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Sample records for ruthenium 99

  1. Solid-state Ru-99 NMR spectroscopy: a useful tool for characterizing prototypal diamagnetic ruthenium compounds.

    PubMed

    Ooms, Kristopher J; Wasylishen, Roderick E

    2004-09-01

    The feasibility of (99)Ru NMR spectroscopy as a tool to characterize solid compounds is demonstrated. Results of the first solid-state (99)Ru NMR investigation of diamagnetic compounds are presented for Ru(NH(3))(6)Cl(2), K(4)Ru(CN)(6). xH(2)O (x = 0, 3), LaKRu(CN)(6), and Ru(3)(CO)(12). The sensitivity of the ruthenium magnetic shielding tensor to subtle changes in the local structure about the ruthenium nucleus is highlighted by comparing the (99)Ru isotropic chemical shift of Ru(NH(3))(6)Cl(2) in aqueous solutions and in the solid state. The narrow isotropic (99)Ru NMR peak observed for solid Ru(NH(3))(6)Cl(2) indicates that this compound is an ideal secondary reference sample for solid-state (99)Ru NMR studies. The isotropic (99)Ru chemical shift, (99)Ru nuclear quadrupolar coupling constant, C(Q), and quadrupolar asymmetry parameter of K(4)Ru(CN)(6). xH(2)O (x = 0, 3) are shown to be sensitive to x. For Ru(3)(CO)(12), the magnetic shielding tensors of each of the three nonequivalent Ru nuclei have spans of 1300-1400 ppm, and the (99)Ru C(Q) values are also similar, 1.36-1.85 MHz, and are surprisingly small given that (99)Ru has a moderate nuclear quadrupole moment. Information about the relative orientation of the Ru magnetic shielding and electric field gradient tensors has been determined for Ru(3)(CO)(12) from experimental (99)Ru NMR spectra as well as quantum chemical calculations. PMID:15339183

  2. Solid-State Ru-99 NMR Spectroscopy: A Useful Tool for Characterizing Prototypal Diamagnetic Ruthenium Compounds Compounds

    SciTech Connect

    Ooms, Kristopher J.; Wasylishen, Roderick E.

    2004-09-08

    The feasibility of 99Ru NMR spectroscopy as a tool to characterize solid compounds is demonstrated. Results of the first solid-state 99Ru NMR investigation of diamagnetic compounds are presented for Ru(NH3)6Cl2, K4Ru(CN)6 xH2O (x) 0, 3, LaKRu(CN)6, and Ru3(CO)12. The sensitivity of the ruthenium magnetic shielding tensor to subtle changes in the local structure about the ruthenium nucleus is highlighted by comparing the 99Ru isotropic chemical shift of Ru(NH3)6Cl2 in aqueous solutions and in the solid state. The narrow isotropic 99Ru NMR peak observed for solid Ru(NH3)6Cl2 indicates that this compound is an ideal secondary reference sample for solid-state 99Ru NMR studies.

  3. RECOVERY OF RUTHENIUM VALUES

    DOEpatents

    Grummitt, W.E.; Hardwick, W.H.

    1961-01-01

    A process is given for the recovery of ruthenium from its aqueous solutions by oxidizing the ruthenium to the octavalent state and subsequently extracting the ruthenium into a halogen-substituted liquid paraffin.

  4. Radiochemistry of ruthenium

    SciTech Connect

    Schulz, W W; Metcalf, S G; Barney, G S

    1984-06-01

    Information on ruthenium is presented. Topics include the following; isotopes and nuclear properties of ruthenium; review of the chemistry of ruthenium including metal and alloys, compounds of ruthenium, and solution chemistry; separation methods including volatilization of RuO{sub 4}, precipitation and coprecipitation, solvent extraction, chromatographic techniques, and analysis for radioruthenium. 445 refs., 7 figs., 23 tabs.

  5. Metals fact sheet: Ruthenium

    SciTech Connect

    1996-06-01

    Ruthenium, named after Ruthenia, a province in Western Russia, was discovered in 1827 by Osann in placer ores from Russia`s Ural mountains. A minor platinum group metal (PGM), Ruthenium was the last of the PGMs to be isolated. In 1844, Klaus prepared the first 6 grams of pure ruthenium metal.

  6. SOLVENT EXTRACTION OF RUTHENIUM

    DOEpatents

    Hyman, H.H.; Leader, G.R.

    1959-07-14

    The separation of rathenium from aqueous solutions by solvent extraction is described. According to the invention, a nitrite selected from the group consisting of alkali nitrite and alkaline earth nitrite in an equimolecular quantity with regard to the quantity of rathenium present is added to an aqueous solution containing ruthenium tetrantrate to form a ruthenium complex. Adding an organic solvent such as ethyl ether to the resulting mixture selectively extracts the rathenium complex.

  7. Ruthenium-coated ruthenium oxide nanorods

    SciTech Connect

    Ducati, Caterina; Dawson, Darryl H.; Saffell, John R.; Midgley, Paul A.

    2004-11-29

    The role of ruthenium and its oxides in catalysis, electrochemistry, and electronics is becoming increasingly important because of the high thermal and chemical stability, low resistivity, and unique redox properties of this metallic system. We report an observation of RuO{sub 2} nanorods decorated with nanometer size Ru metal clusters. We identify precise crystallographic relationships between metal and oxide, and provide a simple model for the synthesis of these structures, based on the theory of columnar growth. The high aspect ratio, high surface area, and quantum size crystalline decorations of these nanostructures make them particularly attractive candidates for further fundamental research and for advanced catalytic and electronic applications.

  8. RUTHENIUM DECONTAMINATION METHOD

    DOEpatents

    Gresky, A.T.

    1960-07-19

    A liquid-liquid extraction method of separating uranium from fission products is given. A small amount of a low molecular weight ketone is added to an acidic aqueous solution containing neutron-irradiated uranium and its associated fission products. The resulting solution is digested and then contacted with an organic liquid that extracts uranium values. The purpose of the step of digesting the aqueous solution in the presence of the ketone is to suppress the extractability of ruthenium.

  9. Moderated ruthenium fischer-tropsch synthesis catalyst

    DOEpatents

    Abrevaya, Hayim

    1991-01-01

    The subject Fischer-Tropsch catalyst comprises moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation.

  10. SEPARATION OF RUTHENIUM FROM AQUEOUS SOLUTIONS

    DOEpatents

    Callis, C.F.; Moore, R.L.

    1959-09-01

    >The separation of ruthenium from aqueous solutions containing uranium plutonium, ruthenium, and fission products is described. The separation is accomplished by providing a nitric acid solution of plutonium, uranium, ruthenium, and fission products, oxidizing plutonium to the hexavalent state with sodium dichromate, contacting the solution with a water-immiscible organic solvent, such as hexone, to extract plutonyl, uranyl, ruthenium, and fission products, reducing with sodium ferrite the plutonyl in the solvent phase to trivalent plutonium, reextracting from the solvent phase the trivalent plutonium, ruthenium, and some fission products with an aqueous solution containing a salting out agent, introducing ozone into the aqueous acid solution to oxidize plutonium to the hexavalent state and ruthenium to ruthenium tetraoxide, and volatizing off the ruthenium tetraoxide.

  11. Characterization And Dissolution Properties Of Ruthenium Oxides

    EPA Science Inventory

    Ruthenium oxides (RuO2•1.10H2O and RuO2) have been synthesized by forced hydrolysis and oxidation of ruthenium chloride. The resulting materials were extensively characterized to determine the crystallinity, surface area, and ruthenium oxidation ...

  12. SEPARATION OF RUTHENIUM FROM AQUEOUS SOLUTIONS

    DOEpatents

    Beederman, M.; Vogler, S.; Hyman, H.H.

    1959-07-14

    The separation of rathenium from a rathenium containing aqueous solution is described. The separation is accomplished by adding sodium nitrite, silver nitrate and ozone to the ruthenium containing aqueous solution to form ruthenium tetroxide and ihen volatilizing off the ruthenium tetroxide.

  13. Solventless synthesis of ruthenium nanoparticles

    NASA Astrophysics Data System (ADS)

    García-Peña, Nidia G.; Redón, Rocío; Herrera-Gomez, Alberto; Fernández-Osorio, Ana Leticia; Bravo-Sanchez, Mariela; Gomez-Sosa, Gustavo

    2015-06-01

    This paper presents a novel solventless method for the synthesis of zero-valent ruthenium nanoparticles Ru(0). The proposed method, although not entirely new in the nanomaterials world, was used for the first time to synthesize zero-valent ruthenium nanoparticles. This new approach has proved to be an environmentally friendly, clean, cheap, fast, and reproducible technique which employs low amounts of solvent. It was optimized through varying amounts of reducing salt on a determined quantity of precursor and measuring the effect of this variation on the average particle size obtained. The resulting products were fully characterized by powder XRD, TEM, HR-TEM, and XPS studies, all of which corroborated the purity of the nanoparticles achieved. In order to verify the advantages of our method over other techniques, we compared our nanoparticles with two common colloidal-synthesized ruthenium nanoparticles.

  14. Ruthenium-106 brachytherapy.

    PubMed

    Pe'er, Jacob

    2012-01-01

    Brachytherapy is the most common method for treating uveal melanoma, and currently the ruthenium-106 (Ru-106) and iodine-125 (I-125) applicators are the most frequently used. Ru-106 applicators were introduced by Prof. Peter Lommatzsch in the 1960s, and since then have been used widely by many ocular oncologists, mainly in Europe. The Ru-106 isotope is a beta ray (electron) emitter, and as such it has a limited depth of penetration. This is the reason why many experts use Ru-106 applicators for tumors with a maximal thickness of up to 7.0 mm, although others use it successfully for thicker tumors. The Ru-106 applicators are manufactured commercially and have a half-life of about 1 year. Ru-106 brachytherapy for uveal melanoma provides excellent local control rates and eye preservation with a relatively low recurrence rate. The main advantage of Ru-106 over other isotopes is the better preservation of vision in the treated eye, and less damage to the healthy parts of the eye due to its limited range of radiation. This can also be achieved by positioning the Ru-106 plaque eccentrically, away from the macula and optic nerve head. Ru-106 brachytherapy can be used in combination with other methods of treatment of uveal melanoma, such as local resection or transpupillary thermotherapy, and is sporadically combined with other isotopes, such as gamma-emitting cobalt-60 and I-125. PMID:22042011

  15. Precise ruthenium fission product isotopic analysis using dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS)

    SciTech Connect

    Brown, Christopher F.; Dresel, P. Evan; Geiszler, Keith N.; Farmer, Orville T.

    2006-05-09

    99Tc is a subsurface contaminant of interest at numerous federal, industrial, and international facilities. However, as a mono-isotopic fission product, 99Tc lacks the ability to be used as a signature to differentiate between the different waste disposal pathways that could have contributed to subsurface contamination at these facilities. Ruthenium fission-product isotopes are attractive analogues for the characterization of 99Tc sources because of their direct similarity to technetium with regard to subsurface mobility, and their large fission yields and low natural background concentrations. We developed an inductively coupled plasma mass spectrometry (ICP-MS) method capable of measuring ruthenium isotopes in groundwater samples and extracts of vadose zone sediments. Samples were analyzed directly on a Perkin Elmer ELAN DRC II ICP-MS after a single pass through a 1-ml bed volume of Dowex AG 50W-X8 100-200 mesh cation exchange resin. Precise ruthenium isotopic ratio measurements were achieved using a low-flow Meinhard-type nebulizer and long sample acquisition times (150,000 ms). Relative standard deviations of triplicate replicates were maintained at less than 0.5% when the total ruthenium solution concentration was 0.1 ng/ml or higher. Further work was performed to minimize the impact caused by mass interferences using the dynamic reaction cell (DRC) with O2 as the reaction gas. The aqueous concentrations of 96Mo and 96Zr were reduced by more than 99.7% in the reaction cell prior to injection of the sample into the mass analyzer quadrupole. The DRC was used in combination with stable-mass correction to quantitatively analyze samples containing up to 2-orders of magnitude more zirconium and molybdenum than ruthenium. The analytical approach documented herein provides an efficient and cost-effective way to precisely measure ruthenium isotopes and quantitate total ruthenium (natural vs. fission-product) in aqueous matrixes.

  16. IR-doped ruthenium oxide catalyst for oxygen evolution

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I. (Inventor); Narayanan, Sekharipuram R. (Inventor)

    2012-01-01

    A method for preparing a metal-doped ruthenium oxide material by heating a mixture of a doping metal and a source of ruthenium under an inert atmosphere. In some embodiments, the doping metal is in the form of iridium black or lead powder, and the source of ruthenium is a powdered ruthenium oxide. An iridium-doped or lead-doped ruthenium oxide material can perform as an oxygen evolution catalyst and can be fabricated into electrodes for electrolysis cells.

  17. Platinum-ruthenium-palladium fuel cell electrocatalyst

    DOEpatents

    Gorer, Alexander

    2006-02-07

    A catalyst suitable for use in a fuel cell, especially as an anode catalyst, that contains platinum at a concentration that is between about 20 and about 60 atomic percent, ruthenium at a concentration that is between about 20 and about 60 atomic percent, palladium at a concentration that is between about 5 and about 45 atomic percent, and having an atomic ratio of platinum to ruthenium that is between about 0.7 and about 1.2. Alternatively, the catalyst may contain platinum at a concentration that is between about 25 and about 50 atomic percent, ruthenium at a concentration that is between about 25 and about 55 atomic percent, palladium at a concentration that is between about 5 and about 45 atomic percent, and having a difference between the concentrations of ruthenium and platinum that is no greater than about 20 atomic percent.

  18. Platinum-ruthenium-nickel fuel cell electrocatalyst

    DOEpatents

    Gorer, Alexander

    2005-07-26

    A catalyst suitable for use in a fuel cell, especially as an anode catalyst, that contains platinum, ruthenium, and nickel, wherein the nickel is at a concentration that is less than about 10 atomic percent.

  19. Ruthenium Sesquisilicide: A Promising Thermoelectric Material

    NASA Technical Reports Server (NTRS)

    Vining, Cronin B.

    1993-01-01

    Report describes experimental investigation of thermoelectric properties of ruthenium sesquisilicide (RU2Si3). Suggests suitably doped Ru2Si3 could have thermoelectric figures of merit two or more times as large as SiGe.

  20. Lead-ruthenium pyrochlores as oxygen electrocatalysts

    NASA Technical Reports Server (NTRS)

    Anderson, E. B.; Taylor, E. J.; Moniz, G. A.

    1990-01-01

    An investigation of lead-ruthenium pyrochlores of the structure Pb2(Ru/2-x/Pb/x/) O7-y for use as oxygen electrocatalysts in alkaline media is discussed. Lead-ruthenium pyrochlore mixed metal oxides were prepared and characterized by X-ray diffraction, BET surface area, dry powder conductivity, and chemical stability. Gas diffusion electrodes were developed specifically for the lead-ruthenium pyrochlore materials. Also investigated were the effects of varying electrode fabrication parameters on the oxygen reduction performance of the lead-ruthenium pyrochlore electrocatalyst. Long-term stability performance was also evaluated. The oxygen reduction performance of the pyrochlore electrocatalyst is considerably higher than that of the state-of-the-art gold-platinum alloy electrocatalyst currently used by NASA. Furthermore, the pyrochlore electrocatalysts are attractive candidates for high-performance pressurized alkaline fuel cells.

  1. Highly sensitive catalytic spectrophotometric determination of ruthenium

    NASA Astrophysics Data System (ADS)

    Naik, Radhey M.; Srivastava, Abhishek; Prasad, Surendra

    2008-01-01

    A new and highly sensitive catalytic kinetic method (CKM) for the determination of ruthenium(III) has been established based on its catalytic effect on the oxidation of L-phenylalanine ( L-Pheala) by KMnO 4 in highly alkaline medium. The reaction has been followed spectrophotometrically by measuring the decrease in the absorbance at 526 nm. The proposed CKM is based on the fixed time procedure under optimum reaction conditions. It relies on the linear relationship where the change in the absorbance (Δ At) versus added Ru(III) amounts in the range of 0.101-2.526 ng ml -1 is plotted. Under the optimum conditions, the sensitivity of the proposed method, i.e. the limit of detection corresponding to 5 min is 0.08 ng ml -1, and decreases with increased time of analysis. The method is featured with good accuracy and reproducibility for ruthenium(III) determination. The ruthenium(III) has also been determined in presence of several interfering and non-interfering cations, anions and polyaminocarboxylates. No foreign ions interfered in the determination ruthenium(III) up to 20-fold higher concentration of foreign ions. In addition to standard solutions analysis, this method was successfully applied for the quantitative determination of ruthenium(III) in drinking water samples. The method is highly sensitive, selective and very stable. A review of recently published catalytic spectrophotometric methods for the determination of ruthenium(III) has also been presented for comparison.

  2. Thermodynamic properties of gaseous ruthenium species.

    PubMed

    Miradji, Faoulat; Souvi, Sidi; Cantrel, Laurent; Louis, Florent; Vallet, Valérie

    2015-05-21

    The review of thermodynamic data of ruthenium oxides reveals large uncertainties in some of the standard enthalpies of formation, motivating the use of high-level relativistic correlated quantum chemical methods to reduce the level of discrepancies. The reaction energies leading to the formation of ruthenium oxides RuO, RuO2, RuO3, and RuO4 have been calculated for a series of reactions. The combination of different quantum chemical methods has been investigated [DFT, CASSCF, MRCI, CASPT2, CCSD(T)] in order to predict the geometrical parameters, the energetics including electronic correlation and spin-orbit coupling. The most suitable method for ruthenium compounds is the use of TPSSh-5%HF for geometry optimization, followed by CCSD(T) with complete basis set (CBS) extrapolations for the calculation of the total electronic energies. SO-CASSCF seems to be accurate enough to estimate spin-orbit coupling contributions to the ground-state electronic energies. This methodology yields very accurate standard enthalpies of formations of all species, which are either in excellent agreement with the most reliable experimental data or provide an improved estimate for the others. These new data will be implemented in the thermodynamical databases that are used by the ASTEC code (accident source term evaluation code) to build models of ruthenium chemistry behavior in severe nuclear accident conditions. The paper also discusses the nature of the chemical bonds both from molecular orbital and topological view points. PMID:25905631

  3. Ruthenium indenylidene complexes containing dichalcogenoimidodiphosphinate ligands

    NASA Astrophysics Data System (ADS)

    Jia, Ai-Quan; Xin, Zhi-Feng; Chen, Qun; Leung, Wa-Hung; Zhang, Qian-Feng

    2012-07-01

    Reactions of ruthenium indenylidene starting material [Ru(PPh3)2(Ind)Cl2] (Ind = 3-phenylinden-1-ylidene) with potassium dichalcogenoimidodiphosphinates K[R2P(E)NP(E')R2] afforded a series of complexes [Ru(PPh3)(Ind){кE,кE'-R2P(E)NP(E')R2}Cl] [R = Ph, E = E' = S (1a); R = Ph, E = E' = Se (1b); R = iPr, E = E' = S (1c); R = iPr, E = E' = Se (1d); R = Ph, E = S, E' = Se (1e); R = iPr, E = S, E' = Se (1f)] which were characterized by microanalyses, IR and NMR spectroscopies. The molecular structure of 1a has been confirmed by single-crystal X-ray diffraction. The catalytic reactivity of the ruthenium indenylidene complexes in the ring closing metathesis of diethyl 1,2-diallylmalonate has also been investigated.

  4. Highly Selective Ruthenium Metathesis Catalysts for Ethenolysis

    PubMed Central

    Thomas, Renee M.; Keitz, Benjamin K.; Champagne, Timothy M.; Grubbs, Robert H.

    2011-01-01

    N-aryl, N-alkyl N-heterocyclic carbene (NHC) ruthenium metathesis catalysts are highly selective toward the ethenolysis of methyl oleate, giving selectivity as high as 95% for the kinetic, ethenolysis products over the thermodynamic, self-metathesis products. The examples described herein represent some of the most selective NHC-based ruthenium catalysts for ethenolysis reactions to date. Furthermore, many of these catalysts show unusual preference and stability toward propagating as a methylidene species, and provide good yields and turnover numbers (TONs) at relatively low catalyst loading (<500 ppm). A catalyst comparison showed that ruthenium complexes bearing sterically hindered NHC substituents afforded greater selectivity and stability, and exhibited longer catalyst lifetime during reactions. Comparative analysis of the catalyst preference for kinetic versus thermodynamic product formation was achieved via evaluation of their steady-state conversion in the cross-metathesis reaction of terminal olefins. These results coincided with the observed ethenolysis selectivities, in which the more selective catalysts reach a steady-state characterized by lower conversion to cross-metathesis products compared to less selective catalysts, which show higher conversion to cross-metathesis products. PMID:21510645

  5. The biokinetics of ruthenium in the human body

    SciTech Connect

    Leggett, Richard Wayne

    2011-01-01

    The biokinetics of ruthenium (Ru) in the human body is of interest due mainly to the potential for occupational or environmental exposure to 106Ru (T1/2 = 373.6 d) and 103Ru (T1/2 = 39.3 d), which typically represent a significant portion of the fission products in a reactor inventory. During reactor operations or nuclear fuel reprocessing these ruthenium isotopes may be present as ruthenium tetroxide (RuO4) vapor, a highly mobile form of ruthenium that has been involved in a number of cases of accidental exposure to 106Ru or 103Ru. This paper summarizes the biokinetic database for ruthenium and proposes a new respiratory model for inhaled RuO4 vapor, a new biokinetic for systemic (absorbed) ruthenium, and material-specific gastrointestinal absorption fractions for ruthenium. The proposed respiratory model for RuO4 differs from the current ICRP model mainly in that it depicts slower clearance of deposited activity from the respiratory tract and lower absorption to blood than depicted in the current ICRP model. The proposed systemic biokinetic model depicts more realistic paths of movement of absorbed ruthenium in the body than the current ICRP model and, in contrast to the present model, a less uniform distribution of systemic activity. Implications of the proposed models with regard to inhalation and ingestion dose coefficients for 106Ru are examined.

  6. Fischer-Tropsch synthesis process employing a moderated ruthenium catalyst

    DOEpatents

    Abrevaya, Hayim

    1990-01-01

    A Fischer-Tropsch type process produces hydrocarbons from carbon monoxide and hydrogen using a novel catalyst comprising moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation.

  7. Fischer-Tropsch synthesis process employing a moderated ruthenium catalyst

    DOEpatents

    Abrevaya, H.

    1990-07-31

    A Fischer-Tropsch type process produces hydrocarbons from carbon monoxide and hydrogen using a novel catalyst comprising moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation. 1 fig.

  8. Electrolytic determination of ruthenium(VI) with 8-mercaptoquinoline

    SciTech Connect

    Avdienko, T.N.; Fedorova, N.G.; Sinkevich, V.V.; Suprunovich, V.I.

    1986-08-01

    The authors studied the possibility of using 8-mercaptoquinoline for the potentiometric and amperometric determination of ruthenium(VI). Previously, this reagent was recommended for the amperometric titration of ruthenium(IV) in the form of (RuCl/sub 6/)/sup 2/-; pd(II), Ir(IV), Cu(III), Au(III), and certain other metals interfere with the determination. A differential analysis of the following two-component systems was carried out: ruthenium(VI)-palladium(II); ruthenium(VI)-osmium(VI). Methods were developed for the potentiometric titration and amperometric (with the polarized electrodes) determination of ruthenium(VI) with 8-mercaptoquinoline in the presence of certain metals of the platinum group. Model mixtures, close in composition to the natural ones, and an industrial sample were analyzed.

