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Sample records for ammines

  1. Surface adsorption in strontium chloride ammines

    DEFF Research Database (Denmark)

    Ammitzbøll, Andreas L.; Lysgaard, Steen; Klukowska, Agata;

    2013-01-01

    An adsorbed state and its implications on the ab- and desorption kinetics of ammonia in strontium chloride ammine is identified using a combination of ammonia absorption measurements, thermogravimetric analysis, and density functional theory calculations. During thermogravimetric analysis, ammoni...

  2. Metal ammine complexes for hydrogen storage

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Sørensen, Rasmus Zink; Johannessen, Tue;

    2005-01-01

    The hopes of using hydrogen as an energy carrier are severely dampened by the fact that there is still no safe, high-density method available for storing hydrogen. We investigate the possibility of using metal ammine complexes as a solid form of hydrogen storage. Using Mg(NH3)(6)Cl-2 as the example...

  3. Computational screening of mixed metal halide ammines

    DEFF Research Database (Denmark)

    Jensen, Peter Bjerre; Lysgaard, Steen; Quaade, Ulrich;

    . In this project we are searching for improved mixed materials with optimal desorption temperatures and kinetics, optimally releasing all ammonia in one step. We apply Density Functional Theory, DFT, calculations on mixed compounds selected by a Genetic Algorithm (GA), relying on biological principles of natural......Metal halide ammines, e.g. Mg(NH3)6Cl2 and Sr(NH3)8Cl2, can reversibly store ammonia, with high volumetric hydrogen storage capacities. The storage in the halide ammines is very safe, and the salts are therefore highly relevant as a carbon-free energy carrier in future transportation infrastructure...... selection. The GA is evolving from an initial (random) population and selecting those with highest fitness, a function based on e.g. stability, release temperature and storage capacity. The search space includes all alkaline, alkaline earth, 3d and 4d metals and the four lightest halides. In total...

  4. Computational Screening of Mixed Metal Halide Ammines

    DEFF Research Database (Denmark)

    Jensen, Peter Bjerre; Lysgaard, Steen; Quaade, Ulrich;

    selected by a Genetic Algorithm (GA), relying on biological principles of natural selection. The GA is evolving from an initial (random) population and selecting those with highest fitness, e.g. stability, release temperature and storage capacity. The search space includes all alkaline, alkaline earth, 3d......Metal halide ammines, e.g. Mg(NH3)6Cl2 and Sr(NH3)8Cl2, can reversibly store ammonia, with high volumetric hydrogen storage capacities. In this project we are searching for improved mixed materials with optimal desorption temperature and kinetics. We apply DFT calculations on mixed compounds...

  5. A study on synthetic method and material characteristics of magnesium ammine chloride as ammonia transport materials for solid SCR

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jong Kook; Yoon, Cheon Seog [Dept. of Mechanical Engineering, Hannam University, Daejeon (Korea, Republic of); Kim, Hong Suk [Engine Research Center, Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2015-11-15

    Among various ammonium salts and metal ammine chlorides used as solid materials for the sources of ammonia with solid SCR for lean NOx reduction, magnesium ammine chloride was taken up for study in this paper because of its ease of handling and safety. Lab-scale synthetic method of magnesium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%). To understand material characteristics for lab-made magnesium ammine chloride, DA, IC, FT-IR, XRD and SDT analyses were performed using the published data available in literature. From the analytical results, the water content in the lab-made magnesium ammine chloride can be determined. A new test procedure for water removal was proposed, by which the adsorption rate of lab-made sample was found to be approximately 100%.

  6. Thermochromic transitions of some tetrachlorocuprates of protonated ammines determined by differential scanning calorimetry

    Science.gov (United States)

    Fernández, F.; Fernández, V.; Gutiérrez-Rios, M. a.T.; Sánchez, C.

    1990-11-01

    The enthalpies of the thermochromic phase transitions of the tetrachlorocuprates (II) of a group of protonated ammines (n-propyl (I), iso-propyl (II), n-butyl (III), iso-butyl (IV), octyl (V), lauryl-ammine (VI), pyridine (VII) and piperidine (VIII)) have been determined by DSC. The transition temperatures correlate with the colour change shown by the samples. It is concluded that these transitions are associated with a modification of the CuCl 42- structure to a more square-planar one in some of the compounds (I, II, III, IV, V, VI) and with a deformation to a more tetrahedral one in the other compounds (VII and VIII).

  7. Indirect, reversible high-density hydrogen storage in compact metal ammine salts

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Zink; Hummelshøj, Jens Strabo; Klerke, Asbjørn;

    2008-01-01

    structures develop, which facilitates desorption from the interior of large, compact tablets. Density functional theory calculations reproduce trends in desorption enthalpies for the systems studied, and a mechanism in which individual chains of the ammines are released from the surface of the crystal...

  8. Designing mixed metal halide ammines for ammonia storage using density functional theory and genetic algorithms

    DEFF Research Database (Denmark)

    Jensen, Peter Bjerre; Lysgaard, Steen; Quaade, Ulrich J.;

    2014-01-01

    to be supplied, making the total efficiency lower. Here, we apply density functional theory (DFT) calculations to predict new mixed metal halide ammines with improved storage capacities and the ability to release the stored ammonia in one step, at temperatures suitable for system integration with polymer...... capacities. The size of the search space and the chosen fitness function make it possible to verify that the found candidates are the best possible candidates in the search space, proving that the GA implementation is ideal for this kind of computational materials design, requiring calculations on less than...

  9. Designing mixed metal halide ammines for ammonia storage using density functional theory and genetic algorithms.

    Science.gov (United States)

    Jensen, Peter Bjerre; Lysgaard, Steen; Quaade, Ulrich J; Vegge, Tejs

    2014-09-28

    Metal halide ammines have great potential as a future, high-density energy carrier in vehicles. So far known materials, e.g. Mg(NH3)6Cl2 and Sr(NH3)8Cl2, are not suitable for automotive, fuel cell applications, because the release of ammonia is a multi-step reaction, requiring too much heat to be supplied, making the total efficiency lower. Here, we apply density functional theory (DFT) calculations to predict new mixed metal halide ammines with improved storage capacities and the ability to release the stored ammonia in one step, at temperatures suitable for system integration with polymer electrolyte membrane fuel cells (PEMFC). We use genetic algorithms (GAs) to search for materials containing up to three different metals (alkaline-earth, 3d and 4d) and two different halides (Cl, Br and I) - almost 27,000 combinations, and have identified novel mixtures, with significantly improved storage capacities. The size of the search space and the chosen fitness function make it possible to verify that the found candidates are the best possible candidates in the search space, proving that the GA implementation is ideal for this kind of computational materials design, requiring calculations on less than two percent of the candidates to identify the global optimum. PMID:25115581

  10. Solid-phase synthesis of protected peptides using new cobalt(III) ammine linkers.

    Science.gov (United States)

