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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Langmuir 11 (1995), S. 4596-4597 
    ISSN: 1520-5827
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 107 (1985), S. 2988-2990 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Advances in science and technology Vol. 51 (Oct. 2006), p. 20-29 
    ISSN: 1662-0356
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Natural Sciences in General , Technology
    Notes: Nanocrystalline TiO2 (anatase) has attracted considerable interest for applications inphotoelectrochemical solar cells. This device is based on charge injection from photoexcitedorganometallic dye which is adsorbed on the TiO2 surface. Titanium dioxide can electrochemicallyaccommodate Li+ which is useful for a design of new Li-ion batteries. Whereas the charge storagein anatase or rutile is based on the Li-insertion into the bulk crystal, the monoclinic TiO2(B)exhibits an unusual pseudocapacitive Li-storage mechanism. The photoelectrochemical and Liinsertionactivity of mesoscopic TiO2 depend significantly on the electrode morphology
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 94 (1990), S. 5127-5134 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 97 (1993), S. 9493-9498 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 110 (1979), S. 593-600 
    ISSN: 1434-4475
    Keywords: Ferrous phosphites, coordination sphere ; Hydrogen bonding ; Raman spectroscopy ; IR spectroscopy ; Magnetic susceptibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Ferrous phosphites FeHPO3·3 H2O, FeH2P2O5, FeH4P2O6·1/2 H2O and FeH10P4O12·4 H2O were studied using X-ray powder patterns, thermography, electron reflectance spectroscopy, magnetic susceptibility measurements andRaman and infrared molecular spectra. The results obtained indicate that all the phosphites studied contain an approximately octahedral coordination sphere consisting of oxygen atoms, which produces a weak crystal field around the iron atom. Phosphite FeHPO3·3 H2O contains an HPO3 2− anion with the symmetry decreased from point groupC 3v toC s. Ferrous diphosphite FeH2P2O5 contains a non-linear P−O−P bond with a valence angle of 159°. The hydrogen bonds between the water molecule and the HPO3 2− anion indicate a positive hydratation of the phosphite anion. Medium-strong or strong hydrogen bonds, 258–270 pm long, correspond to mutual interactions of the anions in the crystal lattice of hydrogenphosphites. Hydrogen bonding in hydrogenphosphites causes a decrease in theDq values.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solid state electrochemistry 1 (1997), S. 83-87 
    ISSN: 1433-0768
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The insertion of Li+ into mesoscopic TiO2 (anatase) electrodes was studied using cyclic voltammetry combined with the in situ gravimetric monitoring of the electrode mass in LiClO4 and Li(CF3SO2)2 N/propylene carbonate (PC)-based solutions. The insertion of Li+ takes place at potentials less than 2.0 V vs Li/Li+. The cathodic process is associated with a mass uptake; the subsequent oxidation process is associated with a mass decrease. The apparent molar mass of the inserted/extracted material is, however, remarkably different from that expected for the simple insertion/extraction of unsolvated Li+ ions. For a more accurate description of the behaviour of the mesoscopic anatase electrodes, we consider them as gold electrodes modified with a porous film. Thus, the mesoscopic anatase electrode behaves similarly to a polymer-modified electrode, i.e. the overall process includes coupled electron/ion transfer (insertion of Li+) and a transfer of neutral species. Analysing the EQCM (electrochemical quartz crystal microbalance) data, one can conclude that the controlling step of the insertion/extraction of Li+ into/from anatase electrodes is a coupled electron/ion transfer or the transfer of neutral species in solutions containing ClO4 − and (CF3SO2)2N− respectively.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 106 (1975), S. 1499-1512 
