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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 7 (1963), S. 1451-1469 
    ISSN: 0021-8995
    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 , Physics
    Notes: Allyl glycidyl ether and maleic anhydride, mixed in equimolar quantities, cure together readily in the presence of air, peroxide, and/or Lewis acids. Outstanding properties of the castings formed are hardness (Barcol 50-60 at 25°C., 30 at 150°C.), clarity and heat distortion temperature (165-168°C.). Color is yellow to amber, and strength properties are adequate. Water resistance is fair. The mixture is too thin for convenient use in laminating, but it can be bodied by heating (1 hr., 110°C.), giving a syrup of 50 cpoise. In glass cloth laminates, through-cure appears to be inhibited by the glass. The addition of styrene overcomes this effect. Small amounts are best (5-20%), since large quantities impair elevated temperature strength. Unusually good strength is attained even at 500°F., but resistance to aging at 500°F. is poor.
    Additional Material: 7 Ill.
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  • 2
    ISSN: 0947-6539
    Keywords: coordination polymers ; Prussian blue ; rhodium ; structure elucidation ; tin ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The new coordination polymer [(Me3SnIV)3RhIII(SCN)6] = 3∞[Rh{μ-(SCNSnMe3NCS)}3] (5) is readily accessible by straightforward self-assembly of [Rh(SCN)6]3- and (dehydrated) {Me3Sn}+aq ions. The architecture of 5 is strongly reminiscent of “super-Prussian-blue” systems reported earlier: there is a three-dimensional (3-D) framework involving {Rh8} pseudocubes as the basic building blocks, the Rh3+ ions being held apart by novel, nonlinear {SCN-SnMe3-NCS} spacers (d(Rh…Rh) = 1.27 nm). The complete lattice consists of two equivalent and independent, ideally interwoven 3-D frameworks. Three homologues of 5 with slightly modified R3Sn units (R = Et, nPr and nBu) have been prepared as well, but display X-ray powder diffraction patterns notably different from that of 5.
    Additional Material: 7 Ill.
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  • 3
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1H N.M.R. Study of the Molecular Structure and Conformational Mobility of Paramagnetic Organometallic Alkoxy-uranium(IV) Complexes: Tris(cyclopentadienyl)-n-hexyloxy-, -cyclohexyloxy-, and -cholesteryloxy-uranium(IV)The properties, particularly the 1H n.m.r. spectra of three new organometallic complexes (C5H5)3UOR with R = n-hexyl-, cyclohexyl- and cholesteryl- (1-3) are described. The large paramagnetic shifts in the 1H n.m.r. spectra induced by the UIV ion give rise to discrete signals for each CH2 and CH3 group of the open chain substituent as well as for each single proton of the cyclohexane and the cholesterol ring A. In the rigid cholesterol complex the signals can be assigned by comparing their paramagnetic shifts with the geometric factors of the protons as determined from a molecular model. Thence it is concluded that the shifts of all protons except the α-protons are of the pseudocontact type. The U-O-C group appears to be strongly bent, thus inhibiting the rotation around the O-C-axis in the cholesterol complex. The paramagnetic shifts of the α-protons of all three complexes can only be accounted for by assuming an additional Fermi contact contribution of the same (negative) sign as the pseudocontact shift. The ring inversion of the C6H11 ring in the cyclohexyl complex also is strongly hindered, with a lower limit for the ΔG° value of 2.3 kcal/mole.
