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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 23 (1992), S. 197-200 
    ISSN: 0933-5137
    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: A Laser-Interferometer for Non-contacting Measurements of Displacements in the Range of NanometersA prototype laser-interferometer with a computer-aided control and evaluation system was developed and attached to a commercial tensile testing equipment for testing. With microhardness indentations as markers it is possible to determine displacement changes with a resolution of about one nanometer. The capabilities of this test system are demonstrated e.g. by measurements of the static Young's modulus, the determination of the crack opening behaviour and the coefficient of thermal expansion of Cu-specimens.
    Notes: Ein Laser-Interferometer mit einem rechnergestützten Auswerteverfahren wurde in einer Prototypentwicklung an eine kommerzielle Zugprüfmaschine angepaßt und erprobt. Mit Hilfe von als Meßmarken dienenden Mikrohärteeindrücken erlaubt dieses Meßsystem. Abstandsänderungen mit einer Auflösung von etwa 1 Nanometer zu bestimmen. Die Funktionsfähigkeit dieser Meßanordnung wird an Beispielen der E-Modulmessung der Bestimmung des Rißöffnungsverhaltens und des Wärmeausdehnungs-koeffizienten von Cu-Proben demonstriert.
    Additional Material: 5 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 197 (1992), S. 185-199 
    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: PET- und PA 66-Textilien wurden unter normalen Bedingungen mit verschiedenen Dispersionsfarbstoffen gefärbt. Die gefärbten Textilien wurden mit 180 kV Elektronenstrahlung bestrahlt. Es wurde beobachtet, daß, verglichen mit den unbestrahlten Materialien, zunehmende Strahlungsdosen zu einer Zunahme des Gesamtfarbabstandes dE führten. Diese Farbunterschiede werden hauptsächlich von zwei Reaktionen verursacht: Erstens von der reversiblen Bildung von Farbstoffradikalen, die (an Luft) wieder zu den Ausgangsfarbstoffen reoxidiert werden können und zweitens durch die irreversible Reaktion von Farbstoffmolekülen mit dem Faserpolymeren. Die zweite Reaktion ruft eine permanente Farbänderung des Textils hervor, die bei entsprechenden Bestrahlungsbedingungen klein gehalten werden kann. Die Entscheidung, ob diese Veränderung toleriert werden kann, hängt von der weiteren Verwendung des Textils ab.
    Notes: PET and PA 66 fabrics were dyed with different disperse dyes under regular conditions. The dyed fabrics were irradiated with 180 kV electron radiation. It was observed that increasing radiation doses led to increasing total color differences dE if compared to the unirradiated materials.These color differences are mainly caused by two types of reactions. First by the reversible formation of dye radicals, which can be reoxidized (in air) to the original dye molecules, and second by the irreversible reaction of dye molecules with the fiber polymer. The latter reaction causes a permanent change of the color of the fabric, which can be kept low with the proper irradiation conditions. The decision whether or not this change can be tolerated depends on the further use of the textile.
    Additional Material: 12 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 2417-2422 
    ISSN: 0009-2940
    Keywords: Organosodium compounds ; Fluorenide carbanions ; Solvatation effects ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monomeric, Tetrameric, and Polymeric Sodium Fluorenide · S [S = Me2N(CH2)2N(Me)(CH2)2NMe2, Me2N(CH2)nNMe2 (n = 2, 3)]The metallation of fluorene with sodium butanide (NanBu) in the presence of N bases yields solvated sodium fluorenide. Base adducts with bi- and tridentate N-chelating ligands have been isolated: Na(fluorenide)(pmdta) (1 [PMDTA = Me2N(CH2)2N(Me)(CH2)2NMe2], [Na(fluorenide)(tmeda)]n (2) [TMEDA = Me2N(CH2)2N(Me)(CH2)2NMe2], [Na(fluorenide)(tmeda)]4) (3) [TMPDA = Me2N(CH2)3NMe2]. According to X-ray diffraction studies monomeric (1), polymeric (2), and cyclic-tetrameric (3) structures are present in the crystal. These pronounced structural variations are explained on the basis of ionic contact aggregates where together with coulomb interactions the steric requirements of the ligands become rather important. Contact distances between Na ions and several C atoms of the carbanion may vary (ca. 260 - 300 pm) and definite coordination numbers become meaningless.