  9. Characterization and dissolution properties of ruthenium oxides.

    PubMed

    Luxton, Todd P; Eick, Matthew J; Scheckel, Kirk G

    2011-07-01

    Ruthenium oxides (RuO(2)·1·10H(2)O and RuO(2)) have been synthesized by forced hydrolysis and oxidation of ruthenium chloride. The resulting materials were extensively characterized to determine the crystallinity, surface area, and ruthenium oxidation state. Surface charging experiments indicate a large quantity of reactive functional groups for both materials and a decrease in the acidity of the surface functional groups with crystallization of the hydrous oxide. Dissolution studies conducted in acidic and basic pH environments indicate Ru-oxides are insoluble in 0.1 M HCl and slightly soluble in 0.1 M NaOH. Oxalate and ascorbate (5 mM) promoted dissolution of RuO(2)·1·10H(2)O demonstrated an increase in dissolution rates with decreasing pH and increasing ligand surface coverage. XPS analysis of the RuO(2)·1·10H(2)O surface after ligand promoted dissolution revealed the reduction of Ru(IV) to Ru(III) indicating that both ascorbate and oxalate reductively dissolve RuO(2)·1·10H(2)O. Dissolution experiments with RuO(2) resulted in dissolution only for 5 mM oxalate at pH 3. Dissolution rates calculated for RuO(2)·1·10H(2)O and RuO(2) are compared with previously published dissolution rates for iron oxides, demonstrating an order of magnitude decrease in the oxalate and ascorbate promoted dissolution. PMID:21511266

  10. Ruthenium Vinyl Carbene Intermediates in Enyne Metathesis

    PubMed Central

    Diver, Steven T.

    2009-01-01

    This review provides an overview of ruthenium vinyl carbene reactivity as it relates to enyne metathesis. Methods for the synthesis of metathesis-active and metathesis-inactive complexes are also summarized. Some of the early hypotheses about vinyl carbene intermediates in enyne metatheses were tested in the arena of synthetic chemistry and subsequently led to mechanistic studies. In these two areas, studies from the author's labs are described. There are still many unresolved questions in enyne metathesis that trace back to vinyl carbene reactivity. Hopefully this review will stimulate further investigation into vinyl carbene reactivity which should further refine our understanding of catalytic enyne metathesis. PMID:19590747

  11. Ruthenium / aerogel nanocomposits via Atomic Layer Deposition

    SciTech Connect

    Biener, J; Baumann, T F; Wang, Y; Nelson, E J; Kucheyev, S O; Hamza, A V; Kemell, M; Ritala, M; Leskela, M

    2006-08-28

    We present a general approach to prepare metal/aerogel nanocomposites via template directed atomic layer deposition (ALD). In particular, we used a Ru ALD process consisting of alternating exposures to bis(cyclopentadienyl)ruthenium (RuCp{sub 2}) and air at 350 C to deposit metallic Ru nanoparticles on the internal surfaces of carbon and silica aerogels. The process does not affect the morphology of the aerogel template and offers excellent control over metal loading by simply adjusting the number of ALD cycles. We also discuss the limitations of our ALD approach, and suggest ways to overcome these.

  12. PROCESS FOR DECONTAMINATING THORIUM AND URANIUM WITH RESPECT TO RUTHENIUM

    DOEpatents

    Meservey, A.A.; Rainey, R.H.

    1959-10-20

    The control of ruthenium extraction in solvent-extraction processing of neutron-irradiated thorium is presented. Ruthenium is rendered organic-insoluble by the provision of sulfite or bisulfite ions in the aqueous feed solution. As a result the ruthenium remains in the aqueous phase along with other fission product and protactinium values, thorium and uranium values being extracted into the organic phase. This process is particularly applicable to the use of a nitrate-ion-deficient aqueous feed solution and to the use of tributyl phosphate as the organic extractant.

  13. Preparation and characterization of positively charged ruthenium nanoparticles.

    PubMed

    Yang, Jun; Lee, Jim Yang; Deivaraj, T C; Too, Heng-Phon

    2004-03-15

    Positively charged ruthenium nanoparticles were prepared by NaBH(4) reduction at room temperature and at pH values lower than 4.9. The ruthenium nanoparticles were characterized by zeta potential measurement, TEM, XPS, and XRD. Particles with a mean diameter of 1.8 nm and a standard deviation of 0.40 nm could be obtained under the experimental conditions. The surface charge on the particles is believed to originate from hydrated proton adsorption. The positively charged ruthenium nanoparticles could be used as the starting material for further functionalization by PVP, ethylenediamine, and dodecylamine. PMID:14972606

  14. Synergetic effect of palladium-ruthenium nanostructures for ethanol electrooxidation in alkaline media

    NASA Astrophysics Data System (ADS)

    Monyoncho, Evans A.; Ntais, Spyridon; Soares, Felipo; Woo, Tom K.; Baranova, Elena A.

    2015-08-01

    Palladium-ruthenium nanoparticles supported on carbon PdxRu1-x/C (x = 1, 0.99, 0.95, 0.90, 0.80, 0.50) were prepared using a polyol method for ethanol electrooxidation in alkaline media. The resulting bimetallic catalysts were found to be primarily a mix of Pd metal, Ru oxides and Pd oxides. Their electrocatalytic activity towards ethanol oxidation reaction (EOR) in 1M KOH was studied using cyclic voltammetry and chronoamperometry techniques. Addition of 1-10 at.% Ru to Pd not only lowers the onset oxidation potential for EOR but also produces higher current densities at lower potentials compared to Pd by itself. Thus, Pd90Ru10/C and Pd99Ru1/C provide the current densities of up to six times those of Pd/C at -0.96 V and -0.67 V vs MSE, respectively. The current density at different potentials was found to be dependent on the surface composition of PdxRu1-x/C nanostructures. Pd90Ru10/C catalyst with more surface oxides was found to be active at lower potential compared to Pd99Ru1/C with less surface oxides, which is active at higher potentials. The steady-state current densities of the two best catalysts, Pd90Ru10/C and Pd99Ru1/C, showed minimal surface deactivation from EOR intermediates/products during chronoamperometry.

  15. Biological activity of ruthenium nitrosyl complexes.

    PubMed

    Tfouni, Elia; Truzzi, Daniela Ramos; Tavares, Aline; Gomes, Anderson Jesus; Figueiredo, Leonardo Elias; Franco, Douglas Wagner

    2012-01-01

    Nitric oxide plays an important role in various biological processes, such as neurotransmission, blood pressure control, immunological responses, and antioxidant action. The control of its local concentration, which is crucial for obtaining the desired effect, can be achieved with exogenous NO-carriers. Coordination compounds, in particular ruthenium(III) and (II) amines, are good NO-captors and -deliverers. The chemical and photochemical properties of several ruthenium amine complexes as NO-carriers in vitro and in vivo have been reviewed. These nitrosyl complexes can stimulate mice hippocampus slices, promote the lowering of blood pressure in several in vitro and in vivo models, and control Trypanosoma cruzi and Leishmania major infections, and they are also effective against tumor cells in different models of cancer. These complexes can be activated chemically or photochemically, and the observed biological effects can be attributed to the presence of NO in the compound. Their efficiencies are explained on the basis of the [Ru(II)NO(+)](3+)/[Ru(II)NO(0)](2+) reduction potential, the specific rate constant for NO liberation from the [RuNO](2+) moiety, and the quantum yield of NO release. PMID:22178685

  16. Fabrication and Characterization of a Ruthenium Nitride Membrane for Electrochemical pH Sensors.

    PubMed

    Liao, Yi-Hung; Chou, Jung-Chuan

    2009-01-01

    The pH sensing and nonideal characteristics of a ruthenium nitride (RuN) sensing membrane pH sensor were investigated. RuN thin films were deposited from a 99.9% ruthenium target on p-type silicon substrates using radio frequency (r.f.) sputtering with N(2) gas. Subsequently, the nanometric structure and surface morphology of RuN thin films were determined. The sensitivity of the RuN sensing membrane pH sensor was 58.03 mV/pH, obtained from I(D)-V(G) curves with a current-voltage (I-V) measurement system in standard buffer solutions from pH 1 to pH 13 at room temperature (25 °C). Moreover, the nonideal characteristics of the RuN sensing membrane, such as temperature coefficient, drift with light influence, drift rate and hysteresis width, etc. were also investigated. Finally, the sensing characteristics of the RuN membrane were compared with titanium nitride (TiN), aluminum nitride (AlN) and silicon nitride (Si(3)N(4)) membranes. PMID:22574026

  17. Dietary pesticides (99. 99% all natural)

    SciTech Connect

    Ames, B.N.; Profet, M.; Gold, L.S. )

    1990-10-01

    The toxicological significance of exposures to synthetic chemicals is examined in the context of exposures to naturally occurring chemicals. The authors calculate that 99.99{percent} (by weight) of the pesticides in the American diet are chemicals that plants produce to defend themselves. Only 52 natural pesticides have been tested in high-dose animal cancer tests, and about half (27) are rodent carcinogens; these 27 are shown to be present in many common foods. They conclude that natural and synthetic chemicals are equally likely to be positive in animal cancer tests. They also conclude that at the low doses of most human exposures the comparative hazards of synthetic pesticide residues are insignificant.

  18. Dietary pesticides (99.99% all natural).

    PubMed Central

    Ames, B N; Profet, M; Gold, L S

    1990-01-01

    The toxicological significance of exposures to synthetic chemicals is examined in the context of exposures to naturally occurring chemicals. We calculate that 99.99% (by weight) of the pesticides in the American diet are chemicals that plants produce to defend themselves. Only 52 natural pesticides have been tested in high-dose animal cancer tests, and about half (27) are rodent carcinogens; these 27 are shown to be present in many common foods. We conclude that natural and synthetic chemicals are equally likely to be positive in animal cancer tests. We also conclude that at the low doses of most human exposures the comparative hazards of synthetic pesticide residues are insignificant. PMID:2217210

  19. Ruthenium-containing bond coats for thermal barrier coating systems

    NASA Astrophysics Data System (ADS)

    Tryon, B.; Cao, F.; Murphy, K. S.; Levi, C. G.; Pollock, T. M.

    2006-01-01

    Bond coats for zirconia-based thermal barrier coating systems applied to nickel-based superalloys are typically composed of the B2 NiAl phase. Since RuAl has the same B2 crystal structure but a melting point 400°C higher than NiAl, ruthenium-modified aluminide bond coats could provide improved system temperature capability. Creep experiments on ternary Al-Ni-Ru alloys demonstrate greatly improved creep properties with increasing ruthenium content. Processing paths for ruthenium-modified NiAl-based bond coatings have been established within the bounds of commercially available coating systems. The oxidation resistance of ruthenium-modified bond coats during thermal cycling has been examined, and potential thermal barrier coating system implications are discussed.

  20. Nonproductive Events in Ring-Closing Metathesis using Ruthenium Catalysts

    PubMed Central

    Stewart, Ian C.; Keitz, Benjamin K.; Kuhn, Kevin M.; Thomas, Renee M.

    2010-01-01

    The relative TONs of productive and nonproductive metathesis reactions of diethyl diallylmalonate are compared for eight different ruthenium-based catalysts. Nonproductive cross metathesis is proposed to involve a chain-carrying ruthenium methylidene. A second more-challenging substrate (dimethyl allylmethylallylmalonate) that forms a trisubstituted olefin product is used to further delineate the effect of catalyst structure on the relative efficiencies of these processes. A steric model is proposed to explain the observed trends. PMID:20518557

  1. Nickel/ruthenium catalyst and method for aqueous phase reactions

    DOEpatents

    Elliott, Douglas C.; Sealock, John L.

    1998-01-01

    A method of hydrogenation using a catalyst in the form of a plurality of porous particles wherein each particle is a support having nickel metal catalytic phase or reduced nickel deposited thereon in a first dispersed phase and an additional ruthenium metal deposited onto the support in a second dispersed phase. The additional ruthenium metal is effective in retarding or reducing agglomeration or sintering of the nickel metal catalytic phase thereby increasing the life time of the catalyst during hydrogenation reactions.

  2. Structural evolution of small ruthenium cluster anions

    SciTech Connect

    Waldt, Eugen; Hehn, Anna-Sophia; Ahlrichs, Reinhart; Kappes, Manfred M.; Schooss, Detlef

    2015-01-14

    The structures of ruthenium cluster anions have been investigated using a combination of trapped ion electron diffraction and density functional theory computations in the size range from eight to twenty atoms. In this size range, three different structural motifs are found: Ru{sub 8}{sup −}–Ru{sub 12}{sup −} have simple cubic structures, Ru{sub 13}{sup −}–Ru{sub 16}{sup −} form double layered hexagonal structures, and larger clusters form close packed motifs. For Ru{sub 17}{sup −}, we find hexagonal close packed stacking, whereas octahedral structures occur for Ru{sub 18}{sup −}–Ru{sub 20}{sup −}. Our calculations also predict simple cubic structures for the smaller clusters Ru{sub 4}{sup −}–Ru{sub 7}{sup −}, which were not accessible to electron diffraction measurements.

  3. A promising new thermoelectric material - Ruthenium silicide

    NASA Technical Reports Server (NTRS)

    Vining, Cronin B.; Mccormack, Joseph A.; Zoltan, Andrew; Zoltan, Leslie D.

    1991-01-01

    Experimental and theoretical efforts directed toward increasing thermoelectric figure of merit values by a factor of 2 or 3 have been encouraging in several respects. An accurate and detailed theoretical model developed for n-type silicon-germanium (SiGe) indicates that ZT values several times higher than currently available are expected under certain conditions. These new, high ZT materials are expected to be significantly different from SiGe, but not unreasonably so. Several promising candidate materials have been identified which may meet the conditions required by theory. One such candidate, ruthenium silicide, currently under development at JPL, has been estimated to have the potential to exhibit figure of merit values 4 times higher than conventional SiGe materials. Recent results are summarized.

  4. Iridium-Doped Ruthenium Oxide Catalyst for Oxygen Evolution

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I.; Narayan, Sri R.; Billings, Keith J.

    2011-01-01

    NASA requires a durable and efficient catalyst for the electrolysis of water in a polymer-electrolyte-membrane (PEM) cell. Ruthenium oxide in a slightly reduced form is known to be a very efficient catalyst for the anodic oxidation of water to oxygen, but it degrades rapidly, reducing efficiency. To combat this tendency of ruthenium oxide to change oxidation states, it is combined with iridium, which has a tendency to stabilize ruthenium oxide at oxygen evolution potentials. The novel oxygen evolution catalyst was fabricated under flowing argon in order to allow the iridium to preferentially react with oxygen from the ruthenium oxide, and not oxygen from the environment. Nanoparticulate iridium black and anhydrous ruthenium oxide are weighed out and mixed to 5 18 atomic percent. They are then heat treated at 300 C under flowing argon (in order to create an inert environment) for a minimum of 14 hours. This temperature was chosen because it is approximately the creep temperature of ruthenium oxide, and is below the sintering temperature of both materials. In general, the temperature should always be below the sintering temperature of both materials. The iridium- doped ruthenium oxide catalyst is then fabricated into a PEM-based membrane- electrode assembly (MEA), and then mounted into test cells. The result is an electrolyzer system that can sustain electrolysis at twice the current density, and at the same efficiency as commercial catalysts in the range of 100-200 mA/sq cm. At 200 mA/sq cm, this new system operates at an efficiency of 85 percent, which is 2 percent greater than commercially available catalysts. Testing has shown that this material is as stable as commercially available oxygen evolution catalysts. This means that this new catalyst can be used to regenerate fuel cell systems in space, and as a hydrogen generator on Earth.

  5. Nanoscale electron beam-induced deposition and purification of ruthenium for extreme ultraviolet lithography mask repair

    NASA Astrophysics Data System (ADS)

    Noh, J. H.; Stanford, M. G.; Lewis, B. B.; Fowlkes, J. D.; Plank, H.; Rack, P. D.

    2014-12-01

    One critical area for the adoption of extreme ultraviolet (EUV) lithography is the development of appropriate mask repair strategies. To this end, we have explored focused electron beam-induced deposition of the ruthenium capping or protective layer. Electron beam-induced deposition (EBID) was used to deposit a ruthenium capping/protective film using the liquid bis(ethylcyclopentyldienyl)ruthenium(II) precursor. The carbon to ruthenium atomic ratio in the as-deposited material was estimated to be ~9/1. Subsequent to deposition, we demonstrate an electron stimulated purification process to remove carbon by-products from the deposit. Results indicate that high-fidelity nanoscale ruthenium repairs can be realized.

  6. 99 Films on Drugs.

    ERIC Educational Resources Information Center

    Weber, David O., Ed.

    This catalog describes and evaluates 16-millimeter films about various aspects of drug use. Among the subjects covered by the 99 films are the composition and effects of different drugs, reasons why people use drugs, life in the drug culture, the problem of law enforcement, and various means of dealing with drug users. Each film is synopsized. Two…

  7. JENDL Dosimetry File 99.

    Energy Science and Technology Software Center (ESTSC)

    2001-01-22

    Version 00 JENDL/D-99 contains information for 47 nuclides and 67 reactions in the SAND-II group structure (although it was observed by RSICC that not all of the processed files are in the SAND-II group structure) and as 0K preprocessed pointwise files.

  8. Method of producing molybdenum-99

    DOEpatents

    Pitcher, Eric John

    2013-05-28

    Method of producing molybdenum-99, comprising accelerating ions by means of an accelerator; directing the ions onto a metal target so as to generate neutrons having an energy of greater than 10 MeV; directing the neutrons through a converter material comprising techentium-99 to produce a mixture comprising molybdenum-99; and, chemically extracting the molybdenum-99 from the mixture.

  9. Single Molecule Electron Transfer Process of Ruthenium Complexes.

    SciTech Connect

    Hu, Dehong; Lu, H PETER.

    2006-03-01

    Transition metal complexes such as ruthenium complexes, having metal-to-ligand charge transfer states, are extensively used in solar energy conversion and electron transfer in biological systems and at interfaces. The dynamics of metal-to-ligand charge transfer and subsequent intermolecular, intramolecular, and interfacial electron transfer processes can be highly complex and inhomogeneous, especially when molecules are involved in interactions and perturbations from heterogeneous local environments and gated by conformation fluctuations. We have employed the single-molecule spectroscopy, a powerful approach for inhomogeneous systems to study the electron transfer dynamics of ruthenium complexes. We have applied a range of statistical analysis methods to reveal nonclassical photon emission behavior of the single ruthenium complex, i.e., photon antibunching, and photophysical ground-state recovering dynamics on a microsecond time scale. The use of photon antibunching to measure phosphorescence lifetimes and single-molecule electron transfer dynamics at room temperature is demonstrated.

  10. Optimize syngas to naphtha over ruthenium catalysts

    SciTech Connect

    Stowe, R.A.; Murchison, C.B.

    1984-06-01

    In this work the authors undertake the design of a catalyst system which would efficiently utilize a stream of CO--H/sub 2/, available as a byproduct of partial combustion cracking. The H/sub 2//CO ratio of this stream was fixed by the conditions of the ethylene production process, making it desirable to reject the oxygen in CO as water rather than CO/sub 2/. A second important goal was to maximize the C/sub 2/+ selectivity in order to obtain the highest possible yield of feedstock crackable to ethylene in conventional LPG and naphtha crackers. Using an optimized potassium-promoted, aluminasupported ruthenium catalyst of practical concentration (1% Ru, 0.5% K) on a commercially available support, campaigns of over 1,000 hours on stream were achieved. Impregnation techniques which are readily scaled up were used. During these campaigns the C/sub 2/+ selectivity averaged about 90%. Of the C/sub 2/+ product, about onethird was C/sub 2/-C/sub 5/ while the C/sub 6/+ represents two-thirds.

  11. Determination of oxygen diffusion kinetics during thin film ruthenium oxidation

    SciTech Connect

    Coloma Ribera, R. Kruijs, R. W. E. van de; Yakshin, A. E.; Bijkerk, F.

    2015-08-07

    In situ X-ray reflectivity was used to reveal oxygen diffusion kinetics for thermal oxidation of polycrystalline ruthenium thin films and accurate determination of activation energies for this process. Diffusion rates in nanometer thin RuO{sub 2} films were found to show Arrhenius behaviour. However, a gradual decrease in diffusion rates was observed with oxide growth, with the activation energy increasing from about 2.1 to 2.4 eV. Further exploration of the Arrhenius pre-exponential factor for diffusion process revealed that oxidation of polycrystalline ruthenium joins the class of materials that obey the Meyer-Neldel rule.

  12. Hydrohalogenative aromatization of multiynes promoted by ruthenium alkylidene complexes.

    PubMed

    Karmakar, Rajdip; Wang, Kung-Pern; Yun, Sang Young; Mamidipalli, Phani; Lee, Daesung

    2016-06-01

    A new functionalization method of arynes promoted by a novel catalytic role of the Grubbs-type ruthenium alkylidene complex is described. Through a sequence of aryne formation followed by their halo-functionalization, various bis-1,3-diynes were directly converted to functionalized aryl chlorides, bromides and iodides in good yields in the presence of a catalytic amount of a ruthenium alkylidene complex and halogenated hydrocarbons such as CH2Cl2, CHCl3, CH2Br2, and CH2I2. The utility of this novel transformation is demonstrated by a formal synthesis of herbindole B. PMID:27145857

  13. Nickel/ruthenium catalyst and method for aqueous phase reactions

    DOEpatents

    Elliott, D.C.; Sealock, J.L.

    1998-09-29

    A method of hydrogenation is described using a catalyst in the form of a plurality of porous particles wherein each particle is a support having nickel metal catalytic phase or reduced nickel deposited thereon in a first dispersed phase and an additional ruthenium metal deposited onto the support in a second dispersed phase. The additional ruthenium metal is effective in retarding or reducing agglomeration or sintering of the nickel metal catalytic phase thereby increasing the life time of the catalyst during hydrogenation reactions. 2 figs.

  14. Technetium-99m generator system

    DOEpatents

    Mirzadeh, S.; Knapp, F.F. Jr.; Collins, E.D.

    1998-06-30

    A {sup 99}Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composition containing {sup 99}Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating {sup 99m}Tc eluted from the sorbent column. A method of preparing a concentrated solution of {sup 99m}Tc includes the general steps of: (a) providing a sorbent column loaded with a composition containing {sup 99}Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; (b) eluting the sorbent column with a salt solution to elute {sup 99m}Tc from the sorbent and to trap and concentrate the eluted {sup 99m}Tc on the ion-exchange column; and (c) eluting the concentrated {sup 99m}Tc from the ion-exchange column with a solution comprising a reductive complexing agent. 1 fig.

  15. Technetium-99m generator system

    DOEpatents

    Mirzadeh, Saed; Knapp, Jr., Furn F.; Collins, Emory D.

    1998-01-01

    A .sup.99 Mo/.sup.99m Tc generator system includes a sorbent column loaded with a composition containing .sup.99 Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating .sup.99m Tc eluted from the sorbent column. A method of preparing a concentrated solution of .sup.99m Tc includes the general steps of: a. providing a sorbent column loaded with a composition containing .sup.99 Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; b. eluting the sorbent column with a salt solution to elute .sup.99m Tc from the sorbent and to trap and concentrate the eluted .sup.99m Tc on the ion-exchange column; and c. eluting the concentrated .sup.99m Tc from the ion-exchange column with a solution comprising a reductive complexing agent.

  16. Adsorption of ruthenium red to phospholipid membranes.

    PubMed Central

    Voelker, D; Smejtek, P

    1996-01-01

    We have measured the distribution of the hexavalent ruthenium red cation (RuR) between water and phospholipid membranes, have shown the critical importance of membrane negative surface charge for RuR binding, and determined the association constant of RuR for different phospholipid bilayers. The studies were performed with liposomes made of mixtures of zwitterionic L-alpha-phosphatidylcholine (PC), and one of the negatively charged phospholipids: L-alpha-phosphatidylserine (PS), L-alpha-phosphatidylinositol (PI), or L-alpha-phosphatidylglycerol (PG). Lipid composition of PC:PX membranes was 1:0, 19:1, 9:1, and 4:1. Liposomes were processed using freeze-and-thaw treatment, and their size distribution was characterized by light scattering and electron microscopy. Experimental distribution isotherms of RuR obtained by ultracentrifugation and spectrophotometry can be reproduced with the Langmuir-Stern-Grahame model, assuming that RuR behaves in the diffuse double layer as an ion with effective valency < 6. In terms of this model, PC-PS, PC-PI, and PC-PG membranes were found to be electrostatically equivalent and the intrinsic association constants of RuR were obtained. RuR has highest affinity to PS-containing membranes; its association constant for PC-PI and PC-PG membranes is about 5 times smaller than that for PC-PS membranes. From the comparison of RuR binding to mixed negatively charged phospholipid membranes and RuR binding to sarcoplasmic reticulum (SR), we conclude that the low-affinity RuR binding sites may indeed be associated with the lipid bilayer of SR. PMID:8789099

  17. Improvement of ruthenium based decarboxylation of carboxylic acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The removal of oxygen atoms from biobased carboxylic acids is an attractive route to provide the drop in replacement feedstocks that industry needs to continue to provide high performance products. Through the use of ruthenium catalysis, an efficient method where this process can be accomplished on ...