    Arbo, B E; Isied, S S

    1993-08-01

    Cobalt(III) ammine complexes of the type cis-[CoL4(4-AMB)O-AA-Boc](CF3SO3)2, where L4 = bisethylenediamine (en)2 or tetraammine (NH3)4, and 4-AMB = 4-(aminomethyl)benzoic acid, have been synthesized and used as linkers to polystyrene resins for solid-phase synthesis of protected peptides. Boc/t-Bu-protected [Leu5]enkephalin was assembled on the two different Co(III) resins, and then cleaved from the resins by reduction of the Co(III) center in 93-96% yield. HPLC-purified protected [Leu5]enkephalin was obtained in 67-69% overall yield and characterized by amino acid analysis and 1H NMR. Stepwise synthesis on the Co(en)2-resin was also used in the assembly of Boc-Asp(OcHex)-Arg(Mts)-Gly-Asp(OcHex)-Ala-Pro-Lys(2Cl-Z)-Gl y-OH, a sequence from collagen alpha 1 Type 1. The protected peptide was cleaved from the Co(III) resin in 74% yield, and the HPLC-purified nonapeptide was characterized by amino acid analysis, 1H NMR and liquid secondary-ion mass spectrometry (LSIMS). New routes are described for the synthesis of isomerically pure Co(III) anchor complexes. The Co(III) resins were found to be compatible with both the tert-butyloxycarbonyl (Boc) and the 9-fluorenylmethoxycarbonyl (Fmoc) N alpha-protecting group strategies used in solid-phase peptide synthesis.

  11. Improved Automotive NO (x) Aftertreatment System: Metal Ammine Complexes as NH3 Source for SCR Using Fe-Containing Zeolite Catalysts

    DEFF Research Database (Denmark)

    Johannessen, Tue; Schmidt, Henning; Frey, Anne Mette;

    2009-01-01

    Ammonia storage is a challenge in the selective catalytic reduction of NO (x) in vehicles. We propose a new system, based on metal ammines as the ammonia source. In combination with iron containing zeolites as the SCR catalyst it should be possible to obtain a low temperature system for NO (x...

  12. Preclinical toxicology and tissue platinum distribution of novel oral antitumour platinum complexes: ammine/amine platinum(IV) dicarboxylates.

    Science.gov (United States)

    McKeage, M J; Morgan, S E; Boxall, F E; Murrer, B A; Hard, G C; Harrap, K R

    1994-01-01

    The preclinical toxicology and tissue platinum distribution of a series of six orally given antitumour platinum complexes [ammine/amine platinum(IV) dicarboxylates] with structural variations of their alicyclic amine (c-C5, c-C6 or c-C7), axial dicarboxylate (CH3, C3H7 or NHC2H5) or leaving substituents (Cl2 or OCOOCO) was studied in the mouse. Platinum tissue levels measured at 48 h after a single oral dose at 0.5 of the MTD were highest in the liver (6.0-19 micrograms/g) and second highest in the kidney (2.8-12 micrograms/g), and these levels were up to 5 times higher than those reported with equi-toxic doses of i.v. cisplatin and i.v. carboplatin. Platinum levels in the lung, heart, spleen, skin, skeletal muscle and brain were all plasma ALT activity were recorded with single oral doses of JM225 and JM256 at the MTD. Accumulation of platinum in the liver with repeated oral dosing weekly for 4 consecutive weeks at 0.5 of the MTD occurred with JM269 (3.3-fold increase, P plasma ALT activity (44 +/- 33 IU/l) was recorded with repeated oral doses of JM269. JM216 was selected from this series of analogues for further study on the basis of the elevated plasma ALT activity (JM225, JM256 and JM269), liver platinum accumulation (JM269 and JM225), poor activity against human ovarian carcinoma xenografts (JM291) or severe emetogenesis (JM221) of other examples. Following a single oral dose of JM216 at the MTD, transient reductions in the WBC (nadir, 1.6 x 10(9)/l, 2 days, 74% reduction), platelet count (nadir, 613 x 10(9)/l, 10 days, 33% reduction) and bone marrow cellularity (nadir, 0.5 x 10(7) nucleated cells/femur, 4 days, 75% reduction) were found, and these had recovered by 21 days after treatment. Jejunal mucosal disaccharidase activity following single MTDs indicated that small-intestinal mucosal damage was less severe for oral JM216 (nadir maltase activity, 68% +/- 16% of control, NS) than for i.v. cisplatin (nadir maltase activity).(ABSTRACT TRUNCATED AT 400 WORDS

  13. Tetra-ammine-2κ(4) C-μ-cyanido-1:2κ(2) C:N-tricyanido-1κ(3) C-copper(II)palladium(II).

    Science.gov (United States)

    Suchá, Veronika; Kuchár, Juraj; Harms, Klaus

    2013-05-01

    The title compound, [Cu(NH3)4-(μ2-NC)-Pd(CN)3], is a binuclear copper(II)palladium(II) complex, in which the Cu(II) coordination is defined by four ammine ligands and one bridging cyanide ligand. The Cu-N bond lengths in the base of the resulting CuN5 pyramid are in the range 2.016 (3)-2.024 (3) Å and the apical Cu-N( C) distance is 2.385 (4) Å. Based on the τ parameter, the shape of the coordination polyhedron is tetra-gonal-pyramidal (τ = 0). All atoms of the square-planar tetracyanidopalladate(II) moiety and the Cu(II) ion are located on a mirror plane. The electroneutral mol-ecules inter-act by N-H⋯N hydrogen bonds, resulting in the formation of a three-dimensional network. PMID:23723754

  14. FeF3@Thin Nickel Ammine Nitrate Matrix: Smart Configurations and Applications as Superior Cathodes for Li-Ion Batteries.

    Science.gov (United States)

    Jiang, Jian; Li, Linpo; Xu, Maowen; Zhu, Jianhui; Li, Chang Ming

    2016-06-29

    Iron fluorides (FeFx) for Li-ion battery cathodes are still in the stage of intensive research due to their low delivery capacity and limited lifetime. One critical reason for cathode degradation is the severe aggregation of FeFx nanocrystals upon long-term cycling. To maximize the capacity and cyclability of these cathodes, we propose herein a novel and applicable method using a thin-layered nickel ammine nitrate (NAN) matrix as a feasible encapsulation material to disperse the FeF3 nanoparticles. Such core-shell hybrids with smart configurations are constructed via a green, scalable, in situ encapsulation approach. The outer thin-film NAN matrix with prominent electrochemical stability can keep the FeF3 nanoactives encapsulated throughout the cyclic testing, protecting them from adverse aggregation into bulk crystals and thus leading to drastic improvements of electrode behaviors (e.g., high electrode capacity up to ∼423 mA h g(-1), greatly prolonged cyclic period, and promoted rate capabilities). This present work may set up a new and general platform to develop intriguing core-shell hybrid cathodes for Li-ion batteries, not only for FeFx but also for a wide spectrum of other cathode materials. PMID:27269361

  15. Organometallic cis-Dichlorido Ruthenium(II) Ammine Complexes

    OpenAIRE

    Betanzos-Lara, Soledad; Habtemariam, Abraha; Clarkson, Guy J.; Sadler, Peter J.