    Additional Material: 4 Ill.
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  • 4
    ISSN: 0009-2940
    Keywords: Zirconium porphyrins ; Hafnium porphyrins ; Porphyrin double-deckers ; Metal bisporphyrinates ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electrochemical oxidation of zirconium and hafnium double-deckers M(P)2 (M=Zr, Hf; P=OEP, TPP) (Scheme 1)2) leads to mono- and dications which show near infrared absorption bands which are of ≈ 2000 cm-1 higher energy than those of the corresponding cerium double-decker cations. [Zr(OEP)2]X, [Zr(OEP)2]X2, and [Zr(TPP)2]X (X=ClO4- and PF6-) are isolated after electrochemical oxidation and are characterized by IR and NMR spectroscopy. Magnetic susceptibility measurements (2 K 〈 T 〈 300 K) of the solids confirm the strong coupling of the electron spins in the diamagnetic dication salt [Zr(OEP)2][ClO4]2. The molecular structure of Zr(OEP)2 is elucidated by an X-ray structural analysis.
    Additional Material: 5 Ill.
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  • 5
    ISSN: 0009-2940
    Keywords: Zirconium porphyrins ; Hafnium porphyrins ; Porphyrin double deckers ; Metal bisporphyrinates ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of new zirconium and hafnium bisporphyrinate double deckers M(P)2 (M=Zr, Hf; P=OEP, TPP)2,3) is described. The complexes are characterized by UV/Vis/NIR and 1H-NMR spectroscopy and cyclic voltammetry. As compared with M=Ce, the redox potentials or the energies of the nearinfrared absorption bands of the corresponding radical cations [M(P)2]+ are lower by ≍ 0.2 V or higher by ≍ 2000 cm-1, respectively, Hence, there is a stronger π-π interaction between the porphyrin ligands as compared with the cerium analogues due to the smaller ionic radii of Zr(IV) and Hf(IV). X-ray crystallography of Zr(TPP)2 confirms the sandwich-like structure of the compound and the close proximity of the porphyrin ligands.
    Additional Material: 4 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 2247-2253 
    ISSN: 0009-2940
    Keywords: Rhenium(V) porphyrins ; Nitridorhenium(V) complexes ; Rhenium-Nitrogen triple bonds ; Metalloporphyrins ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oxorhenium(V) porphyrins ReO(P)X (X = Cl, Br) or [ReO(P)]2O, or trichlororhenium(V) porphyrins ReCl3(P) (P = OEP, TPP, TTP, TAP, TCIP, TMP)2,3, respectively, are transformed into nitridorhenium(V) porphyrins ReN(P) with hydrazine hydrate in the presence of ethanol, in good yields. The diamagnetic complexes are stable towards hydrolysis and contain pentacoordinate ReV in a square pyramid of nitrogen donor atoms. Their structure is deduced spectrometrically and is proven in the case of ReN(OEP) by X-ray crystallography. The UV/Vis- and 1H-NMR spectra of the new nitrido complexes are compared with those of the corresponding zinc(II) porphyrins.
    Additional Material: 3 Ill.
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  • 7
    ISSN: 0009-2940
    Keywords: Methyl lithium (deuterated)/Neutron diffraction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Metal Alkyl und Aryl Compounds, 40% - Structure Refinement of Methyl Lithium by Neutron Diffraction of (LiCD3)4 at 1.5 and 290 KThe structure of deuterated methyl lithium has been refined by neutron powder diffraction at 1.5 and 290 K. At both temperatures a cubic body-centered arrangement of (LiCD3)4 units (Td, symmetry) is found. In agreement with previous X-ray powder investigations (290 K) each tetramer contains a distorted cubic Li4C4 core with pyramidal methyl groups in staggered positions with respect to the adjacent Li3 unit. Refined values, in particular precise D positions, have now been obtained.