    Notes: Die Eigenschaften, insbesondere die 1H-NMR-Spektren, dreier neuer metallorganischer Komplexe (C5H5)3UOR mit R = n-Hexyl-, Cyclohexyl- und Cholesteryl- (1-3) werden beschrieben. Die 1H-NMR-Spektren der Alkylreste werden durch den Paramagnetismus des UIV-Ions derart aufgefächert, daß jede CH2- und CH3-Gruppe des offenkettigen Substituenten bzw. jedes einzelne Proton im Cyclohexanring bzw. im Cholesterinring A ein diskretes Signal ergibt. Die Signale der Protonen am starren Cholesteringerüst lassen sich aufgrund ihrer am Modell bestimmten Geometriefaktoren zuordnen. Daraus wird geschlossen, daß ihre paramagnetischen Verschiebungen mit Ausnahme der des α-Protons allein auf Pseudokontakt-Wechselwirkung beruhen. Die U-O-C-Anordnung erweist sich dabei als stark gewinkelt, so daß im Cholesterin-Komplex eine Rotation um die O-C-Achse infolge sterischer Behinderung unmöglich ist. Die Verschiebungen der α-Protonen der drei Komplexe lassen sich dagegen nur deuten, wenn man zusätzlich einen starken, dem Pseudokontakt-Anteil gleichgerichteten (negativen) Fermi-Kontakt-Beitrag annimmt. Die Beweglichkeit des C6H11-Rings im Cyclohexyl-Komplex ist ebenfalls stark behindert. Als unterer Grenzwert für den ΔG°-Wert der Ringinversion ergibt sich 2.3 kcal/Mol.
    Additional Material: 7 Ill.
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  • 4
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1H N.M.R. Study of the Ring Inversion of a Monosubstituted Cyclohexane by Means of a Paramagnetic Lanthanide Ion in the Substituent: Triscyclopentadienyl-(cyclohexylisonitrile)-praseodymium(III)It has been demonstrated that the 1H n.m.r. spectrum of the new organometallic C6H11X-system (C5H5)3PrIIICNC6H11 (CNC6H11 = cyclohexyl isonitrile) is so favourably modified by the action of the paramagnetic PrIII-ion that variable-temperature n.m.r. measurements provide here a new direct way for effective conformational analyses. Whereas at room temperature rapid C6H11-ring inversion gives rise to seven discrete cyclohexyl-proton lines, a total of thirteen well-separated signals appears at - 70°C. The low temperature spectrum is consistent with the predictions for two slowly inverting conformers whose Pr—C ≡ N—CRing-arrangement is linear or only slightly bent. As is further expected the coalescence temperatures of corresponding proton pairs in the conformers are not equal. Since all paramagnetic C6H11-shifts can be interpreted in terms of pseudocontact interactions, a complete assignment of all signals was possible. The ΔG-value of the ring inversion was found to be 282 ± 15 cal/mole.
    Notes: Am Beispiel des neuen metallorganischen Komplexes (C5H5)3PrIIICNC6H11 = (CNC6H11 Cyclohexylisonitril) wird gezeigt, daß die Temperaturabhängigkeit des „paramagnetisch aufgefächerten“ 1H-NMR-Spektrums dieses C6H11X-Systems sehr vorteilhaft zu dessen direkter Konformationsanalyse herangezogen werden kann. Während bei Raumtemperatur im Sinne einer sehr raschen C6H11-Ringinversion sieben diskrete C6H11-Signale auftreten, sind bei - 70° deutlich sämtliche dreizehn mit dem Fall einer linearen oder nur ganz schwach gewinkelten Pr—C≡N—CRing-Gruppierung vereinbaren Signale erkennbar. Die Koaleszenztemperaturen korrespondierender Protonenpaare der zwei Konformeren fallen hier erwartungsgemäß nicht zusammen. Die „paramagnetischen Verschiebungen“ der C6H11-Protonen lassen sich praktisch allein auf sog. Pseudokontakt-Wechselwirkungen zurückführen, so daß eine vollständige Zuordnung aller Signale vorgenommen werden konnte. Der ΔG-Wert der Ringinversion ergibt sich zu 282 ± 15 cal/Mol.
    Additional Material: 3 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 116-127 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dialkyl- and Diarylphosphinocyclooctatetraenes: A New Class of Compounds of Relevance for Conformational Analysis and Coordination ChemistryMonosubstituted cyclooctatetraenes of the type C8H7PR2 (with R = C2H5, t-C4H9. and C6H5) have been prepared for the first time and characterized both by their chemical properties and spectra. The temperature dependence of the NMR spectra of the tert-butyl compounds C8H7P- (t-C4H9)2 and [C8H7P(t-C4H9)2CH3] I, which exhibit satisfactory thermal stabilities, leads to detailed insights into the dynamics of the migration of the double bonds, of the ring inversion, and of the rotation around the (ring-)C—P bond.