    2011-01-01

    Bifunctional neutral half-sandwich RuII complexes of the type [(η6-arene)Ru(NH3)Cl2] where arene is p-cym (1) or bip (2) were synthesised by the reaction of N,N-dimethylbenzylamine (dmba), NH4PF6 and the corresponding RuII arene dimer, and were fully characterised. X-ray crystallographic studies of [(η6-p-cym)Ru(NH3)Cl2]·{(dmba–H)(PF6)} (1a) and [(η6-bip)Ru(NH3)Cl2] (2) show extensive H-bond interactions in the solid state, mainly involving the NH3 and the Cl ligands, as well as weak aromatic...

  16. Facile Uptake and Release of Ammonia by Nickel Halide Ammines.

    Science.gov (United States)

    Breternitz, Joachim; Vilk, Yury E; Giraud, Elsa; Reardon, Hazel; Hoang, Tuan K A; Godula-Jopek, Agata; Gregory, Duncan H

    2016-06-01

    Although major difficulties are experienced for hydrogen- storage materials to meet performance requirements for mobile applications, alternative fuel cell feedstocks such as ammonia can be stored in the solid state safely at high capacity. We herein describe the NiX2 -NH3 (X=Cl, Br, I) systems and demonstrate their exceptional suitability for NH3 storage (up to 43 wt % NH3 with desorption that begins at 400 K). The structural effects that result from the uptake of NH3 were studied by powder X-ray diffraction (PXD), FTIR spectroscopy and SEM. NH3 release at elevated temperatures was followed by in situ PXD. The cycling capabilities and air stability of the systems were also explored. NH3 is released from the hexaammines in a three-step process to yield the diammine, monoammine and NiX2 dihalides respectively and (re)ammoniation occurs readily at room temperature. The hexaammines do not react with air after several hours of exposure. PMID:27137479

  17. Ammonia dynamics in magnesium ammine from DFT and neutron scattering

    DEFF Research Database (Denmark)

    Tekin, Adem; Hummelshøj, Jens Strabo; Jacobsen, Hjalte Sylvest;

    2010-01-01

    ) and quasielastic neutron scattering (QENS). The crystal structures of Mg(NH3)(n)Cl-2 with n = 6, 2, 1, which contains up to 9.19 wt % hydrogen and 0.115 kg hydrogen L-1, are first analyzed using an algorithm based on simulated annealing (SA), finding all the experimentally known structures and predicting the C2/m...... structure for the uncharacterized low temperature phase of Mg(NH3)(6)Cl-2. It is found from DFT that the rotation of ammonia in the hexammine complex (n = 6) requires an activation energy of 0.09 eV in the low temperature phase of Mg(NH3)(6)Cl-2 and 0.002-0.12 eV in the high temperature phases; effectively...

  18. Studio della formazione di ammine biogene e di altri composti azotati negli alimenti

    OpenAIRE

    Congiu, Francesca

    2014-01-01

    The aim of this thesis was the qualitative and quantitative determination of biogenic amines (BA) and amino acids (AA), in particular the essential AA, in different food matrices typical of Sardinia (Italy). The study was focused on wines and table olives, which are potential source of biogenic amines due to their fermentation processes involved in their production. The decision to follow this research field is based on the importance of having updated information to assess the actual r...

  19. Simultaneous neutron diffraction and microwave dielectric characterisation of ammine materials - a non-destructive, non-contact characterisation tool for determining ammonia content in solids.

    Science.gov (United States)

    Jones, Martin Owen; Hartley, Jon; Porch, Adrian

    2016-08-17

    We have investigated ammonia adsorption in group two halides (MgI2 and CaBr2) using custom-built apparatus that permits simultaneous neutron diffraction, microwave dielectric characterisation and out-gas mass spectroscopy of solid state materials during ammonia adsorption. Deuterated ammonia was flowed over the sample and the uptake - as measured by mass flow meters, mass spectroscopy and structure - compared with the change in dielectric constant. An excellent correlation between ammonia content and dielectric property was observed and, when linked to diffraction, mass flow and mass spectroscopy data, could be used to determine the amount of ammonia present within the solid. The combination of these techniques could also be used to differentiate physisorbed and metal-coordinated ammonia and explain subtleties in the observed structural transformations. PMID:27498837

  20. Accelerated DFT-Based Design of Materials for Ammonia Storage

    DEFF Research Database (Denmark)

    Jensen, Peter Bjerre; Bialy, Agata; Blanchard, Didier;

    2015-01-01

    Future energy carriers are needed in order to lower the CO2 emissions resulting from the burning of fossil fuels. One possible energy carrier is ammonia, which can be stored safely and reversibly in metal halide ammines; however, the release often occurs in multiple steps at too high temperatures...... materials is the first known high-capacity ternary metal halide ammine, which we have subsequently synthesized and confirmed the ammonia storage properties using temperature-programmed desorption (TPD)....

  1. Visualization of Metal-to-Ligand and Ligand-to-Ligand Charge Transfer in Metal-Ligand Complexes

    Institute of Scientific and Technical Information of China (English)

    Yong Ding; Jian-xiu Guo; Xiang-si Wang; Sha-sha Liu; Feng-cai Ma

    2009-01-01

    Three methods including the atomic resolved density of state, charge difference density, and the transition density matrix are used to visualize metal to ligand charge transfer (MLCT) in ruthenium(Ⅱ) ammine complex. The atomic resolved density of state shows that there is density of Ru on the HOMOs. All the density is localized on the ammine, which reveals that the excited electrons in the Ru complex are delocalized over the ammine ligand. The charge difference density shows that all the holes are localized on the Ru and the electrons on the ammine. The localization explains the MLCT on excitation. The transition density matrix shows that there is electron-hole coherence between Ru and ammine. These methods are also used to examine the MLCT in Os(bpy)(p0p)Cl ("Osp0p"; bpy=2,2'-bipyridyl; p0p=4,4'-bipyridyl) and the ligand-to-ligand charge transfer (LLCT) in Alq3. The calculated results show that these methods are powerful to examine MLCT and LLCT in the metal-ligand system.

  2. Computational investigation and design of coordination compounds for hydrogen storage

    DEFF Research Database (Denmark)

    Hummelshøj, Jens Strabo

    Two classes of high capacity hydrogen storage materials, the metal tetrahydroborates and the metal ammines, were investigated at the atomic scale using density functional theory simulations. It was shown that simple model structures could be used to asses the stabilities of complex systems. Trends...

  3. Role of NH3 in the Electron-Induced Reactions of Adsorbed and Solid Cisplatin

    NARCIS (Netherlands)

    Warneke, Jonas; Rohdenburg, Markus; Zhang, Yucheng; Orzagh, Juraj; Vaz, Alfredo; Utke, Ivo; De Hosson, Jeff Th M.; van Dorp, Willem F.; Swiderek, Petra

    2016-01-01

    The electron-induced decomposition of cisplatin (cis-Pt(NH3)(2)Cl-2) was investigated to reveal if ammine (NH3) ligands have a favorable effect on the purity of deposits produced from metal-containing precursor molecules by focused electron beam induced deposition (FEBID). Scanning electron microsco

  4. Computational Search for Improved Ammonia Storage Materials

    DEFF Research Database (Denmark)

    Jensen, Peter Bjerre; Lysgaard, Steen; Vegge, Tejs;

    . In this project we are searching for improved mixed materials with optimal desorption temperatures and kinetics, optimally releasing all ammonia in one step. We apply Density Functional Theory, DFT, calculations on mixed compounds selected by a Genetic Algorithm (GA), relying on biological principles of natural......Metal halide ammines, e.g. Mg(NH3)6Cl2 and Sr(NH3)8Cl2, can reversibly store ammonia, with high volumetric hydrogen storage capacities. The storage in the halide ammines is very safe, and the salts are therefore highly relevant as a carbon-free energy carrier in future transportation infrastructure...... selection. The GA is evolving from an initial (random) population and selecting those with highest fitness, a function based on e.g. stability, release temperature, storage capacity and the price of the elements. The search space includes all alkaline earth, 3d and 4d metals in combination with chloride...