  18. Molecular dinitrogen complexes of ruthenium(II) porphyrins

    SciTech Connect

    Camenzind, M.J.; James, B.R.; Dolphin, D.; Sparapany, J.W.; Ibers, J.A.

    1988-08-24

    The existence of both mono- and bis(nitrogen) complexes of ruthenium have been previously established. Details on a series of complexes are presented herein, and results of an x-ray crystallographic study of Ru(TMP) (THF) (N/sub 2/) are reported. 30 references, 4 tables.

  19. Photodissociation Spectroscopy of Ruthenium Polypyridyl Complexes in Vacuo

    NASA Astrophysics Data System (ADS)

    Xu, Shuang; Smith, James; Weber, J. Mathias

    Photoelectrochemical water oxidation is a direct way to produce solar fuels from renewable sources. Since this reaction has a high reaction barrier, a cost-effective catalyst is necessary. Ruthenium polypyridyl complexes are promising catalysts for water oxidation. However, the mechanism of catalytic action is not well understood. One major difficulty of a mechanistic understanding is the complexity of reactive solutions under turnover conditions. To circumvent this problem, we applied electronic photodissociation spectroscopy in the UV and visible spectral range to a series of mass selected ruthenium polypyridyl complex ions in vacuo. The ions in this work are of the form [RuII-L]2+, where RuII represents ruthenium(II)-bipyridine-terpyridine, a prototype catalyst belonging to the ruthenium-polypyridyl family. By varying the ligand L, we were able to study the ligand influence on the photophysical properties of the complex. The cases where L = (H2O)1 , 2 , 3 are of particular interest because they are directly related to an intermediate in the catalytic cycle for water oxidation. Our experiment in vacuo is an essential complement to experiments in solution and provides unique information for understanding the photophysics and photochemistry of these complexes on a molecular level.

  20. Tailoring NO donors metallopharmaceuticals: ruthenium nitrosyl ammines and aliphatic tetraazamacrocycles.

    PubMed

    Tfouni, E; Doro, F G; Figueiredo, L E; Pereira, J C M; Metzker, G; Franco, D W

    2010-01-01

    The discovery of the involvement of nitric oxide (NO) in several physiological and pathophysiological processes launched a spectacular increase in studies in areas such as chemistry, biochemistry, and pharmacology. As a consequence, the development of NO donors or scavengers for regulation of its concentration and bioavailability in vivo is required. In this sense, ruthenium nitrosyl ammines and aliphatic tetraazamacrocyles have attracted a lot of attention due to their unique chemical properties. These complexes are water soluble and stable in solution, not to mention that they can deliver NO when photochemically or chemically activated by the reduction of the coordinated nitrosonium (NO+). The tuning of the energies of the charge transfer bands, the redox potential, and the specific rate constants of NO liberation, in both solution and matrices, is desirable for the achievement of selective NO delivery to biological targets, hence making the ruthenium ammines and aliphatic tetraazamacrocyles a quite versatile platform for biological application purposes. These ruthenium nitrosyls have shown to be active in firing neurons in mouse hippocampus, performing redox reactions in mitochondria, acting in blood pressure control, exhibiting cytotoxic activities against trypanosomatids (T.cruzi and L.major) and tumor cells. This tailoring approach is explored here, being heavily supported by the accumulated knowledge on the chemistry and photochemistry of ruthenium complexes, which allows NO donors/scavengers systems to be custom made designed. PMID:20846113

  1. Molecular Models of Ruthenium(II) Organometallic Complexes

    ERIC Educational Resources Information Center

    Coleman, William F.

    2007-01-01

    This article presents the featured molecules for the month of March, which appear in the paper by Ozerov, Fafard, and Hoffman, and which are related to the study of the reactions of a number of "piano stool" complexes of ruthenium(II). The synthesis of compound 2a offers students an alternative to the preparation of ferrocene if they are only…

  2. Ruthenium-catalyzed C–H activation of thioxanthones

    PubMed Central

    Wagner, Danny

    2015-01-01

    Summary Thioxanthones – being readily available in one step from thiosalicylic acid and arenes – were used in ruthenium-catalyzed C–H-activation reaction to produce 1-mono- or 1,8-disubstituted thioxanthones in good to excellent yields. Scope and limitation of this reaction are presented. PMID:25977717

  3. Arsenate Adsorption On Ruthenium Oxides: A Spectroscopic And Kinetic Investigation

    EPA Science Inventory

    Arsenate adsorption on amorphous (RuO2•1.1H2O) and crystalline (RuO2) ruthenium oxides was evaluated using spectroscopic and kinetic methods to elucidate the adsorption mechanism. Extended X-ray absorption fine structure spectroscopy (EXAFS) was ...

  4. PRECIPITATION OF ZIRCONIUM, NIOBIUM, AND RUTHENIUM FROM AQUEOUS SOLUTIONS

    DOEpatents

    Wilson, A.S.

    1958-08-12

    An improvement on the"head end process" for decontaminating dissolver solutions of their Zr, Ni. and Ru values. The process consists in adding a water soluble symmetrical dialkyl ketone. e.g. acetone, before the formation of the manganese dioxide precipitate. The effect is that upon digestion, the ruthenium oxide does not volatilize, but is carried on the manganese dioxide precipitate.

  5. Block by ruthenium red of the ryanodine-activated calcium release channel of skeletal muscle

    PubMed Central

    1993-01-01

    The effects of ruthenium red and the related compounds tetraamine palladium (4APd) and tetraamine platinum (4APt) were studied on the ryanodine activated Ca2+ release channel reconstituted in planar bilayers with the immunoaffinity purified ryanodine receptor. Ruthenium red, applied at submicromolar concentrations to the myoplasmic side (cis), induced an all-or-none flickery block of the ryanodine activated channel. The blocking effect was strongly voltage dependent, as large positive potentials that favored the movement of ruthenium red into the channel conduction pore produced stronger block. The half dissociation constants (Kd) for ruthenium red block of the 500 pS channel were 0.22, 0.38, and 0.62 microM, at +100, +80, and +60 mV, respectively. Multiple ruthenium red molecules seemed to be involved in the inhibition, because a Hill coefficient of close to 2 was obtained from the dose response curve. The half dissociation constant of ruthenium red block of the lower conductance state of the ryanodine activated channel (250 pS) was higher (Kd = 0.82 microM at +100 mV), while the Hill coefficient remained approximately the same (nH = 2.7). Ruthenium red block of the channel was highly asymmetric, as trans ruthenium red produced a different blocking effect. The blocking and unblocking events (induced by cis ruthenium red) can be resolved at the single channel level at a cutoff frequency of 2 kHz. The closing rate of the channel in the presence of ruthenium red increased linearly with ruthenium red concentration, and the unblocking rate of the channel was independent of ruthenium red concentrations. This suggests that ruthenium red block of the channel occurred via a simple blocking mechanism. The on-rate of ruthenium red binding to the channel was 1.32 x 10(9) M-1 s-1, and the off-rate of ruthenium red binding was 0.75 x 10(3) s-1 at +60 mV, in the presence of 200 nM ryanodine. The two related compounds, 4APd and 4APt, blocked the channel in a similar way to that

  6. Spectroscopic investigation on the interaction of ruthenium complexes with tumor specific lectin, jacalin.

    PubMed

    Ayaz Ahmed, Khan Behlol; Reshma, Elamvazhuthi; Mariappan, Mariappan; Anbazhagan, Veerappan

    2015-02-25

    Several ruthenium complexes are regarded as anticancer agents and considered as an alternative to the widely used platinum complexes. Owing to the preferential interaction of jacalin with tumor-associated T-antigen, we report the interaction of jacalin with four ruthenium complex namely, tris(1,10-phenanthroline)ruthenium(II)chloride, bis(1,10-phenanthroline)(N-[1,10]phenanthrolin-5-yl-pyrenylmethanimine)ruthenium(II)chloride, bis(1,10-phenanthroline)(dipyrido[3,2-a:2',3'-c]-phenazine)ruthenium(II)chloride, bis(1,10-phenanthroline)(11-(9-acridinyl)dipyrido[3,2-a:2',3'-c]phenazine)ruthenium(II) chloride. Fluorescence spectroscopic analysis revealed that the ruthenium complexes strongly quenched the intrinsic fluorescence of jacalin through a static quenching procedure, and a non-radiative energy transfer occurred within the molecules. Association constants obtained for the interaction of different ruthenium complexes with jacalin are in the order of 10(5) M(-1), which is in the same range as those obtained for the interaction of lectin with carbohydrate and hydrophobic ligand. Each subunit of the tetrameric jacalin binds one ruthenium complex, and the stoichiometry is found to be unaffected by the presence of the specific sugar, galactose. In addition, agglutination activity of jacalin is largely unaffected by the presence of the ruthenium complexes, indicating that the binding sites for the carbohydrate and the ruthenium complexes are different. These results suggest that the development of lectin-ruthenium complex conjugate would be feasible to target malignant cells in chemo-therapeutics. PMID:25306128

  7. Synthesis of PVP-stabilized ruthenium colloids with low boiling point alcohols.

    PubMed

    Zhang, Yuqing; Yu, Jiulong; Niu, Haijun; Liu, Hanfan

    2007-09-15

    A route to the preparation of poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized ruthenium colloids by refluxing ruthenium(III) chloride in low boiling point alcohols was developed. Deep purple colloids with shuttle-like ruthenium particles were also synthesized. XPS measurement verified the nanoparticles were in the metallic state. The morphology of metal nanoparticles was characterized by UV-visible absorption spectrophotometry, TEM and XRD. PMID:17568601

  8. Determination of ruthenium and iridium in anode coatings by atomic-absorption spectroscopy.

    PubMed

    Harrington, D E; Bramstedt, W R

    A method is described for the determination of ruthenium and iridium coated on an electrode surface. The coating is chemically removed from the electrode by fusion with alkali, and the resulting solution prepared for analysis. Interelement interferences are eliminated by using a titanium-potassium matrix solution as a releasing agent. Recovery and precision data are given for ruthenium and iridium. The AAS determination of ruthenium compares favourably with a standard colorimetric method. PMID:18961657

  9. Spectroscopic investigation on the interaction of ruthenium complexes with tumor specific lectin, jacalin

    NASA Astrophysics Data System (ADS)

    Ayaz Ahmed, Khan Behlol; Reshma, Elamvazhuthi; Mariappan, Mariappan; Anbazhagan, Veerappan

    2015-02-01

    Several ruthenium complexes are regarded as anticancer agents and considered as an alternative to the widely used platinum complexes. Owing to the preferential interaction of jacalin with tumor-associated T-antigen, we report the interaction of jacalin with four ruthenium complex namely, tris(1,10-phenanthroline)ruthenium(II)chloride, bis(1,10-phenanthroline)(N-[1,10]phenanthrolin-5-yl-pyrenylmethanimine)ruthenium(II)chloride, bis(1,10-phenanthroline)(dipyrido[3,2-a:2‧,3‧-c]-phenazine)ruthenium(II)chloride, bis(1,10-phenanthroline)(11-(9-acridinyl)dipyrido[3,2-a:2‧,3‧-c]phenazine)ruthenium(II) chloride. Fluorescence spectroscopic analysis revealed that the ruthenium complexes strongly quenched the intrinsic fluorescence of jacalin through a static quenching procedure, and a non-radiative energy transfer occurred within the molecules. Association constants obtained for the interaction of different ruthenium complexes with jacalin are in the order of 105 M-1, which is in the same range as those obtained for the interaction of lectin with carbohydrate and hydrophobic ligand. Each subunit of the tetrameric jacalin binds one ruthenium complex, and the stoichiometry is found to be unaffected by the presence of the specific sugar, galactose. In addition, agglutination activity of jacalin is largely unaffected by the presence of the ruthenium complexes, indicating that the binding sites for the carbohydrate and the ruthenium complexes are different. These results suggest that the development of lectin-ruthenium complex conjugate would be feasible to target malignant cells in chemo-therapeutics.

  10. Flow-injection chemiluminescent determination of cefprozil using Tris (2,2'-bipyridyl) ruthenium (II)-permanganate system.

    PubMed

    Alarfaj, Nawal A; Abd El-Razeq, Sawsan A

    2006-06-16

    A rapid and sensitive chemiluminescence (CL) method using flow-injection (FI) has been developed for the determination of a second generation cephalosporin, cefprozil. The method is based on the CL reaction of cefprozil with acidic potassium permanganate and tris (2,2'-bipyridyl) ruthenium (II), Ru (bipy)3(2+). The CL intensity is greatly enhanced when quinine sulfate is used as a sensitizer. After optimization of the different experimental parameters, a calibration graph was obtained over a concentration range of 0.1-3.0 microg ml(-1) with minimum detectability of 0.005 microgml(-1) (S/N=3). The correlation coefficient was 0.9998 (n=6) with a relative standard deviation (%R.S.D.) of 1.63% for 2.0 microgml(-1). The proposed method was successfully applied to commercial tablets. The average percentage recovery (n=6) was 99.9+/-1.40. PMID:16682164

  11. Ruthenium-97 hepatobiliary agents for delayed studies of the bilary tract I: Ru-97 PIPIDA: concise communication

    SciTech Connect

    Schachner, E.R.; Gil, M.C.; Atkins, H.L.; Som, P.; Srivastava, S.C.; Badia, J.; Sacker, D.F.; Fairchild, R.G.; Richards, P.

    1981-04-01

    Failure of early diagnosis of biliary atresia results in the development of cirrhosis and death. Commonly used hepatobiliary agents are not ideal for follow-up studies because of their unfavorable physical properties or short half-life. The excellent physical properties of Ru-97 should overcome these limitations. Therefore, Ru-97 PIPIDA (N,..cap alpha..-(p-isopropyl acetanilide) iminoacetic acid) is being investigated as a potential hepatobiliary agent that would allow an improved diagnosis of the disease. Ruthenium-97 PIPIDA and Tc-99m PIPIDA showed similar blood clearance rates in dogs. Ru-97 PIPIDA scintigrams in dogs showed early uptake in liver and gallbladder and slow excretion through the gastrointestinal tract. Biodistribution studies were performed in normal rats and rats with biliary obstruction. The findings suggest that Ru-97 PIPIDA should be useful for delayed studies ( 1 to 3 days) of the biliary tract.

  12. Surface and sub-surface thermal oxidation of thin ruthenium films

    SciTech Connect

    Coloma Ribera, R.; Kruijs, R. W. E. van de; Yakshin, A. E.; Bijkerk, F.; Kokke, S.; Zoethout, E.

    2014-09-29

    A mixed 2D (film) and 3D (nano-column) growth of ruthenium oxide has been experimentally observed for thermally oxidized polycrystalline ruthenium thin films. Furthermore, in situ x-ray reflectivity upon annealing allowed the detection of 2D film growth as two separate layers consisting of low density and high density oxides. Nano-columns grow at the surface of the low density oxide layer, with the growth rate being limited by diffusion of ruthenium through the formed oxide film. Simultaneously, with the growth of the columns, sub-surface high density oxide continues to grow limited by diffusion of oxygen or ruthenium through the oxide film.

  13. Thermodynamic data bases for multivalent elements: An example for ruthenium

    SciTech Connect

    Rard, J.A.

    1987-11-01

    A careful consideration and understanding of fundamental chemistry, thermodynamics, and kinetics is absolutely essential when modeling predominance regions and solubility behavior of elements that exhibit a wide range of valence states. Examples of this are given using the ruthenium-water system at 298.15 K, for which a critically assessed thermochemical data base is available. Ruthenium exhibits the widest range of known aqueous solution valence states. Known solid anhydrous binary oxides of ruthenium are crystalline RuO/sub 2/, RuO/sub 4/, and possibly RuO/sub 3/ (thin film), and known hydroxides/hydrated oxides (all amorphous) are Ru(OH)/sub 3/ . H/sub 2/O, RuO/sub 2/ . 2H/sub 2/O, RuO/sub 2/ . H/sub 2/O, and a poorly characterized Ru(V) hydrous oxide. Although the other oxides, hydroxides, and hydrous oxides are generally obtained as precipitates from aqueous solutions, they are thermodynamically unstable with regard to RuO/sub 2/(cr) formation. Characterized aqueous species of ruthenium include RuO/sub 4/ (which slowly oxidizes water and which dissociates as a weak acid), RuO/sub 4//sup -/ and RuO/sub 4//sup 2 -/ (which probably contain lesser amounts of RuO/sub 3/(OH)/sub 2//sup -/ and RuO/sub 3/(OH)/sub 2//sup 2 -/, respectively, and other species), Ru(OH)/sub 2//sup 2 +/, Ru/sub 4/(OH)/sub 12//sup 4 +/, Ru(OH)/sub 4/, Ru/sup 3 +/, Ru(OH)/sup 2 +/, Ru(OH)/sub 2//sup +/, Ru/sup 2 +/, and some hydroxytetramers with formal ruthenium valences of 3.75 greater than or equal to Z greater than or equal to 2.0. Potential pH diagrams of the predominance regions change significantly with concentration due to polymerization/depolymerization reactions. Failure to consider the known chemistry of ruthenium can yield large differences in predicted solubilities.

  14. Structure sensitive adsorption of hydrogen on ruthenium and ruthenium-silver catalysts supported on silica

    SciTech Connect

    Kumar, N.

    1999-02-12

    Supported metal catalysts typically consist of particles with sizes less than 10 nm, and because of the small crystallite size, low coordination number sites (edges and corners) represent a significant fraction of all surface sites. Furthermore, it has been demonstrated that adsorption rates can be much greater at these low coordination sites than on basal plane sites. What has not been generally appreciated, however, is that preferential adsorption at edge and corner sites may explain the mechanism by which a promoter, or the addition of a second metal to form a bimetallic, can alter the selectivity and rate of reaction. For example, the measurements of hydrogen adsorption onto supported Ru-Ag catalysts show marked decreases in the amount of hydrogen adsorbed relative to the amount adsorbed on Ru catalysts. Although it is known that Ag does not dissociatively adsorb hydrogen, this decrease cannot be explained by a simple one-to-one site blocking mechanism unless Ag preferentially populates edges and corners, thereby reducing the number of Ru edge sites. Indeed, Monte Carlo simulations of Ru-Group IB metal catalysts predict that Group IB metal atoms preferentially populate corner and edge sites of ruthenium crystals. This evidence, taken together, suggests that adsorption occurs preferentially at Ru corner and edge sites, which act as portals onto basal planes. A model based on this portal theory for hydrogen adsorption onto supported ruthenium bimetallic catalysts has been developed using a rate equation approach. Specifically, the model accounts for the following features: (1) preferential adsorption through portals, (2) basal plane site-energy multiplicity, and (3) hydrogen spillover onto the support. A comparison of model predictions with experiment is presented for different concentration of Ag in Ru-Ag catalysts. The portal model of hydrogen adsorption can explain the observed decreased in the amount of hydrogen adsorbed on Ru-Ag catalysts. The model can be

  15. Preparation, stability, and photoreactivity of thiolato ruthenium polypyridyl complexes: Can cysteine derivatives protect ruthenium-based anticancer complexes?

    PubMed

    van Rixel, Vincent H S; Busemann, Anja; Göttle, Adrien J; Bonnet, Sylvestre

    2015-09-01

    Ruthenium polypyridyl complexes may act as light-activatable anticancer prodrugs provided that they are protected by well-coordinated ligands that i) prevent coordination of other biomolecules to the metal center in the dark and ii) can be removed by visible light irradiation. In this paper, the use of monodentate thiol ligands RSH as light-cleavable protecting groups for the ruthenium complex [Ru(tpy)(bpy)(OH2)](PF6)2 ([1](PF6)2; tpy=2,2';6',2″-terpyridine, bpy=2,2'-bypyridine), is investigated. The reaction of [1](2+) with RSH=H2Cys (L-cysteine), H2Acys (N-acetyl-L-cysteine), and HAcysMe (N-acetyl-L-cysteine methyl ester), is studied by UV-visible spectroscopy, NMR spectroscopy, and mass spectrometry. Coordination of the monodentate thiol ligands to the ruthenium complex takes place upon heating to 353 K, but full conversion to the protected complex [Ru(tpy)(bpy)(SR)]PF6 is only possible when a large excess of ligand is used. Isolation and characterization of the two new thiolato complexes [Ru(tpy)(bpy)(κS-HCys)]PF6 ([2]PF6) and [Ru(tpy)(bpy)(κS-HAcys)]PF6 ([3]PF6) is reported. [3]PF6 shows a metal-to-ligand charge-transfer absorption band that is red shifted (λmax=492 nm in water) compared to its methionine analogue [Ru(tpy)(bpy)(κS-HAmet)](Cl)2 ([5](Cl)2, λmax=452 nm; HAmet=N-acetyl-methionine). In the dark the thiolate ligand coordinated to ruthenium is oxidized even by traces of oxygen, which first leads to the sulfenato, sulfinato, and disulfide ruthenium complexes, and finally to the formation of the aqua complex [1](2+). [3]PF6 showed slow photosubstitution of the thiolate ligand by water under blue light irradiation, together with faster photooxidation of the thiolate ligand compared to dark conditions. The use of thiol vs. thioether monodentate ligands is discussed for the protection of anticancer ruthenium-based prodrugs. PMID:26187140

  16. Complex of transferrin with ruthenium for medical applications

    DOEpatents

    Richards, P.; Srivastava, S.C.; Meinken, G.E.

    1984-05-15

    A novel ruthenium-transferrin complex is disclosed which is prepared by reacting iron-free human transferrin dissolved in a sodium acetate solution at pH 7 with ruthenium by heating at about 40 C for about 2 hours. The complex is purified by means of gel chromotography with pH 7 sodium acetate as eluent. The mono- or di-metal complex produced can be used in nuclear medicine in the diagnosis and/or treatment of tumors and abscesses. Comparative results with Ga-67-citrate, which is the most widely used tumor-localizing agent in nuclear medicine, indicate increased sensitivity of detection and greater tumor uptake with the Ru-transferrin complex. No Drawings

  17. Complex of transferrin with ruthenium for medical applications

    DOEpatents

    Richards, Powell; Srivastava, Suresh C.; Meinken, George E.

    1984-05-15

    A novel Ruthenium-transferrin complex, prepared by reacting iron-free human transferrin dissolved in a sodium acetate solution at pH 7 with ruthenium by heating at about 40.degree. C. for about 2 hours, and purifying said complex by means of gel chromotography with pH 7 sodium acetate as eluent. The mono- or di-metal complex produced can be used in nuclear medicine in the diagnosis and/or treatment of tumors and abscesses. Comparative results with Ga-67-citrate, which is the most widely used tumor-localizing agent in nuclear medicine, indicate increased sensitivity of detection and greater tumor uptake with the Ru-transferrin complex.

  18. Hydrogen and oxygen adsorption stoichiometries on silica supported ruthenium nanoparticles

    SciTech Connect

    Berthoud, Romain; Delichere, Pierre; Gajan, David; Lukens, Wayne; Pelzer, Katrin; Basset, Jean-Marie; Candy, Jean-Pierre; Coperet, Christophe

    2008-12-01

    Treatment under H{sub 2} at 300 C of Ru(COD)(COT) dispersed on silica yields 2 nm ruthenium nanoparticles, [Ru{sub p}/SiO{sub 2}], according to EXAFS, HRTEM and XPS. H{sub 2} adsorption measurements on [Ru{sub p}/SiO{sub 2}] in the absence of O{sub 2} show that Ru particles adsorb up to ca. 2 H per surface ruthenium atoms (2H/Ru{sub s}) on various samples; this technique can therefore be used to measure the dispersion of Ru particles. In contrast, O{sub 2} adsorption on [Ru{sub p}/SiO{sub 2}] leads to a partial oxidation of the bulk at 25 C, to RuO{sub 2} at 200 C and to sintering upon further reduction under H{sub 2}, showing that O{sub 2} adsorption cannot be used to measure the dispersion of Ru particles.

