ligand btip (=,2-benzo[b]thien-2-yl-1H -imidazo[4,5- f],[1,10]phenanthroline) and its RuII complexes [Ru(bpy)2(btip)]2+ (1; bpy,=,2,2,-bipyridine) and [Ru(dmb)2(btip)]2+ (2; dmb,=,4,4,-dimethyl-2,2,-bipyridine) were synthesized and characterized by elemental analysis, MS, and 1H-NMR. The DNA-binding properties of the two complexes to calf-thymus DNA (CT-DNA) were investigated by different spectrophotometric methods and viscosity measurements. The results suggest that both complexes bind to CT-DNA through intercalation. Also, when irradiated at 400,nm, the two complexes promote the photocleavage of plasmid pBR-322 DNA. Thereby, under comparable experimental conditions, complex 1 cleaves DNA more effectively than complex 2 does. Mechanistic studies reveal that singlet oxygen (1O2) and hydroxyl radicals (OH.) play a significant role in the photocleavage. [source] Silicon Surface-Bound Redox-Active Conjugated Wires Derived From Mono- and Dinuclear Iron(II) and Ruthenium(II) Oligo(phenyleneethynylene) Complexes,ADVANCED MATERIALS, Issue 10 2008Nicolas Gauthier Electron-rich mononuclear Fe(II) or dinuclear Fe(II)/Ru(II) acetylide complexes are photochemically grafted onto hydrogenated silicon surfaces following a simple and mild one-step procedure. The monolayers of redox-active organometallics that are formed exhibit efficient electrical communication between their bound metallic centers and the silicon surface through interfacial SiC bonds. [source] Photolithographic Patterning of Ring-Opening Metathesis Catalysts on Silicon,ADVANCED MATERIALS, Issue 1 2005F. Harris Ruthenium-based metathesis catalysts have been successfully covalently bound to a thermal oxide layer on a Si(100) wafer. Selective inactivation of the catalyst is achieved via exposure to UV light using standard photolithographic techniques. Subsequent exposure of the wafer to a suitable monomer results in the formation of a patterned polymeric film that is covalently attached to the oxide layer (see Figure). [source] One-Pot Synthesis of Quinoline Derivatives Directly from Terminal Alkynes via Sequential Ruthenium(II) and Acid CatalysisADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010Min Zhang Abstract A convenient one-pot synthesis of 2,3-disubstituted, 2,3,6-trisubstituted, and 2,3,6,7-tetrasubstituted quinoline analogues from terminal alkynes via sequential ruthenium(II) and para -toluenesulfonic acid (p -TSA) co-catalyzed reactions is described. The catalytic process is shown to take place first via intermediate formation of an allyl ketone and then addition of an aniline derivative to the allyl ketone. The p -TSA is a catalyst for both allyl ketone and quinoline synthetic steps. The method allowed us to synthesize a wide range of quinoline derivatives and introduce different substituents by employing various simple starting materials. The reaction allows the synthesis of halogen-containing products. [source] Mixed Isobutylphobane/N-Heterocyclic Carbene Ruthenium- Indenylidene Complexes: Synthesis and Catalytic Evaluation in Olefin Metathesis ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010Xavier Sauvage Abstract Two new second generation ruthenium(II) dichloride-indenylidene complexes [RuCl2(9-isobutylphosphabicyclo[3.3.1]nonane)(NHC)(3-phenyl-1-indenylidene)], where NHC=1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (SIMes) or its unsaturated imidazol-2-ylidene analogue (IMes), were isolated in high yields upon heating a tetrahydrofuran (THF) solution of the diphosphane complex [RuCl2(isobutylphobane)2(3-phenyl-1-indenylidene)] with a two-fold excess of the corresponding imidazol(in)ium-2-carboxylate zwitterions. Both products were characterized by 1H, 13C, and 31P,NMR spectroscopy, and the molecular structure of [RuCl2(isobutylphobane)(SIMes)(3-phenyl-1-indenylidene)] was determined by X-ray diffraction analysis. A close inspection of the packing structure revealed the presence of different types of intra- and intermolecular interactions that enhanced the global stability of the crystals, while low temperature NMR experiments showed the existence of two distinct rotational isomers due to the unsymmetrical nature of the phobane ligand. The catalytic activity of both compounds was assessed in olefin metathesis using benchmark ring-opening metathesis polymerization, ring-closing metathesis (RCM), and cross-metathesis reactions, and compared with those of related first and second generation ruthenium-benzylidene and indenylidene catalyst precursors. Kinetic studies confirmed