  5. Ammonia/Hydrogen Mixtures in an SI-Engine

    DEFF Research Database (Denmark)

    Mørch, Christian Sandersen; Bjerre, Andreas; Gøttrup, Morten Piil;

    2011-01-01

    In recent years there has been increasing focus on using metal ammine complexes for ammonia storage. In this paper a fuel system for ammonia fuelled internal combustion engines using metal ammine complexes as ammonia storage is analyzed. The use of ammonia/hydrogen mixtures as an SI-engine fuel...... is investigated in the same context. Ammonia and hydrogen were introduced into the intake manifold of a CFR-engine. Series of experiments with varying excess air ratio and different ammonia to hydrogen ratios was conducted. This showed that a fuel mixture with 10 vol.% hydrogen performs best with respect...... to efficiency and power. A comparison with gasoline was made, which showed efficiencies and power increased due to the possibility of a higher compression ratio. The system analysis showed that it is possible to cover a major part of the necessary heat using the exhaust heat. It is proposed to reduce the high...

  6. Studies on the interaction of benzotriazole (a corrosion inibitor) with the ruthenium (II) (III) ammincomplexes and pentacyanoferrate (II)

    International Nuclear Information System (INIS)

    Some studies on the interaction of benzotriazole with the aquapentacyanoferrate (II), aquapentaamminruthenium (II) and cis-and trans-(NH3)4 Ru(H2O)22+ complexes are described. The reactions, substituted products and complexes production are demonstrated. The absorption bands for the ammine (benzotriazole) and ruthenium (II) complexes as well as the activation parameters and kinetics of reactions are discussed. (M.J.C.)

  7. Handheld hydrogen - a new concept for hydrogen storage

    DEFF Research Database (Denmark)

    Johannessen, Tue; Sørensen, Rasmus Zink

    2005-01-01

    A method of hydrogen storage using metal ammine complexes in combination with an ammonia decomposition catalyst is presented. This dense hydrogen storage material has high degree of safety compared to all the other available alternatives. This technology reduces the safety hazards of using liquid...... ammonia and benefits from the properties of ammonia as a fuel. The system can be used as a safe, reversible, low-cost hydrogen carrier....

  8. Crystal structure of Ag2(μ-SCN)2(NH3)4

    OpenAIRE

    Müller, Thomas G.; Florian Kraus

    2016-01-01

    Di-μ-thiocyanato-bis[diamminesilver(I)], [Ag2(μ-SCN)2(NH3)4], was synthesized by the reaction of AgSCN with anhydrous liquid ammonia. In the binuclear molecule, the AgI atom is coordinated by two ammine ligands and the S atom of one thiocyanate ligand. Two of these [Ag(SCN)(NH3)2] units are bridged by the S atoms of the thiocyanate anions at longer distances, leading to a dimer with point group symmetry C2. The distance between the AgI atoms in the dimer is at 3.0927 (6) Å within the range of...

  9. SiO2-coatings on glass containing copper colloids using the sol-gel-technique

    OpenAIRE

    Mennig, Martin; Schmitt, Mike; Kutsch, Bernd; Schmidt, Helmut K.

    1994-01-01

    A sol-gel method for the preparation of transparent copper nano particle-containing SiO2 coatings on glass has been developed. The sol is synthesised from alkoxysilanes and tetra ethyl orthosilicate with copper ammine complexes, prepared from Cu²+ salts and amino alkoxy silames. Glass substrates are coated by dipping and layers up to 1 µm in thickness are obtained after thermal densification at temperatures between 200°-500°C. The Cu colloid formation can be achieved using a reducing atmosphe...

  10. Modification of Silica Rice Husk Ash to Solid Ammonium Sulphate for Second Generation Biofuels Productions

    Directory of Open Access Journals (Sweden)

    Kasim Mohammed Hello

    2014-01-01

    Full Text Available A new approach has been demonstrated for the synthesis of solid ammonium sulphate attached to silica rice husk ash. The 3-(aminopropyltriethoxysilane was immobilized onto silica at room temperature to functionalize the silica with ammine end groups (–NH2. The amine group was sulphated with sulphuric acid to produce a novel micro-rod-like shaped acidic catalyst (as seen with TEM designated RHNH3SO4H (RH = rice husk. The TGA analysis shows that the catalyst is stable at temperatures below 200°C. The acidity measurement of the catalyst indicates that it has Brønsted acid sites. Cellulose extracted from waste of rice husk and cellulose extracted from office paper were hydrolysed to glucose in 6 h, and the glucose was hydrolysed afterwards to other products within 13 h. The catalyst is reusable many times without a significant loss of catalytic activity.

  11. Reactions of Cisplatin Hydrolytes with Thiols. 3: Reactions of cis-[Pt(15NH32(H2O2]2+ with Glutathione

    Directory of Open Access Journals (Sweden)

    Sutopo Hadi

    2006-04-01

    Full Text Available The reaction of cis-[Pt(15NH32(H2O2]2+ (3 with glutathione (GSH was investigated in aqueous solution. In this reaction, the ammine in the platinum complex formed was liberated. Surprisingly two chelate rings were observed, six-membered-S,O-chelate ring complex cis-[Pt(15NH32(SG-S,O (7 and five-membered-S,N-chelate ring complex cis-[Pt(15NH32(SG-S,N] (8. The bis (thiolate platinum(II complex, cis-[Pt(15NH32(SG2] (9 was always present in this reaction in any mole ratio used. The dinuclear sulphur-bridged complex (10, giving a broad peak in 15N NMR, was only present in very tiny amounts.

  12. Response Behaviour of a Hydrogen Sensor Based on IonicConducting Polymer-metal Interfaces Prepared by the ChemicalReduction Method

    Directory of Open Access Journals (Sweden)

    Werner Weppner

    2006-04-01

    Full Text Available A solid-state amperometric hydrogen sensor based on a protonated Nafionmembrane and catalytic active electrode operating at room temperature was fabricated andtested. Ionic conducting polymer-metal electrode interfaces were prepared chemically byusing the impregnation-reduction method. The polymer membrane was impregnated withtetra-ammine platinum chloride hydrate and the metal ions were subsequently reduced byusing either sodium tetrahydroborate or potassium tetrahydroborate. The hydrogen sensingcharacteristics with air as reference gas is reported. The sensors were capable of detectinghydrogen concentrations from 10 ppm to 10% in nitrogen. The response time was in therange of 10-30 s and a stable linear current output was observed. The thin Pt films werecharacterized by XRD, Infrared Spectroscopy, Optical Microscopy, Atomic ForceMicroscopy, Scanning Electron Microscopy and EDAX.