  19. Alkyne Hydroacylation: Switching Regioselectivity by Tandem Ruthenium Catalysis

    PubMed Central

    Chen, Qing-An; Cruz, Faben A.; Dong, Vy M.

    2015-01-01

    By using tandem ruthenium-catalysis, internal alkynes can be coupled with aldehydes for the synthesis of β,γ-unsaturated ketones. The catalyst promotes alkyne transformations with high regioselectivity, with examples that include the differentiation of a methyl versus ethyl substituent on the alkyne. Mechanistic studies suggest that the regioselectivity results from a selective allene formation that is governed by allylic strain. PMID:25608143

  20. Characteristics of a promising new thermoelectric material - Ruthenium silicide

    NASA Technical Reports Server (NTRS)

    Ohta, Toshitaka; Vining, Cronin B.; Allevato, Camillo E.

    1991-01-01

    A preliminary study on arc-melted samples has indicated that ruthenium silicide has the potential to obtain figure-of-merit values four times higher than that of conventional silicon-germanium material. In order to realize the high figure-of-merit values, high-quality crystal from the melt is needed. A Bridgman-like method has been employed and has realized much better crystals than arc-melted ones.

  1. Ruthenium catalyzed hydrogenation of aldehyde with synthesis gas.

    PubMed

    Takahashi, Kohei; Nozaki, Kyoko

    2014-11-21

    The hydrogenation of aldehyde utilizing synthesis gas as a dihydrogen source was examined with various ruthenium catalysts, among which Ru-cyclopentadienone complexes (Shvo-type catalysts) exhibited higher activity than others. DFT calculations proved that the exchange of coordinated carbon monoxide by dihydrogen is relatively preferable in Shvo-type catalysts compared to others, which is a pre-equilibrium for the generation of the hydrogenation-active species. PMID:25372182

  2. Hydrogenation of Aldehydes Catalyzed by an Available Ruthenium Complex.

    PubMed

    Tan, Xuefeng; Wang, Guozhen; Zhu, Ziyue; Ren, Conghui; Zhou, Jinping; Lv, Hui; Zhang, Xiaoyong; Chung, Lung Wa; Zhang, Lina; Zhang, Xumu

    2016-04-01

    A readily available ruthenium(II) catalyst was developed for the catalytic hydrogenation of aldehydes with a TON (turnover number) up to 340000. It can be performed without base and solvent, showing highly industrial potential. High chemoselectivity can be achieved in the presence of alkenyl and ketone groups. Further application of this protocol in glucose reduction showed good efficiency. Theoretical studies revealed that the rate-determining step is the hydrogenation step, not the carboxylate-assisted H2 activation step. PMID:26974348

  3. STS-99 Crew Insignia

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The STS-99 crew members designed the flight insignia for the Shuttle Radar Topography Mission (SRTM), the most ambitious Earth mapping mission to date. Two radar anternas, one located in the Shuttle bay and the other located on the end of a 60-meter deployable mast, was used during the mission to map Earth's features. The goal was to provide a 3-dimensional topographic map of the world's surface up to the Arctic and Antarctic Circles. In the patch, the clear portion of Earth illustrates the radar beams penetrating its cloudy atmosphere and the unique understanding of the home planet that is provided by space travel. The grid on Earth reflects the mapping character of the SRTM mission. The patch depicts the Space Shuttle Endeavour orbiting Earth in a star spangled universe. The rainbow along Earth's horizon resembles an orbital sunrise. The crew deems the bright colors of the rainbow as symbolic of the bright future ahead because of human beings' venturing into space. The crew of six launched aboard the Space Shuttle Endeavor on February 11, 2000 and completed 222 hours of around the clock radar mapping gathering enough information to fill more than 20,000 CDs.

  4. The development of a selective ruthenium Fischer-Tropsch catalyst

    SciTech Connect

    Abrevaya, H.

    1989-01-01

    A new stable Fischer-Tropsch catalyst with very high selectivity to distillate fuels and with low light ends production was developed. This catalyst, which was made by a reverse micelle technique, contains 2.8% (by weight) ruthenium in the form of 4--6 nm particles on alumina and a proprietary modifier. The new modified ruthenium catalyst did not noticeably deactivate during 814 hours at about 80% CO conversion, 2H{sub 2}:1 CO feed ratio, 208{degree}C at inlet, 62 atm and 150 gas hourly space velocity. In order to determine the catalyst's tolerance, the operational severity was increased between 814 hours and 1700 hours by increasing the temperature and space velocity to 225{degree}C at inlet and to 205 hr{sup {minus}1}, respectively. A deactivation rate of about 0.016%/hour was measured under these more severe conditions at about 70% conversion level. These results with the new modified ruthenium catalyst compare favorably with those reported for the two commercial Sasol processes. The Arge process makes approximately 38% distillate fuel with 14--18% light ends, while the Synthol process makes about 48% distillate with 38% light ends. 82 refs., 360 figs., 66 tabs.

  5. Behaviour of ruthenium dioxide particles in borosilicate glasses and melts

    NASA Astrophysics Data System (ADS)

    Pflieger, Rachel; Lefebvre, Leila; Malki, Mohammed; Allix, Mathieu; Grandjean, Agnès

    2009-06-01

    Ruthenium-glass systems are formed during the vitrification of nuclear waste. They are also widely used in micro-electronics because of their unique electrical properties. However, the interaction of this element with the glass matrix remains poorly understood. This work focuses on a RuO 2 particles-nuclear alumino-borosilicate glass system in which the electrical conductivity is known to vary considerably with the RuO 2 content and to become electronic above about 0.5-0.7 vol.% RuO 2 [R. Pflieger, M. Malki, Y. Guari, J. Larionova, A. Grandjean, J. Am. Ceram. Soc., accepted for publication]. Some RuO 2 segregation was observed in SEM/TEM investigations but no continuous chain of RuO 2 particles could be seen. Electron relays between the particles are then necessary for a low-rate percolation, such as the nanoclusters suggested by Adachi et al. [K. Adachi, S. Iida, K. Hayashi, J. Mater. Res. 9 (7) (1994) 1866; K. Adachi, H. Kuno, J. Am. Ceram. Soc. 83 (10) (2000) 2441], which could consist in dissolved ruthenium. Indeed, several observations made here clearly indicate the presence of dissolved ruthenium in the glass matrix, like the modification of the glass density in presence of RuO 2 particles or the diffusion-limited growth of RuO 2 particles in the melt.

  6. Electrochemical deposition of conducting ruthenium oxide films from solution

    SciTech Connect

    Anderson, D.P.; Warren, L.F.

    1984-02-01

    In the last decade, ruthenium oxide, RuO /sub x/ (x less than or equal to 2), has been used extensively as the active anode electrocatalyst constituent for Cl/sub 2/ and O/sub 2/ evolution reactions, in chlorate production, and in metal electrowinning from mixed chloride-sulfate solutions. More recently, this material has been incorporated in several light-induced water electrolysis schemes and apparently possesses the ability to inhibit CdS photocorrosion by acting as a hole scavenger. The numerous applications for this catalyst material certainly warrant further studies of its electrochemical properties on a variety of substrates, e.g., semiconductors. The lack of a simple technique for controlled deposition of ruthenium oxide onto conducting substrates prompted us to investigate an electrochemical approach to this problem. We describe here a new way to electrochemically deposit conducting films of hydrated ruthenium oxide from an aqueous solution of the benzeneruthenium (II)aqua complex. The films slowly dissolve in aqueous electrolytes upon potential cycling, yet appear to be catalytic with regards to water oxidation.

  7. 99. 99% Al/ 6063 Alloy Co-extruded beam chamber

    SciTech Connect

    Ishimaru, H.; Narushima, K.; Kanazawa, K.

    1988-09-30

    In an electron storage ring, synchrotron radiation causes stimulated gas desorption from the vacuum chamber wall. It raises the operating pressure far above the ultrahigh vacuum range needed for long beam lifetimes. In order to determine an ideal material for low dynamic gas desorption we have studied the properties of co-extruded 99.99%Al/ 6063 alloy. (AIP)

  8. Factors determining the consumption of ruthenium during electrosynthesis of sodium hypochlorite with the use of ruthenium oxide-titanium anodes

    SciTech Connect

    Klement'eva, V.S.; Kubasov, V.L.; Lambrev, V.G.; Uzbekov, A.A.

    1985-09-01

    The authors studied the rate of destruction of the active coating as a function of the electrolysis conditions during electrochemical production of sodium hypochlorite. Corrosion tests were carried out on specimens made by the thermochemical method, in an electrochemical cell without a diaphragm; the method used was based on neutron activation analysis. It was shown that losses of ruthenium can be lowered by conducting the electrolysis at low temperatures, higher current densities, and moderately low hypochlorite concentrations. However, the increase of current density may raise the ROTA potential above the critical value, when rapid anode failure is possible. It was also shown that under conditions such that the critical ROTA potential is not reached sodium hypochlorite solutions of fairly high concentrations can be obtained with a low comsumption of ruthenium, which is not possible with the use of many other anode materials.

  9. Ruthenium on chitosan: A recyclable heterogeneous catalyst for aqueous hydration of nitriles to amides

    EPA Science Inventory

    Ruthenium has been immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with ruthenium chloride and has been utilized for the oxidation of nitriles to amides; the hydration of nitriles occurs in high yield and excellent selectivity, which procee...

  10. Ruthenium(II)-Catalyzed Decarboxylative C-H Activation: Versatile Routes to meta-Alkenylated Arenes.

    PubMed

    Kumar, N Y Phani; Bechtoldt, Alexander; Raghuvanshi, Keshav; Ackermann, Lutz

    2016-06-01

    Ruthenium(II) bis(carboxylate)s proved highly effective for two decarboxylative C-H alkenylation strategies. The decarboxylation proceeded efficiently at rather low temperatures. The unique versatility of the decarboxylative ruthenium(II) catalysis is reflected in the oxidative olefinations with alkenes as well as the redox-neutral hydroarylations of alkynes. PMID:26996920

  11. Ruthenium-Catalyzed C-H Alkynylation of Aromatic Amides with Hypervalent Iodine-Alkyne Reagents.

    PubMed

    Boobalan, Ramadoss; Gandeepan, Parthasarathy; Cheng, Chien-Hong

    2016-07-15

    An efficient C-H activation method for the ortho alkynylation of aromatic N-methoxyamides with hypervalent iodine-alkyne reagent using a ruthenium catalyst is described. The reaction proceeds under mild reaction conditions with broad substrate scope. A possible catalytic cycle involving a ruthenium carboxylate assisted C-H bond cleavage is proposed from the preliminary mechanistic evidence. PMID:27357724

  12. Magnetic Silica-Supported Ruthenium Nanoparticles: An Efficient Catalyst for Transfer Hydrogenation of Carbonyl Compounds

    EPA Science Inventory

    One-pot synthesis of ruthenium nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium nano particles immobilization; the hydration of nitriles and transfer hydrogenation of carbonyl compounds occurs in hi...

  13. Investigation of Ruthenium Electrodes for (Ba,Sr)TiO3 Thin Films

    NASA Astrophysics Data System (ADS)

    Joo, Jae-Hyun; Seon, Jeong-Min; Jeon, Yoo-Chan; Oh, Ki-Young; Roh, Jae-Sung; Kim, Jae-Jeong; Choi, Jin-Tae

    1998-06-01

    Ru/(Ba, Sr)TiO3(BST)/Ru capacitors were fabricated on TiN/Ti/Poly-Si/SiO2/Si substrate by sputtering technique. The effects of the bottom ruthenium electrode, deposited at various temperatures, on the characteristics of Ru/BST/Ru capacitor were intensively studied. Sputtered ruthenium films were grown in a columnar structure with a grain size ˜30 nm. With an increasing deposition temperature of ruthenium films, the (002) preferred orientation and grain size of ruthenium films gradually increased while the residual compressive stress in the ruthenium films was reduced. The surface of ruthenium films was oxidized to form RuOx on its surface during the deposition of BST films, which dramatically changed the surface morphology of ruthenium films and affected the characteristics of Ru/BST/Ru capacitor. In this work, the electrical properties of Ru/BST/Ru capacitors are explained with an emphasis on the surface morphology and residual stress of ruthenium films.

  14. Thermochemistry of Ruthenium Oxyhydroxide Species and Their Impact on Volatile Speciations in Severe Nuclear Accident Conditions.

    PubMed

    Miradji, Faoulat; Virot, François; Souvi, Sidi; Cantrel, Laurent; Louis, Florent; Vallet, Valérie

    2016-02-01

    Literature thermodynamic data of ruthenium oxyhydroxides reveal large uncertainties in some of the standard enthalpies of formation, motivating the use of high-level relativistic correlated quantum chemical methods to reduce the level of discrepancies. Reaction energies leading to the formation of all possible oxyhydroxide species RuOx(OH)y(H2O)z have been calculated for a series of reactions combining DFT (TPSSh-5%HF) geometries and partition functions, CCSD(T) energies extrapolated to the complete basis set limits. The highly accurate ab initio thermodynamic data were used as input data of thermodynamic equilibrium computations to derive the speciation of gaseous ruthenium species in the temperature, pressure and concentration conditions of severe nuclear accidents occurring in pressurized water reactors. At temperatures lower than 1000 K, gaseous ruthenium tetraoxide is the dominating species, between 1000 and 2000 K ruthenium trioxide becomes preponderant, whereas at higher temperatures gaseous ruthenium oxide, dioxide and even Ru in gaseous phase are formed. Although earlier studies predicted the formation of oxyhydroxides in significant quantities, the use of highly accurate ab initio thermodynamic data for ruthenium gaseous species leads to a more reliable inventory of gaseous ruthenium species in which gaseous oxyhydroxide ruthenium molecules are formed only in negligible amounts. PMID:26789932

  15. Volatilities of ruthenium, iodine, and technetium on calcining fission product nitrate wastes

    SciTech Connect

    Rimshaw, S.J.; Case, F.N.

    1980-01-01

    Various high-level nitrate wastes were subjected to formic acid denitration. Formic acid reacts with the nitrate anion to yield noncondensable, inert gases according to the following equation: 4 HCOOH + 2 HNO/sub 3/ ..-->.. N/sub 2/O + 4 CO/sub 2/ + 5 H/sub 2/O. These gases can be scrubbed free of /sup 106/Ru, /sup 131/I, and /sup 99/Tc radioactivities prior to elimination from the plant by passage through HEPA filters. The formation of deleterious NO/sub x/ is avoided. Moreover, formic acid reduces ruthenium to a lower valence state with a sharp reduction in RuO/sub 4/ volatility during subsequent calcination of the pretreated waste. It is shown that a minimum of 3% of RuO/sub 4/ in an off-gas stream reacts with Davison silica gel (Grade 40) to give a fine RuO/sub 2/ aerosol having a particle size of 0.5 ..mu... This RuO/sub 2/ aerosol passes through water or weak acid scrub solutions but is trapped by a caustic scrub solution. Iodine volatilizes almost completely on calcining an acidic waste, and the iodine volatility increases with increasing calcination temperature. On calcining an alkaline sodium nitrate waste the iodine volatility is about an order of magnitude lower, with a relatively low iodine volatility of 0.39% at a calcination temperature of 250/sup 0/C and a moderate volatility of 9.5% at 600/sup 0/C. Volatilities of /sup 99/Tc were generally <1% on calcining acidic or basic wastes at temperatures of 250 to 600/sup 0/C. Data are presented to indicate that /sup 99/Tc concentrates in the alkaline sodium nitrate supernatant waste, with approx. 10 mg /sup 99/Tc being associated with each curie of /sup 137/Cs present in the waste. It is shown that lutidine (2,4 dimethyl-pyridine) extracts Tc(VII) quantitatively from alkaline supernatant wastes. The distribution coefficient (K/sub D/) for Tc(VII) going into the organic phase in the above system is 102 for a simulated West Valley waste and 191 for a simulated Savannah River Plant (SRP) waste.

  16. Chemical state of ruthenium submonolayers on a Pt(1 1 1) electrode

    NASA Astrophysics Data System (ADS)

    Kim, H.; Rabelo de Moraes, I.; Tremiliosi-Filho, G.; Haasch, R.; Wieckowski, A.

    2001-03-01

    Oxidation states of ruthenium on a Pt(1 1 1)/Ru electrode were investigated by X-ray photoelectron spectroscopy. Ruthenium was added to platinum by electrochemical deposition methods: spontaneous deposition and electrolysis. Depending on the electrode potential, deposition conditions, and presence/absence of methanol in solution, metallic ruthenium (3d 5/2 core-level binding energy of 280.3 eV), RuO 2 (280.9 eV), and RuO 3 (282.8 eV) were found on the surface. After correlating ruthenium valence states to methanol oxidation reactivity, we concluded that the presence of a Ru metallic phase - covered by a weakly bonded Ru oxidation precursor - was a prerequisite for effective methanol oxidation electrocatalysis. This precursor was most likely "activated" water supplying the oxygen needed for transformation of surface CO to CO 2 at the edge of ruthenium islands on the Pt substrate.

  17. New cholescintigraphic agent: ruthenium-97-DISIDA

    SciTech Connect

    Zanzi, I.; Srivastava, S.C.; Meinken, G,E.; Robeson, W.; Mausner, L.F.; Fairchild, R.G.; Margouleff, D.

    1986-06-01

    These studies demonstrate the first application of Ru-97-DISIDA in human subjects. High quality images were obtained. Scintigraphic findings in patients with hepatobiliary disorders were consistent with the biodistribution data obtained in experinmental animals and with other imaging procedures and clinical findings. Administration of Ru-97-DISIDA I.V. and of a solid test meal labeled with Tc-99m-Sulfur Colloid allowed simulateneous detection and quantification of deodenogastric reflux and determination of the gastric emptying rate. This represents an advantage as compared to the currently used techniques which necessitate two separate studies if a solid meal is used, or would mandate a liquid meal for a simultaneous study. The excellent nuclear decay characteristics of Ru-97 (tl/2 69.6 h, gamma 216 keV, 86%, no betas) permit delayed study of the hepatobiliary system with considerably less radiation exposure than I-131 Rose Bengal and with a marked improvement in image quality. 5 refs., 3 figs., 3 tabs.

  18. Antiparasitic activities of novel ruthenium/lapachol complexes.

    PubMed

    Barbosa, Marília I F; Corrêa, Rodrigo S; de Oliveira, Katia Mara; Rodrigues, Claudia; Ellena, Javier; Nascimento, Otaciro R; Rocha, Vinícius P C; Nonato, Fabiana R; Macedo, Taís S; Barbosa-Filho, José Maria; Soares, Milena B P; Batista, Alzir A

    2014-07-01

    The present study describes the synthesis, characterization, antileishmanial and antiplasmodial activities of novel diimine/(2,2'-bipyridine (bipy), 1,10-phenanthroline (phen), 4,4'-methylbipyridine (Me-bipy) and 4,4'-methoxybipyridine (MeO-bipy)/phosphine/ruthenium(II) complexes containing lapachol (Lap, 2-hydroxy-3-(3-33 methyl-2-buthenyl)-1,4-naphthoquinone) as bidentate ligand. The [Ru(Lap)(PPh3)2(bipy)]PF6 (1), [Ru(Lap)(PPh3)2(Me-bipy)]PF6 (2), [Ru(Lap)(PPh3)2(MeO-bipy)]PF6(3) and[Ru(Lap)(PPh3)2(phen)]PF6 (4) complexes, PPh3=triphenylphospine, were synthesized from the reactions of cis-[RuCl2(PPh3)2(X-bipy)] or cis-[RuCl2(PPh3)2(phen)], with lapachol. The [RuCl2(Lap)(dppb)] (5) [dppb=1,4-bis(diphenylphosphine)butane] was synthesized from the mer-[RuCl3(dppb)(H2O)] complex. The complexes were characterized by elemental analysis, molar conductivity, infrared and UV-vis spectroscopy, (31)P{(1)H} and (1)H NMR, and cyclic voltammetry. The Ru(III) complex, [RuCl2(Lap)(dppb)], was also characterized by the EPR technique. The structure of the complexes [Ru(Lap)(PPh3)2(bipy)]PF6 and [RuCl2(Lap)(dppb)] was elucidated by X-ray diffraction. The evaluation of the antiparasitic activities of the complexes against Leishmania amazonensis and Plasmodium falciparum demonstrated that lapachol-ruthenium complexes are more potent than the free lapachol. The [RuCl2(Lap)(dppb)] complex is the most potent and selective antiparasitic compound among the five new ruthenium complexes studied in this work, exhibiting an activity comparable to the reference drugs. PMID:24727183

  19. Novel Ruthenium Sensitizers with a Phenothiazine Conjugated Bipyridyl Ligand for High-Efficiency Dye-Sensitized Solar Cells.

    PubMed

    She, Zhijie; Cheng, Yangyang; Zhang, Luoqiang; Li, Xiaoyu; Wu, Di; Guo, Qiang; Lan, Jingbo; Wang, Ruilin; You, Jingsong

    2015-12-23

    Two efficient ruthenium sensitizers with a phenothiazine-modified bipyridine as an ancillary ligand, coded SCZ-1 and SCZ-2, have been developed as dyes in dye-sensitized solar cells (DSSCs). Both sensitizers exhibit low-energy metal-to-ligand charge transfer (MLCT) bands centered at 539 nm with high molar extinction coefficients of 1.77 × 10(4) M(-1) cm(-1) for SCZ-1 and 1.66 × 10(4) M(-1) cm(-1) for SCZ-2, which are significantly higher than the corresponding value for the reference N719 (1.27 × 10(4) M(-1) cm(-1)), indicating that the light-harvesting capacity of ruthenium sensitizers can be reinforced by introducing phenothiazine moieties into the bipyridine ligand. Under AM 1.5G irradiation (100 mW cm(-2)), SCZ-1 and SCZ-2 sensitized DSSC devices show impressive power conversion efficiencies (PCE) up to 10.4% by using of iodide-based electrolytes, which exceeds that of N719 (9.9%) under the same conditions. Both of the open circuit voltage (VOC) and fill factor (FF) of SCZ-sensitized solar cells approximate to those of N719-sensitized cell. The relatively higher efficiencies of the SCZ-sensitized cells than that of N719-sensitized cell come from their higher short-circuit photocurrent density (JSC), which may be mainly attributed to the high absorption coefficient. The absorption spectrum and device efficiency of SCZ-1 are both quite close to those of SCZ-2, suggesting that the difference in alkyl chains on the N atom of phenothiazine is not a decisive factor in affecting the photovoltaic performance of dyes. PMID:26624527

  20. Ruthenium Behavior at Phase Separation of Borosilicate Glass-12259

    SciTech Connect

    Enokida, Youichi; Sawada, Kayo

    2012-07-01

    The Rokkasho reprocessing plant (RRP) located in Aomori, Japan, vitrifies high level waste (HLW) into a borosilicate glass. The HLW is generated from the reprocessing of spent fuel and contains ruthenium (Ru) and other platinum group metals (PGMs). Based on the recent consequences after a huge earthquake that occurred in Japan, a hypothetical blackout was postulated for the RRP to address additional safety analysis requirements. During a prolonged blackout, the borosilicate glass could phase separate due to cooling of the glass in the melter. The Ru present in the glass matrix could migrate into separate phases and impact the durability of the borosilicate glass. The durability of the glass is important for quality assurance and performance assessment of the vitrified HLW. A fundamental study was performed at an independent university to understand the impact of a prolonged blackout. Simulated HLW glasses were prepared for the RRP, and the Ru behavior in phase separated glasses was studied. The simulated HLW glasses contained nonradioactive elements and PGMs. The glass compositions were then altered to enhance the formation of the phase-separated glasses when subjected to thermal treatment at 700 deg. C for 24 hours. The synthesized simulated glasses contained 1.1 % Ru by weight as ruthenium dioxide (RuO{sub 2}). A portion of the RuO{sub 2} formed needle-shaped crystals in the glass specimens. After the thermal treatment, the glass specimen had separated into two phases. One of the two phases was a B{sub 2}O{sub 3} rich phase, and the other phase was a SiO{sub 2} rich phase. The majority of the chemical species in the B{sub 2}O{sub 3} rich phase was leached away with the Material Characterization Center-3 (MCC-3) protocol standardized by the Pacific Northwest National Laboratory using an aqueous low-concentrated nitric acid solution, but the leaching of the Ru fraction was very limited; less than 1% of the original Ru content. The Ru leaching was much less than

  1. Jahn-Teller driven perpendicular magnetocrystalline anisotropy in metastable ruthenium

    NASA Astrophysics Data System (ADS)

    Odkhuu, Dorj; Rhim, S. H.; Park, Noejung; Nakamura, Kohji; Hong, Soon Cheol

    2015-01-01

    A metastable phase of body-centered-tetragonal ruthenium (bct Ru) is identified to exhibit a large perpendicular magnetocrystalline anisotropy (PMCA), whose energy EMCA is as large as 150 μ eV /atom , which is two orders of magnitude greater than those of 3 d magnetic metals. Further investigation over the range of tetragonal distortion suggests that the appearance of magnetism in the bct Ru is governed by the Jahn-Teller spit eg orbitals. Moreover, from band analysis, MCA is mainly determined by an interplay between two eg states, dx2-y2 and dz2 states, as a result of level reversal associated with tetragonal distortion.