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Iron(III) phosphites, vic. Fe2(HPO3)3·9 H2O, FeH3P2O6·3 H2O, FeH6P3O9·H2O and Fe4H33P15O45·6 H2O were studied by means of powder X-ray, thermographic, IR and UV spectroscopy methods and by measurement of magnetic susceptibility. From the results obtained, and from analogy with phosphites studied earlier, the following structural model can be proposed: in the compounds studied, every iron atom is surrounded by six oxygen atoms of the water molecules and phosphite or, polyorthophosphite anions which form a weak ligand field of approximately octahedral symmetry. In Fe2(HPO3)3·9 H2O, symmetry of the anion is decreased from the point group C3v to the Cs group. This anion is characterised by two bonding distances between phosphorus and oxygen atoms,r PO=1,46 Å andr PO 2=1,50 Å, the respective force constants beingK PO=8.7 mdyn/Å andK PO2=7.1 mdyn/Å. Three types of hydrogen bonds occur in the crystal lattices of the compounds studied. The weakest bond (bond lengthr=2.86–2.88 Å, bond energyE=4.6–5.0 kcal/bond) is formed between molecules of hydrate water, its energy approaching that of the hydrogen bond in liquid water. The stronger hydrogen bond (r=2.67–2.70 Å,E=5.7 to 8.0 kcal/bond) is found between water molecules and phosphite or polyorthophosphite anions. The strongest hydrogen bond (r=2.55–2.64 Å) is formed by polyorthophosphite anions, linking hydroxyl groups to oxygen atoms bound to different phosphorus atoms.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Elektrochemische Charakterisierung der Permeabilität und Enthaftung plasmapolymerisierter Herxafluoropropenschichten auf PlatinMit der Methode der Plasmapolymerisation wurden aus Hexafluoropropen dünne “Polymer”-schichten auf Platinelektroden aufgebracht. Diese beschichteten Elektroden dienten als Modellsystem für die Untersuchung hydrophober organischer Schutzschichten auf Metallen. Die Enthaftung der Schichten unter dem Einfluß wäßriger Schwefelsäure wurde aus der Zeitabhängigkeit der elektrochemischen Impedanz, aus der Geschwindigkeit elektrochemische Durchtrittsreaktionen und aus der zur Pt-H-Bildung verbrauchten elektrischen Ladung abgeleitet. Es wird gezeigt, daß die Bindungen zwischen der organischen Matrix und dem Substrat durch Wasserstoff aufgebrochen werden. Die Permeabilität der Filme für H2, O2 und Fe2+/3+ wurde über die Kinetik der entsprechenden Elektrodenprozesse an den beschichteten Elektroden in verschiedenen Zuständen der Unterwanderung bestimmt.
    Notes: Plasma-polymerized hexafluoropropene films on platinum electrodes are studied as a model system for hydrophobic organic protective coatings on metals. The loss of adhesion of the films in aqueous H2SO4 is determined from the time-dependent impedance, from the rate of charge-transfer reactions, and from the Pt-H adsorption charge of the coated electrodes. It is shown that hydrogen leads to fast splitting of the platinum-polymer bonds. The permeability of the films for H2, O2, and Fe2+/3+ is determined by measuring the rates of electrochemical oxidation or reduction of these species on the coated electrodes in different states of delamination.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 238 (1996), S. 165-175 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: PTFE (Pulver oder Folien) wurde mit Alkyl- und Aryllithium in Gegenwart von Tetramethylethylendiamin (TMEDA) bei erhöhter Temperatur in einem Schritt defluoriert und derivatisiert. Die Anknüpfung von C4H9-, C8H17-, C12H25- oder Phenylgruppen an die teilweise defluorierte makromolekulare Kette wurde mit IR- und XPS-Spektroskopie sowie Elementaranalysen nachgewiesen. Die Einwirkung von Dilithiumaryl- oder Dilithiumalkylverbindungen auf PTFE unter identischen Reaktionsbedingungen führte vermutlich zu über die Alkyl- oder Arylgruppen vernetzten Polymerketten. Beim Einsatz von konzentrierten RLi-Lösungen (〉3 M) bei Temperaturen 〉150°C verläuft die Reaktion auch ohne TMEDA. Es bildet sich ein fast fluorfreies nichtalkyliertes Produkt. Die Reaktion unter Zugabe von TMEDA verläuft über eine Eliminierung und eine nukleophile Addition. Dagegen verläuft die Einwirkung konzentrierter Lithiumverbindungen ohne TMEDA über einen radikalischen Mechanismus.
    Notes: PTFE (powder or foils) was defluorinated and derivatized in a one-step process by alkyl- and aryllithium in the presence of tetramethylethylenediamineSystematic name: 1,2-Bis-[dimethylamino]ethane. (TMEDA) as a catalyst. As evidenced by infrared (IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and elemental analysis the C4H9-, C8H17-, C12H25- or phenyl groups were attached to a partly defluorinated macromolecular chain. Analogous reactions with dilithioaryl or dilithioalkyl agents presumably lead to crosslinking of the polymeric chains through alkyl or aryl groups. When the PTFE powder is treated with more concentrated RLi (〉3 mol L-1) at temperatures 〉150°C, the defluorination is almost quantitative even in the absence of the catalyst. The TMEDA-catalyzed reaction proceeds via elimination and nucleophilic addition. On the other hand, more concentrated RLi in the absence of the catalyst seems to react via a radical mechanism.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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