  13. Near-infrared emitting CdTe0.5Se0.5/Cd0.5Zn0.5S quantum dots: synthesis and bright luminescence

    OpenAIRE

    Yang, Ping; Wang, Shiquan; Murase, Norio

    2012-01-01

    We present how CdTe0.5Se0.5 cores can be coated with Cd0.5Zn0.5S shells at relatively low temperature (around 200°C) via facile synthesis using organic ammine ligands. The cores were firstly fabricated via a less toxic procedure using CdO, trioctylphosphine (TOP), Se, Te, and trioctylamine. The cores with small sizes (3.2-3.5 nm) revealed green and yellow photoluminescence (PL) and spherical morphologies. Hydrophobic core/shell CdTe0.5Se0.5/Cd0.5Zn0.5S quantum dots (QDs) with tunable PL betwe...

  14. Crystal structure of [Co(NH36][Co(CO4]2

    Directory of Open Access Journals (Sweden)

    Thomas G. Müller

    2015-11-01

    Full Text Available Hexaamminecobalt(II bis[tetracarbonylcobaltate(-I], [Co(NH36][Co(CO4]2, was synthesized by reaction of liquid ammonia with Co2(CO8. The CoII atom is coordinated by six ammine ligands. The resulting polyhedron, the hexaamminecobalt(II cation, exhibits point group symmetry -3. The Co-I atom is coordinated by four carbonyl ligands, leading to a tetracarbonylcobaltate(−I anion in the shape of a slightly distorted tetrahedron, with point group symmetry 3. The crystal structure is related to that of high-pressure BaC2 (space group R-3m, with the [Co(NH36]2+ cations replacing the Ba sites and the [Co(CO4]− anions replacing the C sites. N—H...O hydrogen bonds between cations and anions stabilize the structural set-up in the title compound.

  15. Ammonia for hydrogen storage: challenges and opportunities

    DEFF Research Database (Denmark)

    Klerke, Asbjørn; Christensen, Claus H.; Nørskov, Jens Kehlet;

    2008-01-01

    The possibility of using ammonia as a hydrogen carrier is discussed. Compared to other hydrogen storage materials, ammonia has the advantages of a high hydrogen density, a well-developed technology for synthesis and distribution, and easy catalytic decomposition. Compared to hydrocarbons...... and alcohols, it has the advantage that there is no CO2 emission at the end user. The drawbacks are mainly the toxicity of liquid ammonia and the problems related to trace amounts of ammonia in the hydrogen after decomposition. Storage of ammonia in metal ammine salts is discussed, and it is shown...... that this maintains the high volumetric hydrogen density while alleviating the problems of handling the ammonia. Some of the remaining challenges for research in ammonia as a hydrogen carrier are outlined....

  16. Bis[diamminesilver(I] 5-nitroisophthalate monohydrate

    Directory of Open Access Journals (Sweden)

    Di Sun

    2010-04-01

    Full Text Available In the title compound, [Ag(NH32]2(C8H3NO6·H2O, the cations have an almost linear coordination geometry with two ammine ligands and interact with the water molecules [Ag...Owater = 2.725 (4 and 2.985 (4 Å]. In the crystal, N—H...O and O—H...O hydrogen bonds, combined with weak (lone pair...π [O...centroid distance = 3.401 (4 Å] and π–π stacking [centroid–centroid distance = 3.975 (3 Å] interactions, stabilize the three-dimensional supramolecular network.

  17. Towards an ammonia-mediated hydrogen economy?

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Johannessen, Tue; Sørensen, Rasmus Zink;

    2006-01-01

    Materialization of a hydrogen economy could provide a solution to significant global challenges, In particular. the possibility of improving the efficiency and simultaneously minimizing the environmental impact of energy conversion processes, together with the opportunity to reduce the dependency...... of fossil fuels, are main drivers for the currently increasing research and development efforts. However. significant technological breakthroughs are necessary for making a hydrogen economy feasible. In particular, it is necessary to develop appropriate hydrogen storage and transportation technologies....... Recently, metal ammine salts were proposed as safe, reversible. high-density and low-cost hydrogen carriers. Here, we discuss how this development could provide a platform for using ammonia as a fuel for the hydrogen economy, We do that by comparing various possible hydrogen carriers with respect to energy...

  18. Crystal structure of trans-diammine(1,4,8,11-tetraazacyclotetradecane-κ4Nchromium(III tetrachloridozincate chloride monohydrate from synchrotron data

    Directory of Open Access Journals (Sweden)

    Dohyun Moon

    2016-04-01

    Full Text Available The asymmetric unit of the title complex salt, [Cr(C10H24N4(NH32][ZnCl4]Cl·H2O, is comprised of four halves of the CrIII complex cations (the counterparts being generated by application of inversion symmetry, two tetrachloridozincate anions, two chloride anions and two water molecules. Each CrIII ion is coordinated by the four N atoms of the cyclam (1,4,8,11-tetraazacyclotetradecane ligand in the equatorial plane and by two N atoms of ammine ligands in axial positions, displaying an overall distorted octahedral coordination environment. The Cr—N(cyclam bond lengths range from 2.0501 (15 to 2.0615 (15 Å, while the Cr—(NH3 bond lengths range from 2.0976 (13 to 2.1062 (13 Å. The macrocyclic cyclam moieties adopt the trans-III conformation with six- and five-membered chelate rings in chair and gauche conformations. The [ZnCl4]2− anions have a slightly distorted tetrahedral shape. In the crystal, the Cl− anions link the complex cations, as well as the solvent water molecules, through N—H...Cl and O—H...Cl hydrogen-bonding interactions. The supramolecular set-up also includes N—H...Cl, C—H...Cl, N—H...O and O—H...Cl hydrogen bonding between N—H or C—H groups of cyclam, ammine N—H and water O—H donor groups, and O atoms of the water molecules, Cl− anions or Cl atoms of the [ZnCl4]2− anions as acceptors, leading to a three-dimensional network structure.