    Notes: Monosubstituierte Cyclooctatetraene des Typs C8H7PR2 mit R = C2H5, t-C4H9 und C6H5 wurden erstmals dargestellt und chemisch sowie spektroskopisch charakterisiert. Die Temperaturabhängigkeit der NMR-Spektren der thermisch genügend stabilen tert-Butylverbindungen C8H7P(t-C4H9)2 und [C8H7P(t-C4H9)2CH3] I liefern Einblicke in die Dynamik der Doppelbindungsverschiebung, der Ringinversion und der Rotation um die (Ring-)C — P-Bindung.
    Additional Material: 2 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 44 (1960), S. 155-172 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The reaction of monoanhydrides and terminal epoxides to give linear polyesters is 98-99% specific in the presence of tertiary amines. Products with molecular weights up to 18,400 have been obtained; the only termination reaction detected (within the limits of analytical accuracy) has been due to hydroxyl-containing impurities in the reagents. With most epoxides the products are mixtures of stereoisomers which soften below 100°. Ethylene oxide, however, gives highly crystalline products melting at 110° to 163-165°, depending on the anhydride. Cyclohexene oxide also gives products softening higher than 110°. The use of functional epoxides gives polyesters with side-chains modifying their physical and chemical properties. Up to 30 mole-% of maleic anhydride has been incorporated, giving styrene-compatible structural polyesters. Within limits, the rate, molecular weight, and product composition are independent of the monomer concentrations. The degree of specificity drops to ca. 80% with cyclohexene oxides and to ca. 60% with alkyl epoxy stearates.
    Additional Material: 8 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 92 (1959), S. 3214-3222 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Durch Umsetzung höher kondensierter Aromaten und Biphenyl mit Cr(CO)6 wurden Phenanthren-, Anthracen- und Chrysen-chrom-tricarbonyl und die gelben Chromatricarbonyl-Komplexe des 9.10-Dihydro-anthracens und des Biphenyls dargestellt. Eigenschaften sowie spektroskopische Befunde werden angegeben, die Stellung des Cr(CO)3-Restes innerhalb der kondensierten Ringsysteme wird diskutiert.
    Additional Material: 1 Tab.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 93 (1960), S. 165-175 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die systematische Untersuchung der ν-CO-Banden an Derivaten des C6H6Cr(CO)3 und C5H5Mn(CO)3 hinsichtlich Zahl und Lage der Absorptionen führt, vor allem in Verbindung mit den Dipolmomenten, zu Einblicken in die Bindungsverhältnisse der Komplexe. Das verschieden tiefe Eingreifen des Ring-π-Elektronensextetts in die Metall-Orbitals, die Polarität der Verbindungen sowie der Metall… C- und C…O-Bindungsgrad stehen in Zusammenhang mit diesen Größen. Selbst funktionelle Gruppen am koordinativ gebundenen Fünf- und Sechsring beeinflussen noch die ν-CO-Frequenz auf charakteristische Weise, so daß eine elektronische Wechselwirkung zwischen dem Ringsubstituenten und den CO-Gruppen über das Zentralatom hinweg anzunehmen ist. Eine Verteilung der negativen Formalladung des Metallatoms auf die Liganden und eine damit zusammenhängende Vorstellung von dem Zustandekommen des Dipolmoments werden erörtert.
    Additional Material: 4 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 37 (1965), S. 1139-1143 
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Um für die Abgasentgiftung von Fahrzeugmotoren ein Gerät zur katalytischen Nachverbrennung zu entwickeln, wurden in Modellversuchen zunächst die wichtigsten EinflußGrößen der Verbrennungsreaktion untersucht (wie z. B. Druckverlust in der Katalysatorschüttung oder günstigste Vorwärmtemperatur). Danach wurde ein Nachverbrennungsgerät entworfen, das zwischen 550 und 900°C im mittleren Bereich des Motoren-Kennfeldes den Kohlenmonoxyd-Gehalt der Abgase auf weniger als 0,01 Vol.-% reduziert.
    Additional Material: 9 Ill.
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  • 10
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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