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  • 1
    Electronic Resource
    Electronic Resource
    Ring-opening metathesis polymerization of the bis(methyl carbonate) and bis(S-methyl dithiocarbonate) of norbornene and thermal conversion to poly(cyclopentadienylenevinylene) (1994)
    s.l. : American Chemical Society
    Macromolecules 27 (1994), S. 3769-3772 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma00092a015
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  • 2
    Electronic Resource
    Electronic Resource
    Ruthenium Catalyzed Homocoupling of Terminal Alkynes (1998)
    Springer
    Monatshefte für Chemie 129 (1998), S. 221-233 
    Details
    ISSN: 1434-4475
    Keywords: Keywords. Ruthenium; Poly(acetylene); Conjugated polymers; Dimerization; Trispyrazolylborate.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung.  Die Fähigkeit einiger Komplexe des Typs RuTp(L)(L′)Cl, C–C-Kupplungsreaktion terminaler Alkine zu katalysieren, wurde getestet. Ist L ein Phosphin und L′ ein labiler Ligand, so dimerisieren die Alkine, während sie in Abwesenheit von Phosphinen polymerisieren. RuTp(PPh3)2H ist der beste Katalysator für die Dimerisierung, RuTp(COD)Cl für die Polymerisation. Produktverteilung und Ausbeute sind in erster Linie vom Substituenten am Alkin abhängig, aber auch von den Liganden am Ruthenium. Die katalytisch aktive Spezies ist der 16e−-Alkinyl-Komplex RuTp(L)(–C*C–R), der im Falle von L=PCy 3 und R=Bun als RuTp(PCy 3)(–C*C–Bun)(CO) abgefangen werden konnte.
    Notes: Summary.  Several complexes of the type RuTp(L)(L′)Cl (L, L′=P, N, O donors) were tested with respect to their ability of promoting catalytic C–C-coupling reactions of terminal acetylenes. When L=tertiary phosphine, predominantly dimerization occurs, RuTp(PPh3)2H being the most efficient pre-catalyst. In the absence of a phosphine ligand, polymerization takes place with RuTp(COD)Cl as the most effective pre-catalyst. Both product distribution and conversion depend strongly on the substituent of the alkyne and to a lesser extent on the co-ligands of the ruthenium complex. The catalytically active species is the 16e− alkynyl complex RuTp(L)(–C*C–R) which in case of L=PCy 3 and R=Bu n could be trapped as RuTp(PCy3)(–C*CBu n )(CO).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00010158
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  • 3
    Electronic Resource
    Electronic Resource
    Determination of ethylene-propylene rubber in crosslinked blends with 1,4-polybutadiene (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 155 (1987), S. 143-149 
    Details
    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: Vernetzte Blends aus Ethylen-Propylen-Kautschuk (EPR) und 1,4-Polybutadien (BR) wurden durch Metathese-Abbau der BR-Komponente untersucht; der Prozentsatz des EPR wurde durch Wägen des polymeren Rückstandes bestimmt. Die Metathese-Reaktion wurde mit einem überschuß von 1-Octen in Anwesenheit des Katalysators WCl6/(CH3)4Sn ausgeführt. Bei Vernetzung mit Dicumylperoxid wurden die besten Resultate mit 10 bis 30 Gew.-% EPR und mittleren Vernetzungsgraden erhalten. Die Analyse von Schwefel-Vulkanisaten (erhalten mit dem Beschleuniger N-Cyclohexyl-2-benzothiazylsulfenamid) ergab vertretbare Resultate nur für niedrige Schwefelgehalte (1,5 Gew.-%). EPR konnte auch in unvernetzten Blends mit BR bestimmt werden.
    Notes: Crosslinked blends of ethylene-propylene rubber (EPR) and 1,4-polybutadiene (BR) were investigated by metathesis degradation of the BR component; the percentage of EPR was determined by weighing the polymeric residue. The metathesis reaction was carried out with an excess of 1-octene in the presence of the catalyst WCl6/(CH3)4Sn. In crosslinking with dicumyl peroxide, the best results were obtained with 10 to 30 wt.-% of EPR and medium crosslinking degrees. Analysis of sulphur vulcanizates (received with the accelerator N-cyclohexyl-2-benzothiazyl sulphenamide) gave tolerable results only for low sulphur contents (1.5 wt.-%). Determination of EPR was also possible in non-crosslinked blends with BR.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1987.051550112
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  • 4
    Electronic Resource
    Electronic Resource
    Ring-opening metathesis polymerization of 11-alkylidenebenzonorbornadienes (1994)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 195 (1994), S. 2699-2707 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 11-(α-Phenylbenzylidene)benzonorbornadiene (3) and other similar monomers were synthesized by cycloaddition of dehydrobenzene with different fulvenes. Ring-opening metathesis polymerization of the resulting monomers using Mo-carbene initiators gave highly stereoregular polymers. Variation of the substituents allows control of the stereoregularity of these polymers. Poly[11-(α-phenylbenzylidene)benzonorbornadiene] is completely cis connected, whereas poly[11-(α-methylbenzylidene)benzonorbornadiene] is completely trans linked. The polymers contain two very reactive carbon-hydrogen bonds that are both allylic and benzylic. Elimination of these bridgehead hydrogens gives a fully conjugated polymer that can be described as having “fulvenoid” or “quinoid” geometry.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1994.021950802
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  • 5
    Electronic Resource
    Electronic Resource
    Side chain liquid crystal polymers of 2,3-disubstituted norbornenes via ring-opening metathesis polymerization, 1 influence of flexible spacer length m = 2 to 12 on the thermotropic behaviourDedicated to Prof. emerit. Dr. Josef Schurz, Karl-Franzens-Universität Graz, on the occasion of his 70th birthday (1995)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 196 (1995), S. 3623-3641 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Bis[(4′-cyanobiphenyl-4-yl)oxy-n-alkyl]norborn-5-ene-2,3-dicarboxylates with alkyl chain lengths m = 2 - 12 were synthesized. Most of the monomers exhibit thermodynamically metastable liquid crystalline phases with respect to the crystalline phases. Polymers were prepared by ring-opening metathesis polymerization (ROMP) using the molybdenum carbene initiator [Mo(CH-t-Bu) (NAr) (t-BuO)2] (t-Bu = tert-butyl) with NAr = 2,6-diisopropylaniline. All polymers show thermotropic liquid crystalline phases. Results on characteristic phases and the influence of the number of methylene units m in the flexible spacer on the thermal behaviour (glass transition temperature, isotropization temperature, odd-even effect, enthalpy change) of these new side chain liquid crystal polymers (SCLCP's) are given. They are compared to monosubstituted polynorbornene derivatives and to SCLCP's with other backbones.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1995.021961116