  19. 稀有金属表面电镀铂研究现状%Current Status of Electroplating Pt on the Surface of Rare Metals

    Institute of Scientific and Technical Information of China (English)

    杜继红; 李晴宇

    2014-01-01

    Platinum coatings are prepared by electroplating platinum on the surface of rare metals. Both alkaline baths and acid baths are employed as the solution system, and main salts include different water-soluble platinum complexes of ammine, hydroxide, chloride and sulfate. The platinum coatings so obtained on rare metals are applied to water disposal, chemical technology, metallurgy, electronic technology, etc.%采用电镀的方法在稀有金属钛、钽、铌、钼表面制备铂涂层。镀铂体系主要有碱性和酸性溶液,镀液主化合物是P盐、羟基络合物、氨(胺)络合物、氯络合物、硫酸盐等。稀有金属镀铂电极主要应用于水处理、化工、冶金、电子行业等领域。

  20. Ab initio studies of transition metal complexes and related electron transfer properties

    International Nuclear Information System (INIS)

    Ab initio electronic structure calculations have been carried out for various aquo and ammine complexes of Fe, Co, and Ru in their 2+ and 3+ oxidation states. The results of these calculations are used as assessing a variety of factors controlling electron transfer kinetics including the charge-state dependence of various inner shell geometrical parameters and associated vibrational frequencies (metal-ligand and intra-ligand and intra-ligand stretching modes, and librational modes), and the dependence of electron transfer matrix elements on the nature of the ligand and the metal orbital type (/sup t/2/sub g/ vs. e/sub g/). The charge-state dependence of the OH bond lengths in hexa-aquo ions is predicted to yield H/D isotope effects (i.e., fractionation between bulk and first shell water), which should be detectable by neutron scattering experiments on appropriate aqueous solutions. The relationship between these thermodynamic isotope effects, which depend critically on strong OH triple bond O hydrogen bonding between first and second-shell water molecules, and kinetic H/D isotope effects in electron exchange involving hexa-aquo ions will be discussed

  1. Polyvinyl alcohol electrospun nanofibers containing Ag nanoparticles used as sensors for the detection of biogenic amines

    Science.gov (United States)

    Marega, Carla; Maculan, Jenny; Rizzi, Gian Andrea; Saini, Roberta; Cavaliere, Emanuele; Gavioli, Luca; Cattelan, Mattia; Giallongo, Giuseppe; Marigo, Antonio; Granozzi, Gaetano

    2015-02-01

    Polyvinyl alcohol (PVA) electrospun nanofibers containing Ag nanoparticles (NPs) have been deposited on glass substrates. The aim of the work was to test the feasibility of this approach for the detection of biogenic amines by using either the Ag localized surface plasmon resonance quenching caused by the adsorption of amines on Ag NPs or by detecting the amines by surface enhanced Raman spectroscopy (SERS) after adsorption, from the gas phase, on the metal NPs. Two different approaches have been adopted. In the first one an ethanol/water solution containing AgNO3 was used directly in the electrospinning apparatus. In this way, a simple heat treatment of the nanofibers mat was sufficient to obtain the formation of Ag NPs inside the nanofibers and a partial cross-link of PVA. In the second procedure, the Ag NPs were deposited on PVA nanofibers by using the supersonic cluster beam deposition method, so that a beam of pure Ag NPs of controlled size was obtained. Exposure of the PVA mat to the beam produced a uniform distribution of the NPs on the nanofibers surface. Ethylendiamine vapors and volatile amines released from fresh shrimp meat were chemisorbed on the nanofibers mats. A SERS spectrum characterized by a diagnostic Ag-N stretching vibration at 230 cm-1 was obtained. The results allow to compare the two different approaches in the detection of ammines.

  2. Polyvinyl alcohol electrospun nanofibers containing Ag nanoparticles used as sensors for the detection of biogenic amines

    International Nuclear Information System (INIS)

    Polyvinyl alcohol (PVA) electrospun nanofibers containing Ag nanoparticles (NPs) have been deposited on glass substrates. The aim of the work was to test the feasibility of this approach for the detection of biogenic amines by using either the Ag localized surface plasmon resonance quenching caused by the adsorption of amines on Ag NPs or by detecting the amines by surface enhanced Raman spectroscopy (SERS) after adsorption, from the gas phase, on the metal NPs. Two different approaches have been adopted. In the first one an ethanol/water solution containing AgNO3 was used directly in the electrospinning apparatus. In this way, a simple heat treatment of the nanofibers mat was sufficient to obtain the formation of Ag NPs inside the nanofibers and a partial cross-link of PVA. In the second procedure, the Ag NPs were deposited on PVA nanofibers by using the supersonic cluster beam deposition method, so that a beam of pure Ag NPs of controlled size was obtained. Exposure of the PVA mat to the beam produced a uniform distribution of the NPs on the nanofibers surface. Ethylendiamine vapors and volatile amines released from fresh shrimp meat were chemisorbed on the nanofibers mats. A SERS spectrum characterized by a diagnostic Ag–N stretching vibration at 230 cm−1 was obtained. The results allow to compare the two different approaches in the detection of ammines. (paper)

  3. Preparation of silver tin oxide powders by hydrothermal reduction and crystallization

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw marrials. H2C2O4 was used as the co-precipitator of silver ions and tin ions. The co-precipitation conditions were investigated. The results show that the co-precipitate of Ag2C2O4 and Sn(OH)4 is available when the pH value of the solution is 4.27-8.36. Using the obtained precipitate as precursor, the reduction of Ag+ and the crystallization of tin oxide were carried out simultaneonsly by the hydrothermal method and silver tin oxide composite powders were obtained. The composite powders were characterized by X-ray diffraction (XRD) analysis, scanning electron microscope (SEM), and energy spectrum analysis. The results show that the silver tin oxide composite powders are small with a diameter of about 2 μm and with homogeneous distribution of tin.

  4. Case study of the failure of supercritical water oxidation reactor tubing during the treatment of 2,4 DNP with ammonium sulphate

    International Nuclear Information System (INIS)

    During the process of Supercritical Water Oxidation (SCWO) organic chemical streams are oxidized at high temperature and pressure, typically in excess of 647 K and 22.1 MPa. Due to high operating temperatures and pressures severely corrosive environments often ensue and eventually lead to SCWO reactor tube failures. This case study looked at one such failure of Alloy 625 (61Ni-21.5Cr-9Mo) tubing which occurred at the UBC/NORAM SCWO pilot plant while treating a feed of waste water containing 2.4 wt% 2,4 dinitrophenolate, 2% ammonium sulphate and 6% excess ammonia. Although the feed pH was approximately 9 and therefore not expected to be corrosive, in fact the tube failed when exposed to this feed (with oxygen) for a period of about 1 hour at 650-655 K. Through the examination of the ensuing thermodynamic system as well as SEM and Optical Microscope analysis of the ruptured portions of tubing, it was found that the addition of ammonium sulphate to the treated media caused rapid failure due to de-alloying. Findings show that the high sub-critical temperature and high density of the feed water at failure points, as well as the corrosion morphology are consistent with attack by ammonia. The formation of a stable soluble nickel-ammine phase is suspected. (author)

  5. Recyclable epoxy resins: An example of green approach for advanced composite applications

    Science.gov (United States)

    Cicala, Gianluca; Rosa, Daniela La; Musarra, Marco; Saccullo, Giuseppe; Banatao, Rey; Pastine, Stefan

    2016-05-01

    Automotive composite applications are increasingly growing due to demand for lightweight structures to comply to the requirements for fuel reduction. HP-RTM is gaining relevance as one of the preferred production technologies for high volume applications. The BMW i3 life module being a notable example of HP-RTM application. The key aspects of HP-RTM are the short injection times (i.e. less than 1min) and the fast curing of the thermoset resins (i.e. less than 10min). The choice of using thermosets poses relevant issues for their limited recycling options. The standard recycling solution is the incineration but, this solution poses some concerns in terms of global environmental impact. Novel solutions are presented in this work based on the use of recyclable epoxy systems. In our work the results of experimentation carried out by our group with cleavable ammines by Connora Technologies and bioepoxy resins by Entropy Resins will be discussed. The multiple uses of recycled matrices obtained treating the recyclable epoxy resins are discussed in the framework of a "cradle" to "crave" approach. Finally, Life Cycle Assessment (LCA) is used to evaluate the environmental benefits of the proposed approach.