  2. Binuclear ruthenium(II) complexes for amyloid fibrils recognition

    NASA Astrophysics Data System (ADS)

    Hanczyc, Piotr

    2014-12-01

    Metal-organic compounds represent a unique class of biomarkers with promising photophysical properties useful for imaging. Here interactions of insulin fibrils with two binuclear complexes [μ-(11,11‧-bidppz)(phen)4Ru2]4+ (1) and [μ-C4(cpdppz)(phen)4Ru2]4+ (2) are studied by linear dichroism (LD) and fluorescence. These ruthenium(II) compounds could provide a new generation of amyloid binding chromophores with long lived lifetimes, good luminescence quantum yields for the bound molecules and photo-stability useful in multiphoton luminescence imaging.

  3. Progress in doping of ruthenium silicide (Ru2Si3)

    NASA Technical Reports Server (NTRS)

    Vining, C. B.; Allevato, C. E.

    1992-01-01

    Ruthenium silicide is currently under development as a promising thermoelectric material suitable for space power applications. Key to realizing the potentially high figure of merit values of this material is the development of appropriate doping techniques. In this study, manganese and iridium have been identified as useful p- and n-type dopants, respectively. Resistivity values have been reduced by more than 3 orders of magnitude. Anomalous Hall effect results, however, complicate interpretation of some of the results and further effort is required to achieve optimum doping levels.

  4. Thermal properties of ruthenium alkylidene-polymerized dicyclopentadiene

    PubMed Central

    Vidavsky, Yuval; Navon, Yotam; Ginzburg, Yakov; Gottlieb, Moshe

    2015-01-01

    Summary Differential scanning calorimetry (DSC) analysis of ring opening methatesis polymerization (ROMP) derived polydicyclopentadiene (PDCPD) revealed an unexpected thermal behavior. A recurring exothermic signal can be observed in the DSC analysis after an elapsed time period. This exothermic signal was found to be proportional to the resting period and was accompanied by a constant increase in the glass-transition temperature. We hypothesize that a relaxation mechanism within the cross-linked scaffold, together with a long-lived stable ruthenium alkylidene species are responsible for the observed phenomenon. PMID:26425203

  5. Sensitization of NO-Releasing Ruthenium Complexes to Visible Light.

    PubMed

    Becker, Tobias; Kupfer, Stephan; Wolfram, Martin; Görls, Helmar; Schubert, Ulrich S; Anslyn, Eric V; Dietzek, Benjamin; Gräfe, Stefanie; Schiller, Alexander

    2015-10-26

    We report a combined spectroscopical-theoretical investigation on the photosensitization of transition metal nitrosyl complexes. For this purpose, ruthenium nitrosyl complexes based on tetradentate biscarboxamide ligands were synthesized. A crystal structure analysis of a lithium-based ligand intermediate is described. The Ru complexes have been characterized regarding their photophysical and nitric oxide (NO) releasing properties. Quantum chemical calculations have been performed to unravel the influence of the biscarboxamide ligand frame with respect to the molecular electronic properties of the NO-releasing pathway. A quantitative measure for the ligand design within photosensitized Ru complexes is introduced and evaluated spectroscopically and theoretically by using time-dependent density functional theory. PMID:26394612

  6. The solubility of hydrogen in rhodium, ruthenium, iridium and nickel.

    NASA Technical Reports Server (NTRS)

    Mclellan, R. B.; Oates, W. A.

    1973-01-01

    The temperature variation of the solubility of hydrogen in rhodium, ruthenium, iridium, and nickel in equilibrium with H2 gas at 1 atm pressure has been measured by a technique involving saturating the solvent metal with hydrogen, quenching, and analyzing in resultant solid solutions. The solubilities determined are small (atom fraction of H is in the range from 0.0005 to 0.00001, and the results are consistent with the simple quasi-regular model for dilute interstitial solid solutions. The relative partial enthalpy and excess entropy of the dissolved hydrogen atoms have been calculated from the solubility data and compared with well-known correlations between these quantities.

  7. Metalorganic Chemical Vapor Deposition of Ruthenium-Doped Diamond like Carbon Films

    NASA Technical Reports Server (NTRS)

    Sunkara, M. K.; Ueno, M.; Lian, G.; Dickey, E. C.

    2001-01-01

    We investigated metalorganic precursor deposition using a Microwave Electron Cyclotron Resonance (ECR) plasma for depositing metal-doped diamondlike carbon films. Specifically, the deposition of ruthenium doped diamondlike carbon films was investigated using the decomposition of a novel ruthenium precursor, Bis(ethylcyclopentadienyl)-ruthenium (Ru(C5H4C2H5)2). The ruthenium precursor was introduced close to the substrate stage. The substrate was independently biased using an applied RF power. Films were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Four Point Probe. The conductivity of the films deposited using ruthenium precursor showed strong dependency on the deposition parameters such as pressure. Ruthenium doped sample showed the presence of diamond crystallites with an average size of approx. 3 nm while un-doped diamondlike carbon sample showed the presence of diamond crystallites with an average size of 11 nm. TEM results showed that ruthenium was atomically dispersed within the amorphous carbon network in the films.

  8. Effect of ionic strength on ruthenium CMP in H2O2-based slurries

    NASA Astrophysics Data System (ADS)

    Jiang, Liang; He, Yongyong; Li, Yuzhuo; Luo, Jianbin

    2014-10-01

    With the development of ultra-large scale integrated circuits, ruthenium has been selected as one of the most promising barrier metals for copper interconnects to replace traditional Ta/TaN bilayer. This paper mainly investigated the effect of ionic strength on the chemical mechanical polishing performance of ruthenium in H2O2-based slurries. The results show that, the ruthenium removal rate (RR) increases with the increasing concentration of H2O2 due to the formation of ruthenium oxides like Ru(OH)3, RuO2·2H2O and even RuO42-; additionally, the ruthenium RR can be further enhanced with the increase of K+ ionic strength. It is revealed that the added K+ can intensify the electrochemical reactions between H2O2 and the ruthenium surface by increasing the conductivity, meanwhile can also result in the neutralization of the zeta potentials of both silica particles and the ruthenium surface, and thus can lead to the decrease of the electrostatic repulsive force and the increase of the mechanical abrasion intensity between silica particles and the ruthenium surface. Therefore, the ruthenium RR increases with the increase of K+ ionic strength. Furthermore, the effects of K+ ionic strength on the material removal rate (MRR) selectivity of Ru vs. Cu and the galvanic corrosion of Cu/Ru couple are studied. It is found that, in order to achieve higher MRR selectivity than 1.0, KNO3 is preferred for the K+ source; and with H2O2 as the oxidizer, copper galvanic corrosion problem can be effectively suppressed.

  9. In Situ Catalyst Modification in Atom Transfer Radical Reactions with Ruthenium Benzylidene Complexes.

    PubMed

    Lee, Juneyoung; Grandner, Jessica M; Engle, Keary M; Houk, K N; Grubbs, Robert H

    2016-06-01

    Ruthenium benzylidene complexes are well-known as olefin metathesis catalysts. Several reports have demonstrated the ability of these catalysts to also facilitate atom transfer radical (ATR) reactions, such as atom transfer radical addition (ATRA) and atom transfer radical polymerization (ATRP). However, while the mechanism of olefin metathesis with ruthenium benzylidenes has been well-studied, the mechanism by which ruthenium benzylidenes promote ATR reactions remains unknown. To probe this question, we have analyzed seven different ruthenium benzylidene complexes for ATR reactivity. Kinetic studies by (1)H NMR revealed that ruthenium benzylidene complexes are rapidly converted into new ATRA-active, metathesis-inactive species under typical ATRA conditions. When ruthenium benzylidene complexes were activated prior to substrate addition, the resulting activated species exhibited enhanced kinetic reactivity in ATRA with no significant difference in overall product yield compared to the original complexes. Even at low temperature, where the original intact complexes did not catalyze the reaction, preactivated catalysts successfully reacted. Only the ruthenium benzylidene complexes that could be rapidly transformed into ATRA-active species could successfully catalyze ATRP, whereas other complexes preferred redox-initiated free radical polymerization. Kinetic measurements along with additional mechanistic and computational studies show that a metathesis-inactive ruthenium species, generated in situ from the ruthenium benzylidene complexes, is the active catalyst in ATR reactions. Based on data from (1) H, (13)C, and (31)P NMR spectroscopy and X-ray crystallography, we suspect that this ATRA-active species is a RuxCly(PCy3)z complex. PMID:27186790

  10. Dynamics of the contact between a ruthenium surface with a single nanoasperity and a flat ruthenium surface: Molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    de Oliveira, Alan Barros; Fortini, Andrea; Buldyrev, Sergey V.; Srolovitz, David

    2011-04-01

    We study the dynamics of the contact between a pair of surfaces (with properties designed to mimic ruthenium) via molecular dynamics simulations. In particular, we study the contact between a ruthenium surface with a single nanoasperity and a flat ruthenium surface. The results of such simulations suggest that contact behavior is highly variable. The goal of this study is to investigate the source and degree of this variability. We find that during compression, the behavior of the contact force displacement curves is reproducible, while during contact separation, the behavior is highly variable. Examination of the contact surfaces suggests that two separation mechanisms are in operation and give rise to this variability. One mechanism corresponds to the formation of a bridge between the two surfaces that plastically stretches as the surfaces are drawn apart and eventually separate in shear. This leads to a morphology after separation in which there are opposing asperities on the two surfaces. This plastic separation/bridge formation mechanism leads to a large work of separation. The other mechanism is a more brittle-like mode in which a crack propagates across the base of the asperity (slightly below the asperity/substrate junction) leading to most of the asperity on one surface or the other after separation and a slight depression facing this asperity on the opposing surface. This failure mode corresponds to a smaller work of separation. This failure mode corresponds to a smaller work of separation. Furthermore, contacts made from materials that exhibit predominantly brittle-like behavior will tend to require lower work of separation than those made from ductile-like contact materials.

  11. The appearance of the outflow apparatus of the eye after staining with ruthenium red.

    PubMed

    Grierson, I; Lee, W R; Abraham, S

    1977-10-01

    The outflow apparatus from adult baboon and rabbit eyes was stained with the inorganic dye ruthenium red. The ruthenium reaction product coated the surface of the trabecular meshwork cells and the canalicular endothelial cells. Deposits also impregnated the various connective tissue elements within the trabeculae and the extracellular spaces of the endothelial meshwork. A fine fibrillar network could also be identified with ruthenium red and this was present in the trabecular cores and the extracellular spaces of the endothelial meshwork. It was considered that the fibrillar network may represent a matrix of glycosaminoglycans and glycoproteins. The significance of these materials in relation to aqueous outflow was discussed. PMID:71846

  12. Effect of temperature annealing on capacitive and structural properties of hydrous ruthenium oxides

    NASA Astrophysics Data System (ADS)

    Fang, Wei-Chuan; Huang, Jin-Hua; Chen, Li-Chyong; Su, Yuh-Long Oliver; Chen, Kuei-Hsien

    The structure-property relationships of hydrous ruthenium oxides, fabricated by electro deposition on Ti foil, were investigated with different annealing conditions. The annealing temperature was found to play an important role in affecting the electrochemical performance of the annealed hydrous ruthenium oxides. The results indicate that annealing hydrous ruthenium oxide at its crystallization threshold temperature, ∼200 °C, may help to create suitable nanostructure in the oxide that supports the establishment of interpenetrating percolation paths for balanced electron and proton conduction, thereby improving the capacitive response of the oxide dramatically. This finding is useful for fabrication of electrodes with enhanced electrochemical performance for application in microsupercapacitor.

  13. Internal stresses and structure of electrolytic films of ruthenium, rhodium, and palladium

    SciTech Connect

    Medyanik, V.N.

    1986-01-01

    Films of ruthenium, rhodium, and palladium are used as targets in nuclear physics experiments in the form of metal foils. The authors investigate how the current density and the concentration of metal in the electrolyte influence the internal stresses, the grain size, and the texture of electrolytic films of ruthenium, rhodium, and palladium. The grain size of rhodium and palladium films increases with the current density, but for ruthenium there is no exact relationship. The increase in grain size in films of rhodium and palladium leads to a reduction in the internal stresses.

  14. Dinuclear Ruthenium(III)-Ruthenium(IV) Complexes, Having a Doubly Oxido-Bridged and Acetato- or Nitrato-Capped Framework.

    PubMed

    Suzuki, Tomoyo; Suzuki, Yutaka; Kawamoto, Tatsuya; Miyamoto, Ryo; Nanbu, Shinkoh; Nagao, Hirotaka

    2016-07-18

    Dinuclear ruthenium complexes in a mixed-valence state of Ru(III)-Ru(IV), having a doubly oxido-bridged and acetato- or nitrato-capped framework, [{Ru(III,IV)(ebpma)}2(μ-O)2(μ-L)](PF6)2 [ebpma = ethylbis(2-pyridylmethyl)amine; L = CH3COO(-) (1), NO3(-) (2)], were synthesized. In aqueous solutions, the diruthenium complex 1 showed multiple redox processes accompanied by proton transfers depending on the pH. The protonated complex of 1, which is described as 1H+, was obtained. PMID:27341408

  15. Cellular delivery of pyrenyl-arene ruthenium complexes by a water-soluble arene ruthenium metalla-cage.

    PubMed

    Furrer, Mona Anca; Schmitt, Frédéric; Wiederkehr, Michaël; Juillerat-Jeanneret, Lucienne; Therrien, Bruno

    2012-06-28

    Three pyrenyl-arene ruthenium complexes (M(1)-M(3)) of the general formula [Ru(η(6)-arene-pyrenyl)Cl(2)(pta)] (pta = 1,3,5-triaza-7-phosphaadamantane) have been synthesised and characterised. Prior to the coordination to ruthenium, pyrene was connected to the arene ligand via an alkane chain containing different functional groups: ester (L(1)), ether (L(2)) and amide (L(3)), respectively. Furthermore, the pyrenyl moieties of the M(n) complexes were encapsulated within the hydrophobic cavity of the water soluble metalla-cage, [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) (tpt = 2,4,6-tri-(pyridin-4-yl)-1,3,5-triazine; donq = 5,8-dioxydo-1,4-naphthoquinonato), while the arene ruthenium end was pointing out of the cage, thus giving rise to the corresponding host-guest systems [M(n)⊂Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) ([M(n)⊂cage](6+)). The antitumor activity of the pyrenyl-arene ruthenium complexes (M(n)) and the corresponding host-guest systems [M(n)⊂cage][CF(3)SO(3)](6) were evaluated in vitro in different types of human cancer cell lines (A549, A2780, A2780cisR, Me300 and HeLa). Complex M(2), which contains an ether group within the alkane chain, demonstrated at least a 10 times higher cytotoxicity than the reference compound [Ru(η(6)-p-cymene)Cl(2)(pta)] (RAPTA-C). All host-guest systems [M(n)⊂cage](6+) showed good anticancer activity with IC(50) values ranging from 2 to 8 μM after 72 h exposure. The fluorescence of the pyrenyl moiety allowed the monitoring of the cellular uptake and revealed an increase of uptake by a factor two of the M(2) complex when encapsulated in the metalla-cage [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+). PMID:22506276

  16. Synthesis of cubic ruthenium nitride by reactive pulsed laser ablation

    NASA Astrophysics Data System (ADS)

    Moreno-Armenta, M. G.; Diaz, J.; Martinez-Ruiz, A.; Soto, G.

    2007-10-01

    The recent synthesis of platinum nitride opens the possibility of novel platinum-group metal nitrides to exist. In this work we report the synthesis of ruthenium nitride by reactive pulsed laser ablation. Several plausible structures have been evaluated by ab initio calculations using the full potential linearized augmented plane wave method, in order to investigate the ruthenium nitride structural and electronic properties. In fact, the predicted symmetry of stoichiometric RuN matches the experimental diffraction data. RuN crystallizes with NaCl-type structure at room temperature with cell-parameter somewhat larger than predicted by calculations. However we found a marginal chemical strength in these nitrides. The material is destroyed by mild acid and basic solutions. Under annealing RuN decomposes abruptly for temperatures beyond 100 °C. Since the thermal stability correlates directly with the mechanical properties our finding cast doubts than the latter transition metal nitrides can be ultra-hard materials at ambient conditions.

  17. Fischer-Tropsch reaction studies with supported ruthenium catalysts

    SciTech Connect

    Everson, R.C.; Mulder, H. )

    1993-09-01

    An investigation was undertaken to examine the production of low molecular weight alkenes (C[sub 2][sup =] to C[sup =][sub 4]) and high molecular weight hydrocarbons (C[sub 5]+) from synthesis gas in a fixed bed reactor with supported ruthenium catalyst. The catalyst used consisted of 0.5% ruthenium on gamma-alumina with a 43% metal dispersion. An experimental reactor consisting of a single 12.5-mm-diameter stainless-steel tube with catalyst packings up to 1 m long, surrounded by an aluminium block with heating elements and an outer insulating ceramic block was used. The effect of temperature, synthesis gas composition (CO/H[sub 2]), weight hourly space velocity (WHSV), and bed length on carbon monoxide conversion and selectivity was examined and results are reported. The presence of secondary reactions consisting of hydrogenation and chain growth involving alkenes along the reactor bed was observed. These reactions favour the formation of alkanes and high molecular weight hydrocarbons. The alkene to alkane ratio in the product can be increased by restricting the hydrogenation reaction with the use of a synthesis gas mixture with a high carbon monoxide to hydrogen ratio.

  18. Multistate Switches: Ruthenium Alkynyl-Dihydroazulene/Vinylheptafulvene Conjugates.

    PubMed

    Vlasceanu, Alexandru; Andersen, Cecilie L; Parker, Christian R; Hammerich, Ole; Morsing, Thorbjørn J; Jevric, Martyn; Lindbaek Broman, Søren; Kadziola, Anders; Nielsen, Mogens Brøndsted

    2016-05-23

    Multimode molecular switches incorporating distinct and independently addressable functional components have potential applications as advanced switches and logic gates for molecular electronics and memory storage devices. Herein, we describe the synthesis and characterization of four switches based on the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermoswitch pair functionalized with the ruthenium-based Cp*(dppe)Ru ([Ru*]) metal complex (dppe=1,2-bis(diphenylphosphino)ethane; Cp*=pentamethylcyclopentadienyl). The [Ru*]-DHA conjugates can potentially exist in six different states accessible by alternation between DHA/VHF, Ru(II) /Ru(III) , and alkynyl/vinylidene, which can be individually stimulated by using light/heat, oxidation/reduction, and acid/base. Access to the full range of states was found to be strongly dependent on the electronic communication between the metal center and the organic photoswitch in these [Ru*]-DHA conjugates. Detailed electrochemical, spectroscopic (UV/Vis, IR, NMR), and X-ray crystallographic studies indeed reveal significant electronic interactions between the two moieties. When in direct conjugation, the ruthenium metal center was found to quench the photochemical ring-opening of DHA, which in one case could be restored by protonation or oxidation, allowing conversion to the VHF state. PMID:27114110

  19. Photoreactivity of a quantum dot-ruthenium nitrosyl conjugate.

    PubMed

    Franco, Lilian Pereira; Cicillini, Simone Aparecida; Biazzotto, Juliana Cristina; Schiavon, Marco A; Mikhailovsky, Alexander; Burks, Peter; Garcia, John; Ford, Peter C; da Silva, Roberto Santana

    2014-12-26

    We describe the use of cadmium telluride quantum dots (CdTe QDs) as antennas for the photosensitization of nitric oxide release from a ruthenium nitrosyl complex with visible light excitation. The CdTe QDs were capped with mercaptopropionic acid to make them water-soluble, and the ruthenium nitrosyl complex was cis-[Ru(NO)(4-ampy)(bpy)2](3+) (Ru-NO; bpy is 2,2'-bipyridine, and 4-ampy is 4-aminopyridine). Solutions of these two components demonstrated concentration-dependent quenching of the QD photoluminescence (PL) as well as photoinduced release of NO from Ru-NO when irradiated by 530 nm light. A NO release enhancement of ∼8 times resulting from this association was observed under longer wavelength excitation in visible light range. The dynamics of the quenching determined by both PL and transient absorption measurements were probed by ultrafast flash photolysis. A charge transfer mechanism is proposed to explain the quenching of the QD excited states as well as the photosensitized release of NO from Ru-NO. PMID:25405612

  20. New nitric oxide donors based on ruthenium complexes.

    PubMed

    Lunardi, C N; da Silva, R S; Bendhack, L M

    2009-01-01

    Nitric oxide (NO) donors produce NO-related activity when applied to biological systems. Among its diverse functions, NO has been implicated in vascular smooth muscle relaxation. Despite the great importance of NO in biological systems, its pharmacological and physiological studies have been limited due to its high reactivity and short half-life. In this review we will focus on our recent investigations of nitrosyl ruthenium complexes as NO-delivery agents and their effects on vascular smooth muscle cell relaxation. The high affinity of ruthenium for NO is a marked feature of its chemistry. The main signaling pathway responsible for the vascular relaxation induced by NO involves the activation of soluble guanylyl-cyclase, with subsequent accumulation of cGMP and activation of cGMP-dependent protein kinase. This in turn can activate several proteins such as K+ channels as well as induce vasodilatation by a decrease in cytosolic Ca2+. Oxidative stress and associated oxidative damage are mediators of vascular damage in several cardiovascular diseases, including hypertension. The increased production of the superoxide anion (O2-) by the vascular wall has been observed in different animal models of hypertension. Vascular relaxation to the endogenous NO-related response or to NO released from NO deliverers is impaired in vessels from renal hypertensive (2K-1C) rats. A growing amount of evidence supports the possibility that increased NO inactivation by excess O2- may account for the decreased NO bioavailability and vascular dysfunction in hypertension. PMID:19219301

  1. Thiocyanate linkage isomerism in a ruthenium polypyridyl complex.

    PubMed

    Brewster, Timothy P; Ding, Wendu; Schley, Nathan D; Hazari, Nilay; Batista, Victor S; Crabtree, Robert H

    2011-12-01

    Ruthenium polypyridyl complexes have seen extensive use in solar energy applications. One of the most efficient dye-sensitized solar cells produced to date employs the dye-sensitizer N719, a ruthenium polypyridyl thiocyanate complex. Thiocyanate complexes are typically present as an inseparable mixture of N-bound and S-bound linkage isomers. Here we report the synthesis of a new complex, [Ru(terpy)(tbbpy)SCN][SbF(6)] (terpy = 2,2';6',2''-terpyridine, tbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine), as a mixture of N-bound and S-bound thiocyanate linkage isomers that can be separated based on their relative solubility in ethanol. Both isomers have been characterized spectroscopically and by X-ray crystallography. At elevated temperatures the isomers equilibrate, the product being significantly enriched in the more thermodynamically stable N-bound form. Density functional theory analysis supports our experimental observation that the N-bound isomer is thermodynamically preferred, and provides insight into the isomerization mechanism. PMID:22066656

  2. Evolutionary algorithm based structure search for hard ruthenium carbides

    NASA Astrophysics Data System (ADS)

    Harikrishnan, G.; Ajith, K. M.; Chandra, Sharat; Valsakumar, M. C.