    Additional Material: 3 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 535-539 
    ISSN: 0009-2940
    Keywords: Dithietanes, fluoro- and fluorooxo-; formation of, cleavage with halogen fluorides, gas phase structure ; Lewis acids, containing fluorine ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fluoro- and Fluorooxodithietanes (1) was isolated from the reaction of 2,2,4,4-tetrafluoro-1,3-dithietane (3) with CIF in an unpassivated monelcylinder. The hydrolysis of 1 gives (2): the trans derivative (2b) and the cis isomer (2a) are formed in a 4:1 ratio. (7) is oxidized by CIF at room temperature to give the known (8) in 87% yield. At 50°C from 8 and (9) is formed besides the ring cleavage products CF3SO2CF2SF4Cl (10) and CF3SO2CF2SF5 (11). The gasphase structure of 9 (e.d.) is described. (5) and (13) coordinate by the oxygen of the SO group to AsF5, with an unstable sulfonium salt is formed, while from the reaction of AsF5 and SbF5 with 8 (15 a, b, M = As, Sb) are isolated.
    Additional Material: 2 Ill.
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  • 9
    ISSN: 0009-2940
    Keywords: Methylsodium (deuterated) ; Neutron diffraction ; Synchrotron radiation diffraction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Metal Alkyl and Aryl Compounds, 441) - Preparation and Structure of Methylsodium. Structure Determination using NaCD, Powders at 1.5 and 300 K by Neutron and Synchrotron Radiation Diffraction[D3]Methylsodium (NaCD3) has been obtained by the reaction of [D3]methyllithium with sodium tert-butoxide. Its crystal structure has been determined from NaCD3 powder samples using the combination of neutron and synchrotron radiation diffraction techniques. Studies at 1.5 and 300 K show a new structure type (orthorhombic, space group I222, Z=16). Na and C atomic positions have been obtained from synchrotron radiation data and subsequently D positions by neutron diffraction. The complete structure has been refined using Rietveld methods. - Half of the ions are arranged in tetramers, (NaCD3)4, similar to those in methyllithium. The orientation of the methanide ions with respect to the three next Na ions is staggered. The remaining 8 Na and 8 methanide ions interconnect the tetramers by Na-C contacts; their Na ions are arranged in zigzag chains. Thus, the structure of methylsodium shows elements of the methyllithium and methylpotassium structure. All methanide ions are trigonal-pyramidal with C-D 109 pm and D-C-D angles of 106° (1.5 K). Na-C distances vary from 253 to 291 pm, depending upon the methyl-Na orientation. IR data of NaCD3 are given.
    Additional Material: 6 Ill.
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  • 10
    ISSN: 0009-2940
    Keywords: Organosodium compounds ; Aromatic carbanions ; Solvation effects ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On Alkyl- and Arylmetall Compounds, 53[11]. - Synthesis and Structure of [9,10-Dihydroanthracenylsodium(tmeda)]n and [9,10-Dihydroanthracenylsodium(pmdta)] (tmeda = tetramethylethylenediamine, pmdta = pentamethyldiethylenetriamine)The metalation of 9,10-dihydroanthracene with n-butylsodium (nBuNa) in the presence of the N bases Me2-NCH2CH2NMe2 (tmeda) and Me2NCH2CH2N(Me)CH2-CH2NMe2 (pmdta) yields the solvated 9,10-dihydroanthracenylsodium-base adducts 1 and 2, respectively. According to X-ray diffraction studies the tmeda adduct 1 is a linear polymer in the solid state whereas the pmdta adduct 2 is monomeric.
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