  6. The effect of anhydrite saturation on the fate of sulfur during fluid-present melting of subducting basaltic crust

    Science.gov (United States)

    Jego, S.; Dasgupta, R.

    2012-12-01

    and will be presented. [1] Kelley and Cottrell (2009), Science 325, 605-607; [2] Jégo and Dasgupta (GCA, under review); [3] Jakobsson (2012), CMP, in press; [4] Médard et al. (2008), AmMin 93, 1838-1844; [5] Balta et al. (2011), AmMin 96, 1467-1474; [6] Li and Ripley (2009), EconGeol 104, 405-412; [7] Baker and Moretti (2011), RiMG 73, 167-213.

  7. Bimetallic Pt-Ni catalysts supported on usy zeolite for n-hexane isomerization

    Directory of Open Access Journals (Sweden)

    F. V. Barsi

    2009-06-01

    Full Text Available Isomerization of linear alkanes has had considerable importance for the refining industry because the isomers formed in this reaction have high octane number. Most works reported in the literature studied the use of bifunctional catalysts, i.e., ones that have acid sites and metallic sites. In this study, bifunctional monometallic (Ni or Pt and bimetallic catalysts (Pt-Ni, using HUSY zeolite as the support, were prepared in order to verify the role of the metal content and composition on the catalytic properties for n-hexane isomerization. The method used for metal dispersion in the zeolite was competitive ion exchange using ammine complexes [Ni(NH36]Cl2 and [Pt(NH34]Cl2 as precursors. Four series of catalysts with constant atomic metal content had total metal amounts between 130 and 280 µmol M/g cat. Catalysts were characterized by temperature programmed reduction (TPR and subjected to catalytic evaluation for n-hexane isomerization at 250 ºC and 1 atm using H2/C6 = 9 molar ratio. TPR results show an easier reducibility of Ni+2 cations in the presence of Pt, which was evidenced by the displacement of the reduction peak of those cations towards lower temperatures in bimetallic catalysts. The bimetallic catalysts presented a higher activity in the isomerization of n-hexane when compared to the monometallic ones, as well better stability as the Pt content in the solid increases. The results of the activity as a function of the Pt content in the bimetallic catalysts show a maximum value around 50% of Pt. An addition of Pt above this critical value leads to a small decrease of the catalytic activity.

  8. Effect of solution temperature on methylene blue degradation in glow corona discharge reactor

    Energy Technology Data Exchange (ETDEWEB)

    Benetoli, L.O.B.; Cadorin, B.M.; Goncalves de Souza, I.; Debacher, N.A. [Federal Univ. of Santa Catarina, Florianopolis, Santa Catarina (Brazil). Dept. of Chemistry

    2010-07-01

    Non-thermal plasma (NTP) is an emerging technology for water cleaning that can be used in several environmental and industrial processes. Electrical discharges above or below the water surface cause chemical activation of a system through the production of strong oxidant species in solution that can be used to break down and remove toxic organic contaminants such as dyes, phenols or aromatic ammines that are present in the aqueous phase. This study investigated the effect of bath solution temperature on methylene blue (MB) degradation in a point-to-plate glow corona discharge (GCD) reactor. MB is used to mediate electron transfer in microbial fuel cells. The activation energy involved in the dye degradation was estimated in order to better understand the chemical processes taking place in the liquid phase triggered by the NTP discharge. The plasma channels were created in the nitrogen gas phase above the solution surface. The bath solution temperature varied between 4 to 47 degrees C. The dye removal percentage increased as the bath temperature increased except at 47 degrees C, when a decrease in the MB removal was observed. The formation of hydrogen peroxide (H{sub 2}O{sub 2}) increased as the bath temperature decreased. The maximum H{sub 2}O{sub 2} concentration was observed at 4 degrees C. This effect may be related to the viscosity and diffusion coefficients of water and dye/H{sub 2}O{sub 2} molecules. This paper also presented the activation energy of the GCD process as determined by the Arrhenius equation. 11 refs., 1 tab., 6 figs.

  9. Molecular insights into the local anesthetic receptor within voltage-gated sodium channels using hydroxylated analogues of mexiletine

    Directory of Open Access Journals (Sweden)

    Jean-François eDesaphy

    2012-02-01

    Full Text Available We previously showed that the β-adrenoceptor modulators, clenbuterol and propranolol, directly blocked voltage-gated sodium channels, whereas salbutamol and nadolol did not (Desaphy et al., 2003, suggesting the presence of two hydroxyl groups on the aromatic moiety of the drugs as a molecular requisite for impeding sodium channel block. To verify such an hypothesis, we synthesized five new mexiletine analogues by adding one or two hydroxyl groups to the aryl moiety of the sodium channel blocker and tested these compounds on hNav1.4 channels expressed in HEK293 cells. Concentration-response relationships were constructed using an holding potential of -120 mV at 0.1 Hz (tonic block and 10 Hz (use-dependent block stimulation frequencies. The half-maximum inhibitory concentrations (IC50 were linearly correlated to drug lipophilicity: the less lipophilic the drug, minor was the block. The same compounds were also tested on F1586C and Y1593C hNav1.4 channel mutants, to gain further information on the molecular interactions of mexiletine with its receptor within the sodium channel pore. Alteration of tonic block suggests that the aryl moiety of mexiletine may interact either directly or indirectly with Phe1586 in the closed sodium channel to produce low-affinity binding block, and that this interaction depends on the electrostatic potential of the drug aromatic tail. Alteration of use-dependent block suggests that addition of hydroxyl groups to the aryl moiety may modify high-affinity binding of the drug ammine terminal to Phe1586 through cooperativity between the two pharmacophores, this effect being mainly related to drug lipophilicity. Mutation of Tyr1593 further impaired such cooperativity. In conclusion, these results confirm our former hypothesis showing that the presence of hydroxyl groups to the aryl moiety of mexiletine greatly reduced sodium channel block, and provide molecular insights into the intimate interaction of local anesthetics with

  10. Fluoridonitrosyl complexes of technetium(I) and technetium(II). Synthesis, characterization, reactions, and DFT calculations.

