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  • 1990-1994  (2)
  • 1980-1984  (4)
  • 1950-1954
  • 1940-1944
  • Chemistry  (6)
  • 1
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The lifetime of cation selective carrier-PVC-membranes partially depends on the components' remaining in the membrane. An exchange of monomeric by polymeric plasticizers with low tendency to migrate lengthens the function time drastically. Other than for Na+ - and NH4+-selective membranes, it is essential for K+ - and Ca2+-selective membranes and optional for H+-selective membranes to incorporate lipophilic anions in order to make the phase transfer catalysis more efficient. The resistence to saponification of phthalic acid polyester gives H+-selective membranes a high stability of measured values even in the alkaline range.For anion selective PVC-membranes, instead of cation selective plasticizers the plasticizing qualities of a liquid charged ligand should be used.The tubular carrier-PVC-membranes of our ion selective flow through measuring systems are diffusion welded to the ends of two PVC-tubes [1] so that they are absolutely tight with no risk of potential leakage. Migration of the membrane components plasticizer and ionophore across this border as well as their extraction [2, 3] into the measuring solution [4] will naturally reduce the membrane's functionning time [5].
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Substituted Alkinyles as Axial Ligands at Hemine Like Bound Iron(III) - Incorporation into a Spectrochemical Series.Substituted lithium alkynyles Li—C≡C—R (R = tBu, Ph, p-Cl—C6H4, Me3Si, iPr3Si, Ph3Si) react with the hemine like macrocyclic iron(III) complex 6,13-di(ethoxycarbonyl)-5, 14-dimethyl-1, 4, 8, 11-tetraazatetradeca-4,6,12,14-tetraenato[2-]iron(III)-iodide (formula 2;) in tetrahydrofuran to form anionic low-spin di-adducts [fe(C≡C—R)2]-. The incorporation of the alkynyles into a spectrochemical series of the axial ligands (studied by the sharp equatorial-ligand-to-metal CT absorption band) results in the wavelength-sequence (nm): OH- (≍ 510) « N3- (≍ 625) 〈 tBu—C≡C- (664) 〈 NH3 (666) 〈 Ph—C≡C- (692) 〈 Ph—NH2 (695) 〈 Me3Si—C≡C- (698) 〈 SCN- (713) 〈 Ph3Si—C ≡ C- (716) 〈 CN- (739) 〈 4-picoline (759) 〈 pyridine (765) 〈 nicotinamide (776) 〈 methylnicotinat (788) 〈 pyrazine (798) and points to a significant π-acceptor ability of the silyl substituents.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 476 (1981), S. 62-68 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Titanium (IV) Complex with Two Coordinatively Bonded Water Molecules: [(π-C5H5)2Ti(H2O)2](NO3)2(π-C5H5)2Ti(NO3)2 and H2O react in acetone to form the diaquo complex [(π-C5H5)2-Ti(H2O)2](NO3)2 (A). An X-ray analysis shows the titanium atom to be nearly tetrahedrally coordinated. Mean values of distances: Ti—O 2.01 Å, Ti—Z 2.03 Å (Z = center of ring); angles: O—Ti—O 92.7°, Z—Ti—Z 133.6°. Anions and cations are joined by hydrogen bonds to form strands that run in the direction of the crystallographic a axis. A crystallizes in the orthorhombic space group Pnma with Z = 4 and lattice parameters at - 100°C a = 7.601(2), b = 13.458(4) and c = 13.139(4) Å.
    Notes: (π-C5H5)2Ti(NO3)2 reagiert mit Wasser in Aceton unter Bildung des Diaquokomplexes [(π-C5H5)2Ti(H2O)2](NO3)2 (A). Eine Röntgenstrukturanalyse ergibt, daß das Ti-Atom eine annähernd tetraedrische Koordination besitzt. Mittelwerte der Abstände: Ti—O 2,01 Å, Ti—Z 2,03 Å (Z = Ringzentrum); Winkel: O—Ti—O 92, 7°, Z—Ti—Z 133,6°. Die Anionen und Kationen sind entlang der kristallographischen a-Achse durch Wasserstoffbrücken zu Strängen verknüpft. A kristallisiert in der orthorhombischen Raumgruppe Pnma mit Z = 4 und den Gitterkonstanten bei — 100°C a = 7,601(2), b = 13,458(4) und c = 13,139(4) Å.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 479 (1981), S. 113-118 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structural Chemistry of Organotitanium Compounds: Structure of [(π-C5H5)2Ti(NO3)]2OCareful hydrolysis of (π-C5H5)2Ti(NO3)2 in tetrahydrofuran yields crystals of [(π-C5H5)2Ti(NO3)]2O (A). Crystal data of A: monoclinic, space group P21/c; lattice constants: a = 12.656(4), b = 10.181(5), c = 16.197(3) Å, ß = 93.57(3)º, Z = 4. As an X-ray analysis shows, the NO3 groups act as monodentate ligands with Ti—O distances of 2.085 and 2.059 Å. The ligands are arranged in a nearly tetrahedral way around the Ti atoms. The bond angle at the bridging O atom is 171.8º.
    Notes: Bei der vorsichtigen Hydrolyse von (π-C5H5)2Ti(NO3)2 in Tetrahydrofuran entsteht der Zweikernkomplex [(π-C5H5)2Ti(NO3)]2O (A) Kristalldaten von A: monoklin, Raumgruppe P21/c; Gitterkonstanten: a = 12,656(4), b = 10,181(5), c = 16,197(3) Å, ß = 93,57(3)º und Z = 4. Eine Röntgenstrukturanalyse ergibt, daß die Nitratgruppen als einzähnige Liganden mit Ti—O-Abständen von 2,085 und 2,059 Å fungieren. Die Ti-Atome weisen eine annähernd tetraedrische Koordination auf. Der Winkel am Brücken-O-Atom beträgt 171,8º.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Advances in Polymer Technology 4 (1984), S. 51-60 
    ISSN: 0730-6679
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Modern, trend-setting small injection molding machines should be designed so that they open up new applications to the plastics processor through utilization of microelectronics. In the sector of control, it would be equivalent to stagnation if only the familiar functions were realized with modern control circuits of a higher integration level and if the possibilities of these modules were not utilized to simplify operation, to expand the technological possibilities, and to illustrate the sequences of processes. The mechanical and hydraulic designs should be adjusted to these requirements.The design and extent of the electronic control system should be such as to ensure an economically reasonable relation between extra price and additional benefit - a basic requirement for offering standard supplies.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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