    2015-12-01

    An exhaustive structure search employing evolutionary algorithm and density functional theory has been carried out for ruthenium carbides, for the three stoichiometries Ru1C1, Ru2C1 and Ru3C1, yielding five lowest energy structures. These include the structures from the two reported syntheses of ruthenium carbides. Their emergence in the present structure search in stoichiometries, unlike the previously reported ones, is plausible in the light of the high temperature required for their synthesis. The mechanical stability and ductile character of all these systems are established by their elastic constants, and the dynamical stability of three of them by the phonon data. Rhombohedral structure ≤ft(R\\bar{3}m\\right) is found to be energetically the most stable one in Ru1C1 stoichiometry and hexagonal structure ≤ft( P\\bar{6}m2\\right) , the most stable in Ru3C1 stoichiometry. RuC-Zinc blende system is a semiconductor with a band gap of 0.618 eV while the other two stable systems are metallic. Employing a semi-empirical model based on the bond strength, the hardness of RuC-Zinc blende is found to be a significantly large value of ~37 GPa while a fairly large value of ~21GPa is obtained for the RuC-Rhombohedral system. The positive formation energies of these systems show that high temperature and possibly high pressure are necessary for their synthesis.

  3. Platinum-ruthenium nanotubes and platinum-ruthenium coated copper nanowires as efficient catalysts for electro-oxidation of methanol

    DOE PAGESBeta

    Zheng, Jie; Cullen, David A.; Forest, Robert V.; Wittkopf, Jarrid A.; Zhuang, Zhongbin; Zheng, Whenchao; Chen, Jingguang G.; Yan, Yushan

    2015-01-15

    The sluggish kinetics of methanol oxidation reaction (MOR) is a major barrier to the commercialization of direct methanol fuel cells (DMFCs). In this study, we report a facile synthesis of platinum–ruthenium nanotubes (PtRuNTs) and platinum–ruthenium-coated copper nanowires (PtRu/CuNWs) by galvanic displacement reaction using copper nanowires as a template. The PtRu compositional effect on MOR is investigated; the optimum Pt/Ru bulk atomic ratio is about 4 and surface atomic ratio about 1 for both PtRuNTs and PtRu/CuNWs. Enhanced specific MOR activities are observed on both PtRuNTs and PtRu/CuNWs compared with the benchmark commercial carbon-supported PtRu catalyst (PtRu/C, Hispec 12100). Finally, x-raymore » photoelectron spectroscopy (XPS) reveals a larger extent of electron transfer from Ru to Pt on PtRu/CuNWs, which may lead to a modification of the d-band center of Pt and consequently a weaker bonding of CO (the poisoning intermediate) on Pt and a higher MOR activity on PtRu/CuNWs.« less

  4. Platinum-ruthenium nanotubes and platinum-ruthenium coated copper nanowires as efficient catalysts for electro-oxidation of methanol

    SciTech Connect

    Zheng, Jie; Cullen, David A.; Forest, Robert V.; Wittkopf, Jarrid A.; Zhuang, Zhongbin; Zheng, Whenchao; Chen, Jingguang G.; Yan, Yushan

    2015-01-15

    The sluggish kinetics of methanol oxidation reaction (MOR) is a major barrier to the commercialization of direct methanol fuel cells (DMFCs). In this study, we report a facile synthesis of platinum–ruthenium nanotubes (PtRuNTs) and platinum–ruthenium-coated copper nanowires (PtRu/CuNWs) by galvanic displacement reaction using copper nanowires as a template. The PtRu compositional effect on MOR is investigated; the optimum Pt/Ru bulk atomic ratio is about 4 and surface atomic ratio about 1 for both PtRuNTs and PtRu/CuNWs. Enhanced specific MOR activities are observed on both PtRuNTs and PtRu/CuNWs compared with the benchmark commercial carbon-supported PtRu catalyst (PtRu/C, Hispec 12100). Finally, x-ray photoelectron spectroscopy (XPS) reveals a larger extent of electron transfer from Ru to Pt on PtRu/CuNWs, which may lead to a modification of the d-band center of Pt and consequently a weaker bonding of CO (the poisoning intermediate) on Pt and a higher MOR activity on PtRu/CuNWs.

  5. Ruthenium or osmium complexes and their uses as catalysts for water oxidation

    DOEpatents

    Concepcion Corbea, Javier Jesus; Chen, Zuofeng; Jurss, Jonah Wesley; Templeton, Joseph L; Hoertz, Paul; Meyer, Thomas J

    2014-10-28

    The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

  6. Ruthenium or osmium complexes and their uses as catalysts for water oxidation

    DOEpatents

    Corbea, Javier Jesus Concepcion; Chen, Zuofeng; Jurss, Jonah Wesley; Templeton, Joseph L.; Hoertz, Paul; Meyer, Thomas J.

    2013-09-03

    The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

  7. CuAAC click reactions for the design of multifunctional luminescent ruthenium complexes.

    PubMed

    Zabarska, Natalia; Stumper, Anne; Rau, Sven

    2016-02-01

    CuAAC (Cu(i) catalyzed azide-alkyne cycloaddition) click chemistry has emerged as a versatile tool in the development of photoactive ruthenium complexes with multilateral potential applicability. In this contribution we discuss possible synthetic approaches towards CuAAC reactions with ruthenium(ii) polypyridine complexes and their differences with respect to possible applications. We focus on two main application possibilities of the click-coupled ruthenium assemblies. New results within the development of ruthenium based photosensitizers for the field of renewable energy supply, i.e. DSSCs (dye-sensitized solar cells) and artificial photocatalysis for the production of hydrogen, or for anticancer photodynamic therapeutic applications are reviewed. PMID:26758682

  8. Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for Lithium-O2 Batteries

    SciTech Connect

    Bhattacharya, Priyanka; Nasybulin, Eduard N.; Engelhard, Mark H.; Kovarik, Libor; Bowden, Mark E.; Li, Shari; Gaspar, Daniel J.; Xu, Wu; Zhang, Jiguang

    2014-12-01

    Dendrimer-encapsulated ruthenium nanoparticles (DEN-Ru) have been used as catalysts in lithium-O2 batteries for the first time. Results obtained from UV-vis spectroscopy, electron microscopy and X-ray photoelectron spectroscopy show that the nanoparticles synthesized by the dendrimer template method are ruthenium oxide instead of metallic ruthenium reported earlier by other groups. The DEN-Ru significantly improve the cycling stability of lithium (Li)-O2 batteries with carbon black electrodes and decrease the charging potential even at low catalyst loading. The monodispersity, porosity and large number of surface functionalities of the dendrimer template prevent the aggregation of the ruthenium nanoparticles making their entire surface area available for catalysis. The potential of using DEN-Ru as stand-alone cathode materials for Li-O2 batteries is also explored.

  9. Improving Grubbs' II type ruthenium catalysts by appropriately modifying the N-heterocyclic carbene ligand.

    PubMed

    Vieille-Petit, Ludovic; Luan, Xinjun; Gatti, Michele; Blumentritt, Sascha; Linden, Anthony; Clavier, Hervé; Nolan, Steven P; Dorta, Reto

    2009-07-01

    The introduction of N-heterocyclic carbene ligands that incorporate correctly substituted naphthyl side chains leads to increased activity and stability in second generation ruthenium metathesis catalysts. PMID:19557281

  10. Effects of ruthenium seed layer on the microstructure and spin dynamics of thin permalloy films

    NASA Astrophysics Data System (ADS)

    Jin, Lichuan; Zhang, Huaiwu; Tang, Xiaoli; Bai, Feiming; Zhong, Zhiyong

    2013-02-01

    The spin dynamics and microstructure properties of a sputtered 12 nm Ni81Fe19 thin film have been enhanced by the use of a ruthenium seed layer. Both the ferromagnetic resonance field and linewidth are enhanced dramatically as the thickness of ruthenium seed layer is increased. The surface anisotropy energy constant can also be largely tailored from 0.06 to 0.96 erg/cm-2 by changing the seed layer thickness. The changes to the dynamics magnetization properties are caused by both ruthenium seed layer induced changes in the Ni81Fe19 structure properties and surface topography properties. Roughness induced inhomogeneous linewidth broadening is also seen. The damping constant is highly tunable via the ruthenium thickness. This approach can be used to tailor both the structure and spin dynamic properties of thin Ni81Fe19 films over a wide range. And it may benefit the applications of spin dynamics and spin current based devices.

  11. Ruthenium nanocrystals as cathode catalysts for lithium-oxygen batteries with a superior performance

    PubMed Central

    Sun, Bing; Munroe, Paul; Wang, Guoxiu

    2013-01-01

    The key factor to improve the electrochemical performance of Li-O2 batteries is to find effective cathode catalysts to promote the oxygen reduction and oxygen evolution reactions. Herein, we report the synthesis of an effective cathode catalyst of ruthenium nanocrystals supported on carbon black substrate by a surfactant assisting method. The as-prepared ruthenium nanocrystals exhibited an excellent catalytic activity as cathodes in Li-O2 batteries with a high reversible capacity of about 9,800 mAh g−1, a low charge-discharge over-potential (about 0.37 V), and an outstanding cycle performance up to 150 cycles (with a curtaining capacity of 1,000 mAh g−1). The electrochemical testing shows that ruthenium nanocrystals can significantly reduce the charge potential comparing to carbon black catalysts, which demonstrated that ruthenium based nanomaterials could be effective cathode catalysts for high performance lithium- O2 batteries. PMID:23873349

  12. Ruthenium or osmium complexes and their uses as catalysts for water oxidation

    DOEpatents

    Corbea, Javier Jesus Concepcion; Chen, Zoufeng; Jurss, Jonah Wesley; Templeton, Joseph L.; Hoertz, Paul; Meyer, Thomas J.

    2016-06-07

    The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

  13. Platinum-ruthenium-palladium alloys for use as a fuel cell catalyst

    DOEpatents

    Gorer, Alexander

    2002-01-01

    A noble metal alloy composition for a fuel cell catalyst, a ternary alloy composition containing platinum, ruthenium and palladium. The alloy shows increased activity as compared to well-known catalysts.

  14. Ruthenium carbonyl catalyst supported on ceric oxide for preparation of olefins from synthesis gas

    DOEpatents

    Pierantozzi, Ronald

    1985-01-01

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  15. Preparation of olefins from synthesis gas using ruthenium supported on ceric oxide

    DOEpatents

    Pierantozzi, Ronald

    1985-01-01

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  16. Preparation and characterization of titanium dioxide nanotube array supported hydrated ruthenium oxide catalysts

    NASA Astrophysics Data System (ADS)

    Giang, Thi Phuong Ly; Tran, Thi Nhu Mai; Le, Xuan Tuan

    2012-03-01

    This work aimed at preparing and characterizing TiO2 nanotube supported hydrated ruthenium oxide catalysts. First of all, we succeeded in preparing TiO2 nanotube arrays by electrochemical anodization of titanium metal at 20 V for 8 h in a 1M H3PO4+0.5 wt% HF solution as evidenced from scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) results. The hydrated ruthenium oxide was then deposited onto TiO2 nanotubes by consecutive exchange of protons by Ru3+ ions, followed by formation of hydrated oxide during the alkali treatment. Further XPS measurements showed that the modified samples contain not only hydrated ruthenium oxide but also hydrated ruthenium species Ru(III)-OH.

  17. Ruthenium carbonyl catalyst supported on ceric oxide for preparation of olefins from synthesis gas

    DOEpatents

    Pierantozzi, R.

    1985-04-02

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  18. Preparation of olefins from synthesis gas using ruthenium supported on ceric oxide

    DOEpatents

    Pierantozzi, R.

    1985-04-09

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  19. Characterization of Palladium and Ruthenium after Reaction with Tetraphenylborate and Mercury

    SciTech Connect

    Duff, M.C.

    2001-09-11

    This report documents a second series of X-ray fine structure and chemical analyses to examine the form that Pd - and, to a lesser extent, ruthenium (Ru) - takes in simulated high-level slurries containing TPB salts.

  20. An electrochemical evaluation of ruthenium-based electrocatalysts for oxygen evolution

    NASA Astrophysics Data System (ADS)

    Valdez, Thomas I.

    A study of ruthenium oxide-based oxygen evolution catalysts for use in proton exchange membrane (PEM) electrolyzers was performed. In this work, oxygen evolution catalysts were fabricated via sol-gel, high energy ball milling, and thermal processing techniques. Thermal analysis techniques such as differential scanning calorimetry (DSC), differential thermal analysis (DTA), and thermal gravimetric analysis (TGA) were used to determine the optimum processing temperatures to be used for catalysts fabrication and annealing. The materials properties of the catalysts were studied with scanning electron microscopy, energy dispersive analysis (EDAX), X-ray diffraction, and X-ray photo-electron spectroscopy. Electrodes were fabricated from the oxygen evolution catalysts and tested in electrolysis and three-electrode cells. The catalysts fabricated via sol-gel techniques included a ruthenium oxide and an iridium-ruthenium oxide catalyst. Three families of the thermally processed catalysts were developed: iridium-ruthenium oxide, lead-ruthenium oxide, and tin ruthenium oxide. A lead oxide: ruthenium oxide catalyst was fabricated via high energy ball-milling to be used as a fabrication comparison to the thermally processed catalysts. The electrochemical evaluations for the oxygen evolution catalysts fabricated as electrolysis cells included current-step polarization and constant current electrolysis. The current step polarization experiments were used to determine the relative performance of the catalysts as well as to determine the kinetic parameters for the oxygen evolution reaction. The constant-current electrolysis experiments were used to estimate the degradation of the catalysts during operation. In these studies, it was determined that the thermal processing technique could produce stable and high performing catalysts. The thermally processed iridium ruthenium oxide catalysts with 9 to 12 mole percent iridium had the lowest overpotential for oxygen evolution of the

  1. Ruthenium on rutile catalyst, catalytic system, and method for aqueous phase hydrogenations

    DOEpatents

    Elliot, Douglas C.; Werpy, Todd A.; Wang, Yong; Frye, Jr., John G.

    2001-01-01

    An essentially nickel- and rhenium-free catalyst is described comprising ruthenium on a titania support where the titania is greater than 75% rutile. A catalytic system containing a nickel-free catalyst comprising ruthenium on a titania support where the titania is greater than 75% rutile, and a method using this catalyst in the hydrogenation of an organic compound in the aqueous phase is also described.

  2. Corrosion Investigations of Ruthenium in Potassium Periodate Solutions Relevant for Chemical Mechanical Polishing

    NASA Astrophysics Data System (ADS)

    Cheng, Jie; Wang, Tongqing; Pan, Jinshan; Lu, Xinchun

    2016-08-01

    Ruthenium is the most promising material for the barrier layer used for the sub 14 nm technology node in integrated circuits manufacturing. Potassium periodate (KIO4)-based slurry is used in the chemical mechanical planarization (CMP) process of the barrier layer. However, the electrochemical and corrosion properties of ruthenium have not been investigated in such slurry. In this paper, the electrochemical and corrosion behaviors of ruthenium in KIO4 solutions were investigated under static conditions but at different pH values by potentiodynamic polarization and electrochemical impedance spectroscopy measurements, combined with surface chemical analysis using auger electron spectroscopy. Moreover, to study wear enhanced corrosion during CMP, tribocorrosion experiments were carried out to monitor the current density changes during and after mechanical scratching. The results show that at pH 6, ruthenium forms a relatively thick and heterogeneous surface film composed of RuO2·2H2O/RuO3, showing a high corrosion resistance and it exhibits a quick repassivation after mechanical scratching. At pH 4, ruthenium shows a passivation behavior with formation of a uniform and conductive oxide like RuO2·2H2O. It should be noted that there is a possible formation of RuO4 toxic gas under this condition, which should be avoided in the actual production. However, at pH 11, ruthenium exhibits no considerable passivity and the corrosion proceeds uniformly.

  3. Corrosion Investigations of Ruthenium in Potassium Periodate Solutions Relevant for Chemical Mechanical Polishing

    NASA Astrophysics Data System (ADS)

    Cheng, Jie; Wang, Tongqing; Pan, Jinshan; Lu, Xinchun

    2016-05-01

    Ruthenium is the most promising material for the barrier layer used for the sub 14 nm technology node in integrated circuits manufacturing. Potassium periodate (KIO4)-based slurry is used in the chemical mechanical planarization (CMP) process of the barrier layer. However, the electrochemical and corrosion properties of ruthenium have not been investigated in such slurry. In this paper, the electrochemical and corrosion behaviors of ruthenium in KIO4 solutions were investigated under static conditions but at different pH values by potentiodynamic polarization and electrochemical impedance spectroscopy measurements, combined with surface chemical analysis using auger electron spectroscopy. Moreover, to study wear enhanced corrosion during CMP, tribocorrosion experiments were carried out to monitor the current density changes during and after mechanical scratching. The results show that at pH 6, ruthenium forms a relatively thick and heterogeneous surface film composed of RuO2·2H2O/RuO3, showing a high corrosion resistance and it exhibits a quick repassivation after mechanical scratching. At pH 4, ruthenium shows a passivation behavior with formation of a uniform and conductive oxide like RuO2·2H2O. It should be noted that there is a possible formation of RuO4 toxic gas under this condition, which should be avoided in the actual production. However, at pH 11, ruthenium exhibits no considerable passivity and the corrosion proceeds uniformly.

  4. Photochemical generation and kinetic studies of a putative porphyrin-ruthenium(V)-oxo species

    PubMed Central

    Zhang, Rui; Vanover, Eric; Luo, Weilong; Newcomb, Martin

    2014-01-01

    Photo-disproportionation of a bis-porphyrin-diruthenium(IV) μ-oxo dimer gave a porphyrin-ruthenium(III) species and a putative poprhyrin-ruthenium(V)-oxo species that can be detected and studied in real time via laser flash photolysis methods. As determined by its spectral and kinetic behavior, the same oxo transient was also formed by photolysis of a porphyrin-ruthenium(III) N-oxide adduct. Second-order rate constants for reactions with several substrates at 22 °C were determined; representative values of rate constants were kox = 6.6 × 103 M−1 s−1 for diphenylmethanol, kox = 2.5 × 103 M−1 s−1 for styrene, and kox = 1.8 × 103 M−1 s−1 for cyclohexene. The putative porphyrin-ruthenium(V)-oxo transient reacted 5–6 orders of magnitude faster than the corresponding trans-dioxoruthenium(VI)-oxo porphyrins, and the rate constants obtained in this work were similar to those of corrole-iron(V)-oxo derivative. The high reactivity for the photochemically generated ruthenium-oxo species in comparison to other poprhyrin-metal-oxo intermediates suggests it is a true ruthenium(V)-oxo species. PMID:24770388

  5. Carbon nanotubes dispersed in aqueous solution by ruthenium(ii) polypyridyl complexes.

    PubMed

    Huang, Kewei; Saha, Avishek; Dirian, Konstantin; Jiang, Chengmin; Chu, Pin-Lei E; Tour, James M; Guldi, Dirk M; Martí, Angel A

    2016-07-21

    Cationic ruthenium(ii) polypyridyl complexes with appended pyrene groups have been synthesized and used to disperse single-walled carbon nanotubes (SWCNT) in aqueous solutions. To this end, planar pyrene groups enable association by means of π-stacking onto carbon nanotubes and, in turn, the attachment of the cationic ruthenium complexes. Importantly, the ionic nature of the ruthenium complexes allows the formation of stable dispersions featuring individualized SWCNTs in water as confirmed in a number of spectroscopic and microscopic assays. In addition, steady-state photoluminescence spectroscopy was used to probe the excited state interactions between the ruthenium complexes and SWCNTs. These studies show that the photoluminescence of both, that is, of the ruthenium complexes and of SWCNTs, are quenched when they interact with each other. Pump-probe transient absorption experiments were performed to shed light onto the nature of the photoluminescence quenching, showing carbon nanotube-based bands with picosecond lifetimes, but no new bands which could be unambigously assigned to photoinduced charge transfer process. Thus, from the spectroscopic data, we conclude that quenching of the photoluminescence of the ruthenium complexes is due to energy transfer to proximal SWCNTs. PMID:27353007

  6. 99 Tips for Safe Schools.

    ERIC Educational Resources Information Center

    Kaufer, Steve

    This pamphlet highlights 99 tips for maintaining safe schools. Areas of interest include: alarm systems and control of access, vandalism, parent education, transportation, school design, personnel training, and graffiti. The majority of the pointers deal with maintaining and implementing various forms of electronic surveillance and strategies for…

  7. Museums and the Web '99.

    ERIC Educational Resources Information Center

    Bearman, David; Trant, Jennifer

    1999-01-01

    Discusses issues addressed at the Museums and the Web '99 conference (New Orleans, Louisiana, March 11-14, 1999). Highlights include how interaction with the virtual conditions views of the world; shared experiences of being online; virtual objects; new metaphors for seeking, finding and using information; evaluating creations; reconstructing; and…

  8. A selective, long-lived deep-red emissive ruthenium(II) polypyridine complexes for the detection of BSA

    NASA Astrophysics Data System (ADS)

    Babu, Eththilu; Muthu Mareeswaran, Paulpandian; Singaravadivel, Subramanian; Bhuvaneswari, Jayaraman; Rajagopal, Seenivasan

    2014-09-01

    A selective, label free luminescence sensor for bovine serum albumin (BSA) is investigated using ruthenium(II) complexes over the other proteins. Interaction between BSA and ruthenium(II) complexes has been studied using absorption, emission, excited state lifetime and circular dichroism (CD) spectral techniques. The luminescence intensity of ruthenium(II) complexes (I and II), has enhanced at 602 and 613 nm with a large hypsochromic shift of 18 and 5 nm respectively upon addition of BSA. The mode of binding of ruthenium(II) complexes with BSA has analyzed using computational docking studies.

  9. Size Effect of Ruthenium Nanoparticles in Catalytic Carbon Monoxide Oxidation

    SciTech Connect

    Joo, Sang Hoon; Park, Jeong Y.; Renzas, J. Russell; Butcher, Derek R.; Huang, Wenyu; Somorjai, Gabor A.

    2010-04-04

    Carbon monoxide oxidation over ruthenium catalysts has shown an unusual catalytic behavior. Here we report a particle size effect on CO oxidation over Ru nanoparticle (NP) catalysts. Uniform Ru NPs with a tunable particle size from 2 to 6 nm were synthesized by a polyol reduction of Ru(acac){sub 3} precursor in the presence of poly(vinylpyrrolidone) stabilizer. The measurement of catalytic activity of CO oxidation over two-dimensional Ru NPs arrays under oxidizing reaction conditions (40 Torr CO and 100 Torr O{sub 2}) showed an activity dependence on the Ru NP size. The CO oxidation activity increases with NP size, and the 6 nm Ru NP catalyst shows 8-fold higher activity than the 2 nm catalysts. The results gained from this study will provide the scientific basis for future design of Ru-based oxidation catalysts.

  10. Platinum adlayered ruthenium nanoparticles, method for preparing, and uses thereof

    DOEpatents

    Tong, YuYe; Du, Bingchen

    2015-08-11

    A superior, industrially scalable one-pot ethylene glycol-based wet chemistry method to prepare platinum-adlayered ruthenium nanoparticles has been developed that offers an exquisite control of the platinum packing density of the adlayers and effectively prevents sintering of the nanoparticles during the deposition process. The wet chemistry based method for the controlled deposition of submonolayer platinum is advantageous in terms of processing and maximizing the use of platinum and can, in principle, be scaled up straightforwardly to an industrial level. The reactivity of the Pt(31)-Ru sample was about 150% higher than that of the industrial benchmark PtRu (1:1) alloy sample but with 3.5 times less platinum loading. Using the Pt(31)-Ru nanoparticles would lower the electrode material cost compared to using the industrial benchmark alloy nanoparticles for direct methanol fuel cell applications.