    Science.gov (United States)

    Balasekaran, Samundeeswari Mariappan; Spandl, Johann; Hagenbach, Adelheid; Köhler, Klaus; Drees, Markus; Abram, Ulrich

    2014-05-19

    A mixture of [Tc(NO)F5](2-) and [Tc(NO)(NH3)4F](+) is formed during the reaction of pertechnetate with acetohydroxamic acid (Haha) in aqueous HF. The blue pentafluoridonitrosyltechnetate(II) has been isolated in crystalline form as potassium and rubidium salts, while the orange-red ammine complex crystallizes as bifluoride or PF6(-) salts. Reactions of [Tc(NO)F5](2-) salts with HCl give the corresponding [Tc(NO)Cl4/5](-/2-) complexes, while reflux in neat pyridine (py) results in the formation of the technetium(I) cation [Tc(NO)(py)4F](+), which can be crystallized as hexafluoridophosphate. The same compound can be synthesized directly from pertechnetate, Haha, HF, and py or by a ligand-exchange procedure starting from [Tc(NO)(NH3)4F](HF2). The technetium(I) cation [Tc(NO)(NH3)4F](+) can be oxidized electrochemically or by the reaction with Ce(SO4)2 to give the corresponding Tc(II) compound [Tc(NO)(NH3)4F](2+). The fluorido ligand in [Tc(NO)(NH3)4F](+) can be replaced by CF3COO(-), leaving the "[Tc(NO)(NH3)4](2+) core" untouched. The experimental results are confirmed by density functional theory calculations on [Tc(NO)F5](2-), [Tc(NO)(py)4F](+), [Tc(NO)(NH3)4F](+), and [Tc(NO)(NH3)4F](2+).

  11. Synthesis, characterization and molecular sensing capability of fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl] where dpktsc = di-2-pyridylketone thiosemicarbazone

    Science.gov (United States)

    Bakir, Mohammed; Brown, Ordel

    2009-07-01

    When di-2-pyridyl ketone thiosemicarbazone (dpktsc) was allowed to react with [Re(CO) 5Cl] in toluene under reflux, fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl] was isolated in good yield. The identity of fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl] was established from the results of its elemental analysis, spectroscopic, and electrochemical properties. The infrared spectra of fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl] show the facial coordination of the carbonyl groups, and the pyridyl N,N-coordination of dpktsc. 1H NMR measurements on fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl] in d6-dmso and d6-acetone confirmed the pyridyl N,N-coordination of dpktsc, and showed strong solvent dependence as manifested by the sensitivity of thioamide and ammine protons to their surroundings. The electronic absorption spectra of fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl] in protophilic solvents (dmso and dmf) display two intra-ligand charge transfer (ILCT) transitions at 476 and 360 nm and in non-protophilic solvents a single ILCT transition at 346 nm in CH 3CN and 342 nm in CH 2Cl 2. Reversible interconversion between fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl] and its conjugate base was established in protophilic solvents using a base to shift the equilibrium to the conjugate base and an acid to shift the equilibrium or conjugate base to the neutral form. Substrates in concentrations as low as 1 × 10 -10 M can be detected and determined using protophilic solutions of fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl]. When MCl 2 (M = Zn, Cd or Hg) was allowed to interact with fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl] in protophilic solvents, the intensity of the low energy ILCT band disappeared and a shift in the high energy ILCT electronic transition was observed that hints to the coordination of MCl 2 to fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl]. Electrochemical measurements on fac-[Re(CO) 3(κ 2-N,N-dpktsc)Cl] in dmf showed sequential irreversible redox processes in accord with the electrochemical reduction or oxidation of the thiosemicarbazone moiety.

  12. Oxaliplatin Binding to Human Copper Chaperone Atox1 and Protein Dimerization.

    Science.gov (United States)

    Belviso, Benny D; Galliani, Angela; Lasorsa, Alessia; Mirabelli, Valentina; Caliandro, Rocco; Arnesano, Fabio; Natile, Giovanni

    2016-07-01

    Copper trafficking proteins have been implicated in the cellular response to platinum anticancer drugs. We investigated the reaction of the chaperone Atox1 with an activated form of oxaliplatin, the third platinum drug to reach worldwide approval. Unlike cisplatin, which contains monodentate ammines, oxaliplatin contains chelated 1,2-diaminocyclohexane (DACH), which is more resistant to displacement by nucleophiles. In solution, one or two {Pt(DACH)(2+)} moieties bind to the conserved CXXC metal-binding motif of Atox1; in the latter case the two sulfur atoms likely bridging the two platinum units. At longer reaction times, a dimeric species is formed whose composition, Atox12·Pt(2+)2, indicates complete loss of the diamine ligands. Such a dimerization process is accompanied by partial unfolding of the protein. Crystallization experiments aiming at the characterization of the monomeric species have afforded, instead, a dimeric species resembling that already obtained by Boal and Rosenzweig in a similar reaction performed with cisplatin. However, while in the latter case there was only one Pt-binding site (0.4 occupancy) made of four sulfur atoms of the CXXC motifs of the two Atox1 chains in a tetrahedral arrangement, we found, in addition, a secondary Pt-binding site involving Cys41 of the B chain (0.25 occupancy). Moreover, both platinum atoms have lost their diamines. Thus, there appears to be little relationship between what is observed in solution and what is formed in the solid state. Since full occupancy of the tetrahedral cavity is a common feature of all Atox1 dimeric structures obtained with other metal ions (Cu(+), Cd(2+), and Hg(2+)), we propose that in the case of platinum, where the occupancy is only 0.4, the remaining cavities are occupied by Cu(+) ions. Experimental evidence is reported in support of the latter hypothesis. Our proposal represents a meeting point between the initial proposal of Boal and Rosenzweig (0.4 Pt occupancy) and the

  13. Fabrication of Zinc Oxide Thin Film Transistors via Low-Temperature Solution Processing%低温溶液加工法制备氧化锌薄膜晶体管

    Institute of Scientific and Technical Information of China (English)

    兰林锋; 宋威; 史文; 彭俊彪

    2015-01-01

    为适应柔性有源有矩阵有机发光二极管(AMOLED)等新型显示技术发展的需要,将低温溶液处理的氧化锌作为半导体层、电化学氧化的氧化铝钕作为栅绝缘层,制备了氧化锌薄膜晶体管(TFT).制备氧化锌半导体层所用的前驱体溶液为无碳的 Zn(OH)x-(NH3)y(2-x)+水溶液,这种氨络合物溶液制备简单、成本低,并且由于容易形成高活性的氢氧自由基,使得氨-金属之间的分解所需要的活化能较低,生成氧化锌所需的能量较小,可以在180℃的较低温度下获得氧化锌多晶薄膜.所制备的 TFT 器件的最高迁移率可达0.9 cm2/(V·s).这种低温氧化锌薄膜工艺与室温电化学氧化的栅绝缘层工艺相结合,具有温度低和迁移率高的特点,完全能与柔性衬底兼容,在柔性显示中具有很大的应用前景.%In order to meet the requirements of novel display technologies such as flexible active-matrix organic light-emitting diodes (AMOLED),thin film transistors (TFTs)are fabricated,with low-temperature solution-pro-cessed ZnO as the semiconductor layer and with electrochemical oxidized alumina neodymium as the gate dielectric layer.In the preparation of ZnO semiconductor layer,carbon-free aqueous Zn(OH)x (NH3 )y(2 -x)+ solution with low cost and fabrication simplicity is employed,and,more importantly,the energy for metal-ammine dissociation and ZnO formation is rather low thanks to the highly activated hydroxyl radicals.As a result,ZnO polycrystalline films can be realized at a relatively low temperature,namely 1 80℃.The proposed low-temperature solution-pro-cessed ZnO fabrication method combining with room-temperature electrochemically-oxidized gate dielectric layer helps achieve high mobility up to 0.9 cm2 /(V·s),and is completely compatible with flexible substrates,so that it meets the demand of flexible electronic devices well.