the high thermal stability of the mixed isobutylphobane/N-heterocyclic carbene complexes, which suffered from a slow initiation efficiency compared to other catalytic systems based on the tricyclohexylphosphane ligand. However, the remarkable robustness of [RuCl2(isobutylphobane)(SIMes)(3-phenyl-1-indenylidene)] was beneficial for performing the RCM of diethyl 2,2-bis(2-methylallyl)malonate. Monitoring the formation of the ruthenium-methylidene active species [RuCl2(isobutylphobane)(SIMes)(CH2)] derived from this precursor further demonstrated its ability to sustain long reaction times and high temperatures required to carry out the RCM of tetrasubstituted olefins. [source] Ruthenium(II)-Catalyzed Regioselective Synthesis of Allyl Ketones from Alkynes and their Silver(I)-Catalyzed Hydroarylation into ,-Functionalized KetonesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009Min Zhang Abstract The regioselective synthesis of ,,,-unsaturated ketones from terminal alkynes is achieved by cooperative action of tris(acetonitrile)pentamethylcyclopentadieneruthenium hexafluorophosphate [Cp*Ru(NCMe)3+ PF6,] and para -toluenesulfonic acid catalysts. These allyl ketones undergo direct regioselective hydroarylation/Friedel,Crafts reaction to introduce an electron-rich aryl group at the ,-position in the presence of ligand-free silver triflate (AgOTf) catalyst. Both catalytic reactions take place with atom economy and provide an alternative to the synthesis of a variety of allyl ketones and , -arylated ketones. [source] Recyclable Polymer- and Silica-Supported Ruthenium(II)-Salen Bis-pyridine Catalysts for the Asymmetric Cyclopropanation of OlefinsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Christopher Abstract Homogeneous ruthenium(II)-salen bis-pyridine complexes are known to be highly active and selective catalysts for the asymmetric cyclopropanation of terminal olefins. Here, new methods of heterogenization of these Ru-salen catalysts on polymer and porous silica supports are demonstrated for the facile recovery and recycle of these expensive catalysts. Activities, selectivities, and recyclabilities are investigated and compared to the analogous homogeneous and other supported catalysts for asymmetric cyclopropanation reactions. The catalysts are characterized with a variety of methods including solid state cross-polarization magic-angle spinning (CP MAS) 13C and 29Si,NMR, FT-IR, elemental analysis, and thermogravimetric analysis. Initial investigations produced catalysts possessing high selectivities but decreasing activities upon reuse. Addition of excess pyridine during the washing steps between cycles was observed to maintain high catalytic activities over multiple cycles with no impact on selectivity. Polymer-supported catalysts showed superior activity and selectivity compared to the porous silica-supported catalyst. Additionally, a longer, flexible linker between the Ru-salen catalyst and support was observed to increase enantioselectivity and diastereoselectivity, but had no effect on activity of the resin catalysts. Furthermore, the polymer-supported Ru-salen-Py2 catalysts were found to generate superior selectivities and yields compared to other leading heterogeneous asymmetric cyclopropanation catalysts. [source] Novel [Ruthenium(substituted-tetramethylcyclopentadiene) (2-quinolinecarboxylato)(allyl)] Hexafluorophosphate Complexes as Efficient Catalysts for Highly Regioselective Nucleophilic Substitution of Aliphatic Allylic SubstratesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2008Hui-Jun Zhang Abstract Stable [ruthenium(R-substituted-tetramethylcyclopentadiene)(2-quinolinecarboxylato)(1-R,-substituted-allyl) hexafluorophosphate (R=Me, R,=H, Me, n- Pr, Ph; R=t- Bu, R,=Me) and [ruthenium(pentamethylcyclopentadiene)(2-quinolinecarboxylato)(1- n -propylallyl)] tetrafluoroborate (4,a), as allylruthenium(IV) complexes, have been synthesized in one step, starting from [ruthenium(R-substituted-tetramethylcyclopentadiene)tris(acetonitrile) hexafluorophosphate or tetrafluoroborate complexes, quinaldic acid, and allylic alcohols. Single stereoisomers are obtained and the X-ray single crystal structure determinations of 3b (R=t- Bu, R,=Me) and 4,a allow one to specify the preferred arrangement. Complexes 3a (R=R,=Me) and 3b are involved as precatalysts favoring the formation of branched products in regioselective nucleophilic allylic substitution reactions, starting from ethyl 2- (E) -hexen-1-yl carbonate and chlorohexene as unsymmetrical aliphatic