  11. Exfoliated graphite-ruthenium oxide composite electrodes for electrochemical supercapacitors

    NASA Astrophysics Data System (ADS)

    Mitra, Sagar; Lokesh, K. S.; Sampath, S.

    The performance of exfoliated graphite (EG)-ruthenium oxide (RuO x) composites as binderless electrodes is evaluated for electrochemical capacitors (ECs). A composite of EG-RuO x is prepared by a modified sol-gel process. The material is characterized using X-ray diffraction and microscopy. Electrochemical capacitors with the composite electrodes in the presence of aqueous sulfuric acid (H 2SO 4) electrolyte are evaluated using voltammetry, impedance and charge-discharge studies. Cyclic voltammetry reveals very stable current-voltage behaviour up to several thousands of cycles, as well as high specific capacitances, e.g., a few hundreds of farads per gram for the composite that contains 16.5 wt.% RuO x.

  12. Ruthenium-Catalyzed Regioselective 1,4-Hydroboration of Pyridines.

    PubMed

    Kaithal, Akash; Chatterjee, Basujit; Gunanathan, Chidambaram

    2016-07-15

    Simple ruthenium precursor [Ru(p-cymene)Cl2]2 1 catalyzed regioselective 1,4-dearomatization of pyridine derivatives using pinacolborane is reported. Two catalytic intermediates, [Ru(p-cymene)Cl2Py] 2 and [Ru(p-cymene)Cl2(P(Cy)3)] 3, involved in this process are identified, independently synthesized, characterized, and further used directly as effective catalysts; two more catalytic intermediates [Ru(p-cymene)Cl2(Py)(P(Cy)3)] 4 and [Ru(p-cymene)(H)Cl(Py)(P(Cy)3)] 5 are identified in solution. Complex 5 is the active catalytic intermediate. An intramolecular selective 1,5-hydride transfer in 5 leading to the regioselective 1,4-hydroboration of pyridine compounds is proposed. PMID:27351256

  13. Spatial electrochromism in metallopolymeric films of ruthenium polypyridyl complexes

    SciTech Connect

    Leasure, R.M.; Ou, Wei; Moss, J.A.; Linton, R.W.

    1996-01-01

    Electropolymerized thin films of of poly[Ru(vbpy){sub 2}(py){sub 2}]{sup 2+} (vbpy is 4-vinyl-4{prime}-methyl-2,2{prime}-methyl-2,2{prime}-bipyridine; py is pyridine) were prepared. Photolysis of the films in the presence of chloride ion leads to photochemical substitution of Cl{sup -} for pyridine ligands, the structures of which were confirmed by small spot XPS. The absorption spectra and redox potentials of the ruthenium complexes were altered upon substitution of chloride for the pyridine ligands, suggesting the potential for using these materials to fabricate electrochromic film assemblies on optically transparent electrodes. The spectroelectrochemical response of the films was measured. 47 refs., 14 figs., 4 tabs.

  14. Similar Biological Activities of Two Isostructural Ruthenium and Osmium Complexes

    SciTech Connect

    Maksimoska,J.; Williams, D.; Atilla-Gokcumen, G.; Smalley, K.; Carroll, P.; Webster, R.; Filippakopoulos, P.; Knapp, S.; Herlyn, M.; Meggers, E.

    2008-01-01

    In this study, we probe and verify the concept of designing unreactive bioactive metal complexes, in which the metal possesses a purely structural function, by investigating the consequences of replacing ruthenium in a bioactive half-sandwich kinase inhibitor scaffold by its heavier congener osmium. The two isostructural complexes are compared with respect to their anticancer properties in 1205?Lu melanoma cells, activation of the Wnt signaling pathway, IC50 values against the protein kinases GSK-3? and Pim-1, and binding modes to the protein kinase Pim-1 by protein crystallography. It was found that the two congeners display almost indistinguishable biological activities, which can be explained by their nearly identical three-dimensional structures and their identical mode of action as protein kinase inhibitors. This is a unique example in which the replacement of a metal in an anticancer scaffold by its heavier homologue does not alter its biological activity.

  15. Hydrogen adsorption of ruthenium: Isosteres of solubility of adsorbed hydrogen

    SciTech Connect

    Zaginaichenko, S.Y.; Matysina, Z.A.; Schur, D.V.; Pishuk, V.K.

    1998-12-31

    The theoretical investigation of solubility isosteres of adsorbed hydrogen has been performed for free face (0001) of crystals with hexagonal close-packed lattice A3 of Mg type. The face free energy has been calculated and its dependence on temperature, pressure, hydrogen concentration and character of hydrogen atoms distribution over surface interstitial sites of different type has been defined. The equations of thermodynamic equilibrium and solubility of adsorbed hydrogen have been defined. The plots of isosteres in the region of phase transition from isotropic to anisotropic state have been constructed and it has been established that in anisotropic state the order in distribution of hydrogen atoms over interstitial sites of different type must become apparent. Comparison of the theoretical isosteres with experimental for ruthenium has been carried out, the isotropic-anisotropic state transition can stipulate a stepwise and break-like change in isosteres.

  16. Ruthenium-catalysed alkoxycarbonylation of alkenes with carbon dioxide.

    PubMed

    Wu, Lipeng; Liu, Qiang; Fleischer, Ivana; Jackstell, Ralf; Beller, Matthias

    2014-01-01

    Alkene carbonylations represent a major technology for the production of value-added bulk and fine chemicals. Nowadays, all industrial carbonylation processes make use of highly toxic and flammable carbon monoxide. Here we show the application of abundantly available carbon dioxide as C1 building block for the alkoxycarbonylations of industrially important olefins in the presence of a convenient and inexpensive ruthenium catalyst system. In our system, carbon dioxide works much better than the traditional combination of carbon monoxide and alcohols. The unprecedented in situ formation of carbon monoxide from carbon dioxide and alcohols permits an efficient synthesis of carboxylic acid esters, which can be used as detergents and polymer-building blocks. Notably, this transformation allows the catalytic formation of C-C bonds with carbon dioxide as C1 source and avoids the use of sensitive and/or expensive reducing agents (for example, Grignard reagents, diethylzinc or triethylaluminum). PMID:24518431

  17. Photophysical properties of monomeric and oligomeric ruthenium (II) porphyrins

    NASA Astrophysics Data System (ADS)

    Ikonen, Marjo; Guez, David; Marvaud, Valérie; Markovitsi, Dimitra

    1994-12-01

    The present Letter deals with three ruthenium(II) porphyrins: RuTBP(CO) (EtOH), RuTBP(pyz) 2 and [RuTBP(pyz)] n where TBP = tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl) porphyrin, EtOH = ethanol and pyz = pyrazine. Their photophysical properties are studied by steady-state and time-resolved absorption and emission spectroscopy. Each one of the examined compounds shows weak luminescence originating from a different electronic state: porphyrin triplet 3 (π,π ∗) for RuTBP (CO) (EtOH), equatorial 3LCT for RuTBP(pyz) 2 and axial 1MLCT for [RuTBP(pyz)] n.

  18. Gas-phase reactivity of ruthenium carbonyl cluster anions.

    PubMed

    Henderson, Matthew A; Kwok, Samantha; McIndoe, J Scott

    2009-04-01

    Partially-ligated anionic ruthenium carbonyl clusters react with alkenes, arenes, and alkanes in the gas phase; the products undergo extensive C-H activation and lose dihydrogen and carbon monoxide under collision-induced dissociation conditions. Triethylsilane and phenylsilane are also reactive towards the unsaturated clusters, and oxygen was shown to rapidly break down the cluster core by oxidative cleavage of the metal-metal bonds. These qualitative gas-phase reactivity studies were conducted using an easily-installed and inexpensive modification of a commercial electrospray ionization mass spectrometer. Interpretation of the large amounts of data generated in these studies is made relatively straightforward by employing energy-dependent electrospray ionization mass spectrometry (EDESI-MS). PMID:19185511

  19. Water-soluble ruthenium complexes bearing activity against protozoan parasites.

    PubMed

    Sarniguet, Cynthia; Toloza, Jeannette; Cipriani, Micaella; Lapier, Michel; Vieites, Marisol; Toledano-Magaña, Yanis; García-Ramos, Juan Carlos; Ruiz-Azuara, Lena; Moreno, Virtudes; Maya, Juan Diego; Azar, Claudio Olea; Gambino, Dinorah; Otero, Lucía

    2014-06-01

    Parasitic illnesses are major causes of human disease and misery worldwide. Among them, both amebiasis and Chagas disease, caused by the protozoan parasites, Entamoeba histolytica and Trypanosoma cruzi, are responsible for thousands of annual deaths. The lack of safe and effective chemotherapy and/or the appearance of current drug resistance make the development of novel pharmacological tools for their treatment relevant. In this sense, within the framework of the medicinal inorganic chemistry, metal-based drugs appear to be a good alternative to find a pharmacological answer to parasitic diseases. In this work, novel ruthenium complexes [RuCl2(HL)(HPTA)2]Cl2 with HL=bioactive 5-nitrofuryl containing thiosemicarbazones and PTA=1,3,5-triaza-7-phosphaadamantane have been synthesized and fully characterized. PTA was included as co-ligand in order to modulate complexes aqueous solubility. In fact, obtained complexes were water soluble. Their activity against T. cruzi and E. histolytica was evaluated in vitro. [RuCl2(HL4)(HPTA)2]Cl2 complex, with HL4=N-phenyl-5-nitrofuryl-thiosemicarbazone, was the most active compound against both parasites. In particular, it showed an excellent activity against E. histolytica (half maximal inhibitory concentration (IC50)=5.2 μM), even higher than that of the reference drug metronidazole. In addition, this complex turns out to be selective for E. histolytica (selectivity index (SI)>38). The potential mechanism of antiparasitic action of the obtained ruthenium complexes could involve oxidative stress for both parasites. Additionally, complexes could interact with DNA as second potential target by an intercalative-like mode. Obtained results could be considered a contribution in the search for metal compounds that could be active against multiple parasites. PMID:24740394

  20. Experimental chemotherapy in paracoccidioidomycosis using ruthenium NO donor.

    PubMed

    Pavanelli, Wander Rogério; da Silva, Jean Jerley Nogueira; Panis, Carolina; Cunha, Thiago Mattar; Costa, Ivete Conchon; de Menezes, Maria Claudia Noronha Dutra; Oliveira, Francisco José de Abreu; Lopes, Luiz Gonzaga de França; Cecchini, Rubens; Cunha, Fernando de Queiroz; Watanabe, Maria Angélica Ehara; Itano, Eiko Nakagawa

    2011-08-01

    Paracoccidioidomycosis (PCM) is a granulomatous disease caused by a dimorphic fungus, Paracoccidioides brasiliensis (Pb). To determine the influence of nitric oxide (NO) on this disease, we tested cis-[Ru(bpy)2(NO)SO3](PF6), ruthenium nitrosyl, which releases NO when activated by biological reducing agents, in BALB/c mice infected intravenously with Pb 18 isolate. In a previous study by our group, the fungicidal activity of ruthenium nitrosyl was evaluated in a mouse model of acute PCM, by measuring the immune cellular response (DTH), histopathological characteristics of the granulomatous lesions (and numbers), cytokines, and NO production. We found that cis-[Ru(bpy)2(NO)SO3](PF6)-treated mice were more resistant to infection, since they exhibited higher survival when compared with the control group. Furthermore, we observed a decreased influx of inflammatory cells in the lung and liver tissue of treated mice, possibly because of a minor reduction in fungal cell numbers. Moreover, an increased production of IL-10 and a decrease in TNF-α levels were detected in lung tissues of infected mice treated with cis-[Ru(bpy)2(NO)SO3](PF6). Immunohistochemistry showed that there was no difference in the number of VEGF- expressing cells. The animals treated with cis-[Ru(bpy)2(NO)SO3](PF6) showed high NO levels at 40 days after infection. These results show that NO is effectively involved in the mechanism that regulates the immune response in lung of Pb-infected mice. These data suggest that NO is a resistance factor during paracoccidioidomycosis by controlling fungal proliferation, influencing cytokine production, and consequently moderating the development of a strong inflammatory response. PMID:21437728

  1. Ammonia synthesis catalyzed by ruthenium supported on basic zeolites

    SciTech Connect

    Fishel, C.T.; Davis, R.J.; Garces, J.M.

    1996-09-15

    Ammonia synthesis was catalyzed by ruthenium metal clusters, promoted by alkali and alkaline earth elements, supported on zeolite X, magnesia, and pure silica MCM-41. At atmospheric total pressure and temperatures ranging from 623 to 723 K, the turnover frequencies of ammonia synthesis on Ru/KX varied significantly with Fu cluster size, demonstrating the known structure sensitivity of the reaction. Therefore, zeolite and magnesia catalysts were prepared with similar Ru cluster sizes, about 1 nm in diameter, in order to properly evaluate the effect of promoters. The same high degree of metal dispersion could not be obtained with Ru/MCM-41 catalysts. The turnover frequency for ammonia synthesis over Ru/CsX exceeded that over Ru/KX, consistent with the rank of promoter basicity. However, alkaline earth metals were more effective promoters than alkali metals for Ru supported on both zeolite X and MCM-41. Since alkaline earth metals are less basic; this promotional effect was unexpected. In addition, the turnover frequency for ammonia synthesis on Ru/BaX exceeded that of Ru/MgO, a nonzeolitic material. Pore volumes for Ru/BaX and Ru/KX measured by N{sub 2} adsorption were essentially identical, suggesting that pore blockage by ions within the zeolites does not account for the differences in reaction rates. The kinetics of ammonia synthesis over ruthenium differed considerably from what has been reported for industrial iron catalysts. Most significantly, the order of reaction in H{sub 2} was negative over Ru but is positive over Fe. A likely cause of this change in reaction order is that dissociated hydrogen atoms cover a greater fraction of the Ru clusters compared to Fe under reaction conditions. 49 refs., 8 figs., 10 tabs.

  2. Rapid determination of technetium-99 in large volume seawater samples using sequential injection extraction chromatographic separation and ICP-MS measurement.

    PubMed

    Shi, Keliang; Qiao, Jixin; Wu, Wangsuo; Roos, Per; Hou, Xiaolin

    2012-08-01

    An automated method was developed for rapid determination of (99)Tc in large volume seawater samples. The analytical procedure involves preconcentration of technetium with coprecipitation, online separation using extraction chromatography (two TEVA columns) implemented in a sequential injection setup, and measurement of (99)Tc by inductively coupled plasma mass spectrometry (ICP-MS). Chromatographic behaviors of technetium, molybdenum, and ruthenium were investigated, and the mechanism of adsorption and elution of TcO(4)(-) on a TEVA column using HNO(3) was explored. The results show that not only NO(3)(-) but also acidity (or concentration of H(+)) of the loading or eluting solution affect the adsorption and desorption of TcO(4)(-) on TEVA resin. Decontamination factors of more than 1 × 10(6) for ruthenium and 5 × 10(5) for molybdenum are achieved. Chemical yields of technetium in the overall procedure range from 60% to 75% depending on the sample volumes, and a detection limit of 7.5 mBq/m(3) (or 11.5 pg/m(3)) for 200 L of seawater was obtained. Compared with the conventional analytical procedure, the developed method significantly reduces analytical time. A batch of samples (n > 4) can be analyzed within 24 h. The method has been successfully applied for rapid and automated determination of low level (99)Tc in large volume seawater samples. The analytical results of seawater samples collected in Denmark show a good agreement with the values obtained using the conventional method. PMID:22783983

  3. STS-99 Crew News Conference

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Shuttle Crew (Mission Commander Kevin R. Kregel, Pilot Dominic L. Pudwill Gorie, Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri, and Gerhard P.J. Thiele) are shown in a live news conference presenting the mission objectives of STS-99. The main objective is to obtain the most complete high-resolution digital topographic database of Earth. This project is named the Shuttle Radar Topography Mission (SRTM).

  4. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility.

    PubMed

    Li, H F; Zhou, F Y; Li, L; Zheng, Y F

    2016-01-01

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co-Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10(-6) cm(3)·g(-1)-1.29 × 10(-6) cm(3)·g(-1) for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti-6Al-4V, ~3.5 × 10(-6) cm(3)·g(-1), CP Ti and Ti-6Al-7Nb, ~3.0 × 10(-6) cm(3)·g(-1)), and one-sixth that of Co-Cr alloys (Co-Cr-Mo, ~7.7 × 10(-6) cm(3)·g(-1)). Among the Zr-Ru alloy series, Zr-1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr-Ru alloy system as therapeutic devices under MRI diagnostics environments. PMID:27090955

  5. Development of a stable cobalt-ruthenium Fisher-Tropsch catalyst. Final report

    SciTech Connect

    Frame, R.R.; Gala, H.B.

    1995-02-01

    The reverse micelle catalyst preparation method has been used to prepare catalysts on four supports: magnesium oxide, carbon, alumina- titania and steamed Y zeolite. These catalysts were not as active as a reference catalyst prepared during previous contracts to Union Carbide Corp. This catalyst was supported on steamed Y zerolite support and was impregnated by a pore-filling method using a nonaqueous solvent. Additional catalysts were prepared via pore- filling impregnation of steamed Y zeolites. These catalysts had levels of cobalt two to three and a half times as high as the original Union Carbide catalyst. On a catalyst volume basis they were much more active than the previous catalyst; on an atom by atom basis the cobalt was about of the same activity, i.e., the high cobalt catalysts` cobalt atoms were not extensively covered over and deactivated by other cobalt atoms. The new, high activity, Y zerolite catalysts were not as stable as the earlier Union Carbide catalyst. However, stability enhancement of these catalysts should be possible, for instance, through adjustment of the quantity and/or type of trace metals present. A primary objective of this work was determination whether small amounts of ruthenium could enhance the activity of the cobalt F-T catalyst. The reverse micelle catalysts were not activated by ruthenium, indeed scanning transmission electronic microscopy (STEM) analysis provided some evidence that ruthenium was not present in the cobalt crystallites. Ruthenium did not seem to activate the high cobalt Y zeolite catalyst either, but additional experiments with Y zeolite-supported catalysts are required. Should ruthenium prove not to be an effective promoter under the simple catalyst activation procedure used in this work, more complex activation procedures have been reported which are claimed to enhance the cobalt/ruthenium interaction and result in activity promotion by ruthenium.

  6. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility

    NASA Astrophysics Data System (ADS)

    Li, H. F.; Zhou, F. Y.; Li, L.; Zheng, Y. F.

    2016-04-01

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co–Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10‑6 cm3·g‑1–1.29 × 10‑6 cm3·g‑1 for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti–6Al–4V, ~3.5 × 10‑6 cm3·g‑1, CP Ti and Ti–6Al–7Nb, ~3.0 × 10‑6 cm3·g‑1), and one-sixth that of Co–Cr alloys (Co–Cr–Mo, ~7.7 × 10‑6 cm3·g‑1). Among the Zr–Ru alloy series, Zr–1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr–Ru alloy system as therapeutic devices under MRI diagnostics environments.

  7. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility

    PubMed Central

    Li, H.F.; Zhou, F.Y.; Li, L.; Zheng, Y.F.

    2016-01-01

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co–Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10−6 cm3·g−1–1.29 × 10−6 cm3·g−1 for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti–6Al–4V, ~3.5 × 10−6 cm3·g−1, CP Ti and Ti–6Al–7Nb, ~3.0 × 10−6 cm3·g−1), and one-sixth that of Co–Cr alloys (Co–Cr–Mo, ~7.7 × 10−6 cm3·g−1). Among the Zr–Ru alloy series, Zr–1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr–Ru alloy system as therapeutic devices under MRI diagnostics environments. PMID:27090955

  8. New cytotoxic and water-soluble bis(2-phenylazopyridine)ruthenium(II) complexes.

    PubMed

    Hotze, Anna C G; Bacac, Marina; Velders, Aldrik H; Jansen, Bart A J; Kooijman, Huub; Spek, Anthony L; Haasnoot, Jaap G; Reedijk, Jan

    2003-04-24

    New water-soluble bis(2-phenylazopyridine)ruthenium(II) complexes, all derivatives of the highly cytotoxic alpha-[Ru(azpy)(2)Cl(2)] (alpha denoting the coordinating pairs Cl, N(py), and N(azo) as cis, trans, cis, respectively) have been developed. The compounds 1,1-cyclobutanedicarboxylatobis(2-phenylazopyridine)ruthenium(II), alpha-[Ru(azpy)(2)(cbdca-O,O')] (1), oxalatobis(2-phenylazopyridine)ruthenium(II), alpha-[Ru(azpy)(2)(ox)] (2), and malonatobis(2-phenylazopyridine)ruthenium(II), alpha-[Ru(azpy)(2)(mal)] (3), have been synthesized and fully characterized. X-ray analyses of 1 and 2 are reported, and compound 1 is the first example in which the cbdca ligand is coordinated to a ruthenium center. The cytotoxicity of this series of water-soluble bis(2-phenylazopyridine) complexes has been determined in A2780 human ovarian carcinoma and A2780cisR, the corresponding cisplatin-resistant cell line. For comparison reasons, the cytotoxicity of the complexes alpha-[Ru(azpy)(2)Cl(2)], alpha-[Ru(azpy)(2)(NO(3))(2)], beta-[Ru(azpy)(2)Cl(2)] (beta indicating the coordinating pairs Cl, N(py), and N(azo) as cis, cis, cis, respectively), and beta-[Ru(azpy)(2)(NO(3))(2)] have been determined in this cell line. All the bis(2-phenylazopyridine)ruthenium(II) compounds display a promising cytotoxicity in the A2780 cell line (IC(50) = 0.9-10 microM), with an activity comparable to that of cisplatin and even higher than the activity of carboplatin. Interestingly, the IC(50) values of this series of ruthenium compounds (except the beta isomeric compounds) are similar in the cisplatin-resistant A2780cisR cell line compared to the normal cell line A2780, suggesting that the activity of these compounds might not be influenced by the multifactorial resistance mechanism that affect platinum anticancer agents. PMID:12699392

  9. Preparation and Characterization of Polymer-Stabilized Ruthenium-Platinum and Ruthenium-Palladium Bimetallic Colloids and Their Catalytic Properties for Hydrogenation of o-Chloronitrobenzene.

    PubMed

    Liu; Yu; Liu; Zheng

    1999-06-15

    Colloidal dispersions of poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized ruthenium-platinum and ruthenium-palladium bimetallic colloids were prepared by NaBH4 reduction of the corresponding mixed-metal salts at room temperature and characterized by TEM, XPS, and XRD. The resulting bimetallic colloids were used as catalysts for the selective hydrogenation of o-chloronitrobenzene (o-CNB) in methanol at 303 K under 0.1 MPa of hydrogen. It was observed that the catalytic performance of PVP-stabilized ruthenium-platinum colloids (PVP-Ru/Pt) and ruthenium-palladium colloids (PVP-Ru/Pd) was dependent on their compositions and could be remarkably affected by some added metal cations. In the presence of cobalt ion, nearly 100% selectivity to o-chloroaniline (o-CAN) was achieved over PVP-Ru/Pt colloids at 100% conversion of o-CNB, with an activity two orders of magnitude higher than that of monometallic PVP-Ru colloid. Copyright 1999 Academic Press. PMID:10339363

  10. ONO-pincer ruthenium complex-bound norvaline for efficient catalytic oxidation of methoxybenzenes with hydrogen peroxide.