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  • 6
    Electronic Resource
    Electronic Resource
    Detection of C—C cross-links in 1,4-polybutadiene by metathesis degradationPresented at the Macromolecular Symposium, Hamburg, 4-6 October 1982. (1983)
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 4 (1983), S. 429-433 
    Details
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/marc.1983.030040614
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  • 7
    Electronic Resource
    Electronic Resource
    Molecular mechanics calculations on cyclopentenyl compounds, products obtained by olefin metathesis of norbornadiene derivatives (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 6 (1985), S. 302-311 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Molecular mechanics calculations (MM2) are used to elucidate energies and structures of possible reaction products in olefin metathesis of 2,3-dimethylnorbornadiene. The comparison of experimental and calculational results concerning norbornadiene itself shows excellent agreement both in energy and structure. The predicted isomers of lowest energy in a series of three different reaction products seem highly reliable and will lead to a more precise interpretation of the olefin metathesis reaction and the resulting product distribution. Some sixty different isomers have been considered and structures and energies are given. Nonplanarity of double bonds and van der Waals repulsions of closely related hydrogen atoms in polycyclic cycloolefins are considered in some detail. In order to reduce computing time and efforts in obtaining starting coordinates, a computer program for some dimeric structures was devised, which can combine minimized structures stemming from MM2 calculations.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540060407
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  • 8
    Electronic Resource
    Electronic Resource
    Bildung von Cyclopentenylverbindungen beim Metathese-Abbau von modifiziertem 1,4-Polybutadien (1980)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 181 (1980), S. 1847-1860 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This investigation deals with metathesis degradation products of modified 1,4-polybutadiene (poly(1-butenylene)) which have not been taken into consideration as yet, e.g. substituted cyclopentene and linear isomerization products. Substituents were introduced into 1,4-poly-butadiene either by partial bromination with N-bromosuccinimide followed by a Grignard-Wurtz reaction or by reaction with the corresponding methyl compound and dicumyl peroxide. Polymers with 2-methylbenzyl, 4-methylbenzyl, 4-chlorobenzyl, 4-methoxybenzyl, 2-naphthylmethyl, 2,4,6-trimethylphenyl, 1-naphthyl, 9-anthryl, and 9-phenanthryl substituents were degraded by metathesis with 4-octene using WCl6/(CH3)4Sn as a catalyst and were analyzed by gas chromatography/mass spectrometry and by liquid chromatography.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1980.021810907
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  • 9
    Electronic Resource
    Electronic Resource
    Metathesis degradation of partially phenylated 1,4-polybutadiene (1987)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 188 (1987), S. 1795-1808 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 1,4-Polybutadiene was partially phenylated in allyl position by bromination with N-bromosuccinimide and subsequent Grignard-Wurtz reaction with phenylmagnesium bromide. Substitution was to a certain degree coupled with double bond shift. The polymer structure was investigated via metathesis degradation with (E)-4-octene. The degradation products were identified by means of a GC/MS system and determined by GC. Cases of isomerism of products with one phenyl group were investigated. A metathesis product with two phenyl groups in one constitutional unit was found. A distribution function, based on a statistical scission of the macromolecules, was used for evaluations at different metathesis reaction times. Proofs of the reduced reactivity of CC double bonds in the neighbourhood of substituents were received. The yields of the different constitutional units in metathesis products were determined. These were compared with the results of computer simulations in a simplified model. The validity of computer simulations was thereby confirmed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1987.021880803
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  • 10
    Electronic Resource
    Electronic Resource
    Reaktion an Ziegler-Natta-katalysatoren, 11.Mitt. 10: cf.9. Kinetik des metathese-abbaus von teilweise chloriertem polybutadienHerrn Prof. Dr. O. Hromatka (Wien) zum 70. Geburtstag gewidmet (1975)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 176 (1975), S. 1703-1712 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: 1,4-Polybutadiene was partially chlorinated with chlorine in dichloromethane and degradated by olefin metathesis with 4-octene. Low molecular weight substances were analysed by gas chromatography. Products with one isolated chlorinated unit and with two neighbouring chlorinated units of polybutadiene were found. Kinetics of product formation and yields were different for unmodified and chlorinated units.
    Notes: 1,4-Polybutadien wurde mit Chlor in Dichlormethan teilweise chloriert und durch Olefin-Metathese mit 4-Octen abgebaut. Die niedermolekularen Substanzen wurden gaschromatographisch analysiert. Produkte mit einer isolierten chlorierten Einheit und mit zwei benachbarten chlorierten Einheiten des Polybutadiens wurden gefunden. Die Kinetik der Produktbildung und die Ausbeuten waren für unmodifizierte und chlorierte Einheiten unterschiedlich.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1975.021760614
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