allylic substrates. Phenols, dimethyl malonate, and primary (aniline) and secondary (pyrrolidine, piperidine) amines have been used as nucleophiles under mild basic conditions. For the first time, the regioselectivity in favor of the branched product obtained from purely aliphatic allylic substrates is close to the high regioselectivity previously reached starting from cinnamyl-type substrates in the presence of ruthenium catalysts. [source] Amphiphilic Resin-Supported Ruthenium(II) Complexes as Recyclable Catalysts for the Hydrogenation of Supercritical Carbon DioxideADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2003Yoshihito Kayaki Abstract Dichloro- and dihydridoruthenium(II) catalysts attached to an amphiphilic resin (PS,PEG) were prepared and tested for hydrogenation of supercritical carbon dioxide (scCO2) in the presence of dimethylamine leading to N,N -dimethylformamide (DMF). The supported catalysts were successfully recyclable with only moderate loss of activity. [source] Ruthenium (II) complexes immobilized on swellable polyacrylate matrices: Synthesis and catalytic applicationsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Z. S. Liu Abstract RuH2(PPh3)4 has been immobilized on swellable polyacrylate matrices to provide heterogenized carboxylate-derivatives. These swellable polymer supported ruthenium (II) complex catalysts have been used in the transfer hydrogenation of aldehydes. Hydrogen donors are formate salt, cyclohexanol, and benzyl alcohol. The catalysts exhibit good activity for hydrogen transfer reduction of aldehydes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Ruthenium-based metathesis initiators: Development and use in ring-opening metathesis polymerizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2002Ulrich Frenzel Abstract For many years, olefin metathesis has been a central topic of industrial and academic research because of its great synthetic utility. The employed initiators cover a wide range of compounds, from simple transition-metal salts to highly sophisticated and well-defined alkylidene complexes. Currently, ruthenium-based catalysts are at the center of attention because of their remarkable tolerance toward oxygen, moisture, and numerous functionalities. This article focuses on recent developments in the field of ring-opening metathesis polymerization using ruthenium-based catalysts. ruthenium-based initiators and their applications to the preparation of advanced polymeric materials are briefly reviewed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2895,2916, 2002 [source] Ink-Jet Printing of Luminescent Ruthenium- and Iridium-Containing Polymers for Applications in Light-Emitting DevicesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 4 2005Emine Tekin Abstract Summary: Defined films of luminescent ruthenium(II) polypyridyl-poly(methyl methacrylate) (PMMA) and iridium(III) polypyridyl-polystyrene (PS) copolymers could be prepared by ink-jet printing. The copolymers were deposited on photoresist-patterned glass substrates. Films as thin as 120 nm could be printed with a roughness of 1 to 2%. In addition, the film thickness could be varied in a controlled way through the number of droplets deposited per unit area. The topography of the ink-jet printed films was analyzed utilizing an optical profilometer. The absorbance and emission spectra were measured using fast parallel UV-vis and fluorescence plate reader. Photo of the solutions of luminescent ruthenium (left) and iridium (right) containing polymers in a glass microtiter plate (top). The subsequently prepared films using ink-jet dispensing techniques are shown below. [source] Ruthenium (II) tris-bathophenanthroline disulfonate is well suitable for Tris-Glycine PAGE but not for Bis-Tris gelsPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 4 2007Jan Moebius Abstract Pre-cast bis(2-hydroxyethyl)iminotris(hydroxymethyl)methane (Bis-Tris) gels have proven to be very suitable for pre-fractionation for LC-MS/MS analysis due to high reliability and long stability. To visualize proteins within gels fluorescence dyes proved to be a good tradeoff between sensitivity and MS-compatibility. The custom-made ruthenium dye represents a low-cost alternative regarding fluorescence-based protein visualization with high sensitivity. We demonstrate, that this dye is incompatible with Bis-Tris gels, while using Tris-Glycine gels a competitive sensitivity to commercially available stains can be achieved. [source] | |||||||||||||||||||||||||||||||||||||