    PubMed

    Yoshida, Ryota; Isozaki, Katsuhiro; Yokoi, Tomoya; Yasuda, Nobuhiro; Sadakane, Koichiro; Iwamoto, Takahiro; Takaya, Hikaru; Nakamura, Masaharu

    2016-08-21

    The enhanced catalytic activity of ruthenium complex-bound norvaline Boc-l-[Ru]Nva-OMe 1, in which the ONO-pincer ruthenium complex Ru(pydc)(terpy) 2 is tethered to the α-side chain of norvaline, has been demonstrated for the oxidation of methoxybenzenes to p-benzoquinones with a wide scope of substrates and unique chemoselectivity. PMID:27314504

  11. A facile one-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica: Aqueous hydration of nitriles to amides

    EPA Science Inventory

    One-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium hydroxide immobilization; the hydration of nitriles occurs in high yield and excellent selectivity using this...

  12. Syntheses and Characterization of Ruthenium(II) Tetrakis(pyridine)complexes: An Advanced Coordination Chemistry Experiment or Mini-Project

    ERIC Educational Resources Information Center

    Coe, Benjamin J.

    2004-01-01

    An experiment for third-year undergraduate a student is designed which provides synthetic experience and qualitative interpretation of the spectroscopic properties of the ruthenium complexes. It involves the syntheses and characterization of several coordination complexes of ruthenium, the element found directly beneath iron in the middle of the…

  13. Time-resolved resonance raman spectra of polypyridyl complexes of ruthenium(II)

    SciTech Connect

    Kumar, C.V.; Barton, J.K.; Turro, N.J.; Gould, I.R.

    1987-05-06

    Time-resolved resonance Raman (TR/sup 3/) spectroscopy has recently evolved as a powerful tool for the investigation of the dynamics and structures of a variety of reactive intermediates, electronic excited states, biological systems, and enzyme-substrate complexes. In this communication, the authors report the TR/sup 3/ spectra of three ruthenium complexes of special importance because of three ruthenium complexes of special importance because of their binding ability to nucleic acids, because of their success as chiral probes that recognize the conformations and helicity of nucleic acids, and because of their potential to serve as models for the interaction of metal ions with nucleic acids. They report here the results of TR/sup 3/ and transient absorption experiments which demonstrate that the excited states of three Ru(II) complexes, tris(2,2'-bipyridyl)ruthenium(II) dichloride (I), tris(1,20-phenanthroline)-ruthenium(II) dichloride (II), and tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) dichloride (III), are indeed localized on the ligand.

  14. Band offsets of a ruthenium gate on ultrathin high-{kappa} oxide films on silicon

    SciTech Connect

    Rangan, Sylvie; Bersch, Eric; Bartynski, Robert Allen; Garfunkel, Eric; Vescovo, Elio

    2009-02-15

    Valence-band and conduction-band edges of ultrathin oxides (SiO{sub 2}, HfO{sub 2}, Hf{sub 0.7}Si{sub 0.3}O{sub 2}, and Al{sub 2}O{sub 3} grown on silicon) and their shifts upon sequential metallization with ruthenium have been measured using synchrotron-radiation-excited x-ray, ultraviolet, and inverse photoemissions. From these techniques, the offsets between the valence-band and conduction-band edges of the oxides, and the ruthenium metal gate Fermi edge have been directly measured. In addition the core levels of the oxides and the ruthenium have been characterized. Upon deposition, Ru remains metallic and no chemical alteration of the underlying oxide gates, or interfacial SiO{sub 2} in the case of the high-{kappa} thin films, can be detected. However a clear shift of the band edges is measured for all samples due to the creation of an interface dipole at the ruthenium-oxide interface. Using the energy gap, the electron affinity of the oxides, and the ruthenium work function that have been directly measured on these samples, the experimental band offsets are compared to those predicted by the induced gap states model.

  15. Transient Spectroscopic Characterization of the Genesis of a Ruthenium Complex Catalyst Supported on Zeolite Y

    SciTech Connect

    Ogino, Isao; Gates, Bruce C.

    2010-01-12

    A mononuclear ruthenium complex anchored to dealuminated zeolite HY, Ru(acac)(C{sub 2}H{sub 4}){sup 2+} (acac = acetylacetonate, C{sub 5}H{sub 7}O{sup 2}{sup -}), was characterized in flow reactors by transient infrared (IR) spectroscopy and Ru K edge X-ray absorption spectroscopy. The combined results show how the supported complex was converted into a form that catalyzes ethene conversion to butene. The formation of these species resulted from the removal of acac ligands from the ruthenium (as shown by IR and extended X-ray absorption fine structure (EXAFS) spectra) and the simultaneous decrease in the symmetry of the ruthenium complex, with the ruthenium remaining mononuclear and its oxidation state remaining essentially unchanged (as shown by EXAFS and X-ray absorption near-edge structure spectra). The removal of anionic acac ligands from the ruthenium was evidently compensated by the bonding of other anionic ligands, such as hydride from H2 in the feed stream, to form species suggested to be Ru(H)(C{sub 2}H{sub 4}){sub 2}{sup +}, which is coordinatively unsaturated and inferred to react with ethene, leading to the observed formation of butene in a catalytic process.

  16. Band Offsets of a Ruthenium Gate on Ultrathin High-k Oxide Films on Silicon

    SciTech Connect

    Rangan, S.; Bersch, W; Bartynski, R; Garfunkel, E; Vescovo, E

    2009-01-01

    Valence-band and conduction-band edges of ultrathin oxides and their shifts upon sequential metallization with ruthenium have been measured using synchrotron-radiation-excited x-ray, ultraviolet, and inverse photoemissions. From these techniques, the offsets between the valence-band and conduction-band edges of the oxides, and the ruthenium metal gate Fermi edge have been directly measured. In addition the core levels of the oxides and the ruthenium have been characterized. Upon deposition, Ru remains metallic and no chemical alteration of the underlying oxide gates, or interfacial SiO{sub 2} in the case of the high-? thin films, can be detected. However a clear shift of the band edges is measured for all samples due to the creation of an interface dipole at the ruthenium-oxide interface. Using the energy gap, the electron affinity of the oxides, and the ruthenium work function that have been directly measured on these samples, the experimental band offsets are compared to those predicted by the induced gap states model.

  17. Quantitative study of ruthenium cross-over in direct methanol fuel cells during early operation hours

    NASA Astrophysics Data System (ADS)

    Schoekel, A.; Melke, J.; Bruns, M.; Wippermann, K.; Kuppler, F.; Roth, C.

    2016-01-01

    In direct methanol fuel cells (DMFC), ruthenium cross-over is an important degradation phenomenon. The loss of ruthenium from the anode, its transport through the membrane and its deposition onto the cathode are detrimental to the fuel cell performance and limit the fuel cell's lifetime. Here we present a quantitative study on the fraction of ruthenium being transferred from the anode to the cathode during early operation hours (0-100 h) of a DMFC. Already during fabrication of the MEA ruthenium is transferred to the cathode. In our pristine MEAs about 0.024 wt% Ru could be found in the cathode catalyst. The cell potential during operation seems to have only a minor influence on the dissolution process. In contrast, the operation time appears to be much more important. Our data hint at two dissolution processes: a fast process dominating the first hours of operation and a slower process, which is responsible for the ongoing ruthenium transfer during the fuel cell lifetime. After 2 h held at open circuit conditions the Ru content of the cathode side was 10 times higher than in the pristine MEA. In contrast, the slower process increased that amount only by a factor of two over the course of another 100 h.

  18. Ligand Engineering for the Efficient Dye-Sensitized Solar Cells with Ruthenium Sensitizers and Cobalt Electrolytes.

    PubMed

    Aghazada, Sadig; Gao, Peng; Yella, Aswani; Marotta, Gabriele; Moehl, Thomas; Teuscher, Joël; Moser, Jacques-E; De Angelis, Filippo; Grätzel, Michael; Nazeeruddin, Mohammad Khaja

    2016-07-01

    Over the past 20 years, ruthenium(II)-based dyes have played a pivotal role in turning dye-sensitized solar cells (DSCs) into a mature technology for the third generation of photovoltaics. However, the classic I3(-)/I(-) redox couple limits the performance and application of this technique. Simply replacing the iodine-based redox couple by new types like cobalt(3+/2+) complexes was not successful because of the poor compatibility between the ruthenium(II) sensitizer and the cobalt redox species. To address this problem and achieve higher power conversion efficiencies (PCEs), we introduce here six new cyclometalated ruthenium(II)-based dyes developed through ligand engineering. We tested DSCs employing these ruthenium(II) complexes and achieved PCEs of up to 9.4% using cobalt(3+/2+)-based electrolytes, which is the record efficiency to date featuring a ruthenium-based dye. In view of the complicated liquid DSC system, the disagreement found between different characterizations enlightens us about the importance of the sensitizer loading on TiO2, which is a subtle but equally important factor in the electronic properties of the sensitizers. PMID:27322854

  19. Ruthenium nanoparticles in ionic liquids: structural and stability effects of polar solutes.

    PubMed

    Salas, Gorka; Podgoršek, Ajda; Campbell, Paul S; Santini, Catherine C; Pádua, Agílio A H; Costa Gomes, Margarida F; Philippot, Karine; Chaudret, Bruno; Turmine, Mireille

    2011-08-14

    Ionic liquids are a stabilizing medium for the in situ synthesis of ruthenium nanoparticles. Herein we show that the addition of molecular polar solutes to the ionic liquid, even in low concentrations, eliminates the role of the ionic liquid 3D structure in controlling the size of ruthenium nanoparticles, and can induce their aggregation. We have performed the synthesis of ruthenium nanoparticles by decomposition of [Ru(COD)(COT)] in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C(1)C(4)Im][NTf(2)], under H(2) in the presence of varying amounts of water or 1-octylamine. For water added during the synthesis of metallic nanoparticles, a decrease of the solubility in the ionic liquid was observed, showed by nanoparticles located at the interface between aqueous and ionic phases. When 1-octylamine is present during the synthesis, stable nanoparticles of a constant size are obtained. When 1-octylamine is added after the synthesis, aggregation of the ruthenium nanoparticles is observed. In order to explain these phenomena, we have explored the molecular interactions between the different species using (13)C-NMR and DOSY (Diffusional Order Spectroscopy) experiments, mixing calorimetry, surface tension measurements and molecular simulations. We conclude that the behaviour of the ruthenium nanoparticles in [C(1)C(4)Im][NTf(2)] in the presence of 1-octylamine depends on the interaction between the ligand and the nanoparticles in terms of the energetics but also of the structural arrangement of the amine at the nanoparticle's surface. PMID:21603700

  20. 32 CFR 99.3 - General definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of §§ 99.1 through 99.9 of this part: Criminal history record information: information collected by... history records information. Locality: any local government authority or agency or component...

  1. 50 CFR 665.99 - Area restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Area restrictions. 665.99 Section 665.99 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION... Ocean Survey Chart Number 83484....

  2. 50 CFR 665.99 - Area restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Area restrictions. 665.99 Section 665.99 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION... Ocean Survey Chart Number 83484....

  3. 50 CFR 665.99 - Area restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Area restrictions. 665.99 Section 665.99 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION... Ocean Survey Chart Number 83484....

  4. 50 CFR 665.99 - Area restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Area restrictions. 665.99 Section 665.99 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION... Ocean Survey Chart Number 83484....

  5. Radiation related complications after ruthenium plaque radiotherapy of uveal melanoma.

    PubMed Central

    Summanen, P; Immonen, I; Kivelä, T; Tommila, P; Heikkonen, J; Tarkkanen, A

    1996-01-01

    AIMS/BACKGROUND: To analyse radiation related complications and secondary enucleation after irradiation of malignant uveal melanoma with ruthenium-106 plaques. METHODS: A series of 100 consecutive eyes irradiated in 1981-91 was analysed using the life table method and the Cox proportional hazards model. The median apical and scleral tumour dose was 100 Gy (range 15-200 Gy) and 1000 Gy (range 200-1200 Gy), respectively. The median follow up time was 2.8 and 2.0 years (range 1 month to 10 years) for anterior and posterior segment complications, respectively. RESULTS: The 3 and 5 year probabilities of being without radiation cataract were 73% and 63%, without neovascular glaucoma 91% and 81%, without vitreous haemorrhage 83% and 74%, without radiation maculopathy 85% and 70%, and without radiation optic neuropathy 90% and 88%, respectively. The risk of radiation cataract was highest with large tumour size (T1 + T2 v T3, p = 0.0027; height < or = 5 v > 5 mm, p = 0.029; largest basal diameter (LBD) < or = 15 v > 15 mm, p < 0.0001) and location of anterior tumour margin anterior v posterior to the equator (p = 0.0003); the risk of neovascular glaucoma with large size (T1 + T2 v T3, p = 0.039; LBD < or = 15 mm v 15 mm, p = 0.021); and the risk of maculopathy and optic neuropathy with proximity of the posterior tumour margin to the fovea and the optic disc (< or = 1.5 v > 1.5 mm; p = 0.030 and p = 0.0004, respectively). In Cox's multivariate analysis the strongest risk indicator for radiation cataract (RR 1.5, 95% CI 1.4-1.6) and vitreous haemorrhage (RR 1.6, 95% CI 1.4-1.8) was the height of the tumour; for neovascular glaucoma the TNM class (RR 6.2, 95% CI 2.7-13.8); for radiation maculopathy location of posterior tumour margin within 2 mm from the fovea (RR 3.4, 95% CI 2.0-6.0); and for radiation optic neuropathy location of tumour margin within 1 DD of the optic disc (RR 6.1, 95% CI 3.0-12.4). The 3 and 5 year probabilities of avoiding enucleation were 92% and 85

  6. 22 CFR 99.3 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false 99.3 Section 99.3 Foreign Relations DEPARTMENT OF STATE LEGAL AND RELATED SERVICES REPORTING ON CONVENTION AND NON-CONVENTION ADOPTIONS OF EMIGRATING CHILDREN § 99.3...

  7. 29 CFR 99.230 - Audit costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... principles circulars, the Federal Acquisition Regulation (FAR)(48 CFR parts 30 and 31), or other applicable... 29 Labor 1 2010-07-01 2010-07-01 true Audit costs. 99.230 Section 99.230 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.230...

  8. 29 CFR 99.505 - Audit reporting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Audit reporting. 99.505 Section 99.505 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditors § 99.505 Audit... the audit was conducted in accordance with this part and include the following: (a) An opinion...

  9. 25 CFR 700.99 - Salvage value.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Salvage value. 700.99 Section 700.99 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.99 Salvage value. Salvage value means the probable sale price of...

  10. 25 CFR 700.99 - Salvage value.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Salvage value. 700.99 Section 700.99 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.99 Salvage value. Salvage value means the probable sale price of...

  11. 25 CFR 700.99 - Salvage value.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Salvage value. 700.99 Section 700.99 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.99 Salvage value. Salvage value means the probable sale price of...

  12. 25 CFR 700.99 - Salvage value.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Salvage value. 700.99 Section 700.99 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.99 Salvage value. Salvage value means the probable sale price of...

  13. 25 CFR 700.99 - Salvage value.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Salvage value. 700.99 Section 700.99 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.99 Salvage value. Salvage value means the probable sale price of...

  14. 29 CFR 99.405 - Management decision.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 1 2012-07-01 2012-07-01 false Management decision. 99.405 Section 99.405 Labor Office of... Agencies and Pass-through Entities § 99.405 Management decision. (a) General. The management decision shall... the management decision, the Federal agency or pass-through entity may request additional...

  15. 29 CFR 99.405 - Management decision.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false Management decision. 99.405 Section 99.405 Labor Office of... Agencies and Pass-through Entities § 99.405 Management decision. (a) General. The management decision shall... the management decision, the Federal agency or pass-through entity may request additional...

  16. 29 CFR 99.405 - Management decision.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Management decision. 99.405 Section 99.405 Labor Office of... Agencies and Pass-through Entities § 99.405 Management decision. (a) General. The management decision shall... the management decision, the Federal agency or pass-through entity may request additional...

  17. 29 CFR 99.405 - Management decision.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true Management decision. 99.405 Section 99.405 Labor Office of... Agencies and Pass-through Entities § 99.405 Management decision. (a) General. The management decision shall... the management decision, the Federal agency or pass-through entity may request additional...

  18. 29 CFR 99.405 - Management decision.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false Management decision. 99.405 Section 99.405 Labor Office of... Agencies and Pass-through Entities § 99.405 Management decision. (a) General. The management decision shall... the management decision, the Federal agency or pass-through entity may request additional...

  19. 45 CFR 99.23 - Discovery.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Discovery. 99.23 Section 99.23 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.23 Discovery. The Department, the Lead Agency, and any individuals or groups recognized as parties shall have the right to conduct discovery (including depositions)...

  20. 45 CFR 99.23 - Discovery.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Discovery. 99.23 Section 99.23 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.23 Discovery. The Department, the Lead Agency, and any individuals or groups recognized as parties shall have the right to conduct discovery (including depositions)...

  1. 45 CFR 99.23 - Discovery.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Discovery. 99.23 Section 99.23 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.23 Discovery. The Department, the Lead Agency, and any individuals or groups recognized as parties shall have the right to conduct discovery (including depositions)...

  2. 45 CFR 99.23 - Discovery.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Discovery. 99.23 Section 99.23 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.23 Discovery. The Department, the Lead Agency, and any individuals or groups recognized as parties shall have the right to conduct discovery (including depositions)...

  3. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education....

  4. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education....

  5. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education....

  6. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education....

  7. 45 CFR 99.23 - Discovery.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Discovery. 99.23 Section 99.23 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.23 Discovery. The Department, the Lead Agency, and any individuals or groups recognized as parties shall have the right to conduct discovery (including depositions)...

  8. 14 CFR 99.47 - Guam ADIZ.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Guam ADIZ. 99.47 Section 99.47 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99.47 Guam ADIZ. (a) Inner boundary. From...

  9. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99.49 Hawaii ADIZ. (a) Outer boundary....

  10. 29 CFR 99.400 - Responsibilities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 1 2012-07-01 2012-07-01 false Responsibilities. 99.400 Section 99.400 Labor Office of the... Pass-through Entities § 99.400 Responsibilities. (a) Cognizant agency for audit responsibilities... programs of more than one agency. (8) Coordinate the audit work and reporting responsibilities...

  11. 29 CFR 99.400 - Responsibilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false Responsibilities. 99.400 Section 99.400 Labor Office of the... Pass-through Entities § 99.400 Responsibilities. (a) Cognizant agency for audit responsibilities... programs of more than one agency. (8) Coordinate the audit work and reporting responsibilities...

  12. 29 CFR 99.510 - Audit findings.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true Audit findings. 99.510 Section 99.510 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditors § 99.510 Audit findings. (a) Audit findings reported. The auditor shall report the following as audit findings in...

  13. 29 CFR 99.510 - Audit findings.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false Audit findings. 99.510 Section 99.510 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditors § 99.510 Audit findings. (a) Audit findings reported. The auditor shall report the following as audit findings in...

  14. 29 CFR 99.510 - Audit findings.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false Audit findings. 99.510 Section 99.510 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditors § 99.510 Audit findings. (a) Audit findings reported. The auditor shall report the following as audit findings in...

  15. 29 CFR 99.510 - Audit findings.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 1 2012-07-01 2012-07-01 false Audit findings. 99.510 Section 99.510 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditors § 99.510 Audit findings. (a) Audit findings reported. The auditor shall report the following as audit findings in...

  16. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education....

  17. 45 CFR 99.25 - Evidence.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Evidence. 99.25 Section 99.25 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.25 Evidence. (a) Testimony. Testimony shall be given orally under... conference or otherwise prior to the hearing if the presiding officer so requires. (c) Rules of...

  18. 32 CFR 552.99 - Applicability.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 3 2012-07-01 2009-07-01 true Applicability. 552.99 Section 552.99 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY MILITARY RESERVATIONS AND NATIONAL CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Firearms and Weapons § 552.99 Applicability. (a)...

  19. 29 CFR 99.230 - Audit costs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... principles circulars, the Federal Acquisition Regulation (FAR)(48 CFR parts 30 and 31), or other applicable... 29 Labor 1 2013-07-01 2013-07-01 false Audit costs. 99.230 Section 99.230 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.230...

  20. 29 CFR 99.230 - Audit costs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... principles circulars, the Federal Acquisition Regulation (FAR)(48 CFR parts 30 and 31), or other applicable... 29 Labor 1 2011-07-01 2011-07-01 false Audit costs. 99.230 Section 99.230 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.230...

  1. 29 CFR 99.230 - Audit costs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... principles circulars, the Federal Acquisition Regulation (FAR)(48 CFR parts 30 and 31), or other applicable... 29 Labor 1 2014-07-01 2013-07-01 true Audit costs. 99.230 Section 99.230 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.230...

  2. 29 CFR 99.230 - Audit costs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... principles circulars, the Federal Acquisition Regulation (FAR)(48 CFR parts 30 and 31), or other applicable... 29 Labor 1 2012-07-01 2012-07-01 false Audit costs. 99.230 Section 99.230 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.230...

  3. 45 CFR 99.31 - Posthearing briefs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Posthearing briefs. 99.31 Section 99.31 Public... CHILD CARE AND DEVELOPMENT FUND Posthearing Procedures, Decisions § 99.31 Posthearing briefs. The presiding officer shall fix the time for filing posthearing briefs, which may contain proposed findings...

  4. 45 CFR 99.31 - Posthearing briefs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Posthearing briefs. 99.31 Section 99.31 Public... CHILD CARE AND DEVELOPMENT FUND Posthearing Procedures, Decisions § 99.31 Posthearing briefs. The presiding officer shall fix the time for filing posthearing briefs, which may contain proposed findings...

  5. 29 CFR 99.400 - Responsibilities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false Responsibilities. 99.400 Section 99.400 Labor Office of the... Pass-through Entities § 99.400 Responsibilities. (a) Cognizant agency for audit responsibilities... programs of more than one agency. (8) Coordinate the audit work and reporting responsibilities...

  6. 27 CFR 21.99 - Brucine alkaloid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Brucine alkaloid. 21.99 Section 21.99 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.99 Brucine alkaloid. (a) Identification...

  7. 29 CFR 99.320 - Report submission.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 1 2012-07-01 2012-07-01 false Report submission. 99.320 Section 99.320 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditees § 99.320 Report submission. (a) General. The audit shall be completed and the data collection form described in paragraph (b) of this section...

  8. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  9. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal...

  10. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal...

  11. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal...

  12. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal...

  13. 42 CFR 9.9 - Facility staffing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Facility staffing. 9.9 Section 9.9 Public Health... CHIMPANZEES HELD IN THE FEDERALLY SUPPORTED SANCTUARY SYSTEM § 9.9 Facility staffing. How many personnel are... operation of the sanctuary. Sufficiently trained staff also must be available to maintain...

  14. Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

    PubMed

    Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

    2015-01-01

    This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo. PMID:25537991

  15. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  16. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  17. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  18. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  19. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  20. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  1. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  2. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  3. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the...

  4. 29 CFR 99.400 - Responsibilities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true Responsibilities. 99.400 Section 99.400 Labor Office of the... Pass-through Entities § 99.400 Responsibilities. (a) Cognizant agency for audit responsibilities... programs of more than one agency. (8) Coordinate the audit work and reporting responsibilities...

  5. 46 CFR 111.99-1 - Applicability.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Applicability. 111.99-1 Section 111.99-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Fire Door Holding and Release Systems § 111.99-1 Applicability. This subpart applies to fire...

  6. 46 CFR 111.99-1 - Applicability.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Applicability. 111.99-1 Section 111.99-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Fire Door Holding and Release Systems § 111.99-1 Applicability. This subpart applies to fire...

  7. 46 CFR 111.99-1 - Applicability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Applicability. 111.99-1 Section 111.99-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Fire Door Holding and Release Systems § 111.99-1 Applicability. This subpart applies to fire...

  8. 46 CFR 111.99-1 - Applicability.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Applicability. 111.99-1 Section 111.99-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Fire Door Holding and Release Systems § 111.99-1 Applicability. This subpart applies to fire...

  9. 46 CFR 111.99-1 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Applicability. 111.99-1 Section 111.99-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Fire Door Holding and Release Systems § 111.99-1 Applicability. This subpart applies to fire...

  10. 47 CFR 22.99 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Definitions. 22.99 Section 22.99 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Scope and Authority § 22.99 Definitions. Terms used in this part have the following meanings: Air-Ground Radiotelephone Service. A radio service in...