ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Polymer and Materials Science  (31)
  • Life and Medical Sciences  (12)
  • Inorganic Chemistry  (10)
  • General Chemistry  (9)
  • Physics
  • 1985-1989  (62)
  • 1970-1974
  • 1985  (62)
Collection
Keywords
Publisher
Years
  • 1985-1989  (62)
  • 1970-1974
Year
  • 1
    Electronic Resource
    Electronic Resource
    Crosslinkable polyamide-imides (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 61-69 
    Details
    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: A series of polyamide-imides were prepared from aromatic diamines and substituted isophthaloyl chlorides containing unsaturated imide rings. Aromatic polyamides from isophthaloyl chloride were also prepared for comparison. The polyamide-imides gave enhanced solubility compared to the aromatic polyamides and there was no deterioration in thermal stability or Tg. The PAIs were crosslinked by heating at 280°C/4 h under nitrogen. After this heat treatment all the PAIs became insoluble and their mechanical properties increased substantially; their thermal behavior, as measured by DSC and TGA, changed as a function of their chemical structure.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1985.070300105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Do parallel β-strands have dipole moments? An ab initio molecular-orbital-direct reaction field study (1985)
    New York : Wiley-Blackwell
    Biopolymers 24 (1985), S. 735-745 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Recently, it was suggested that parallel β-sheets have a significant dipole moment, in contrast to antiparallel sheets. Ab initio molecular-orbital (MO) calculations on parallel and antiparallel β-strands of tetra(Gly) show that they have very similar charge distributions. Interaction energies between two and three strands of tetra(Gly), obtained using the direct reaction field Hamiltonian, show that a particular choice of point charges is probably not crucial for calculating interactions within β-sheets, but that it might be for calculating interactions between these sheets and other parts of a protein, in particular, α-helices. The point-charge representation of our MO-SCF results will probably reduce the hazard of introducing artefacts in electrostatic calculations of protein conformational energies, provided the short-range interactions are treated in a more realistic way, i.e., such that intra- and interchain induction effects are included.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360240502
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Diffusion coefficients of segmentally flexible macromolecules with two sphrical subunits (1985)
    New York : Wiley-Blackwell
    Biopolymers 24 (1985), S. 2145-2164 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The translational and rotational diffusion coefficients have been calculated for a simple, segmentally flexible model: the hinged dumbbell (HD). In the HD, two spherical subunits are attached to an universal joint by means of frictionless connectors. In addition to the case in which hydrodynamic interactions are neglected (NI), we have also considered two more cases, including hydrodynamic interaction by means of the Kirkwood-Riseman approximate treatment (KR) and using accurate procedure based in the series expansions for the two-sphere diffusion tensor (SE). Expressions for the friction coefficients of the HD are given for the three cases, and the diffusion coefficients are evaluted inverting the 9 × 9 resistance matrix, for two HDs with different dimensions. The KR treatment, which includes a contribution from the finite volume of the subunits, is shown to be an excellent approximation to the more rigorous procedure. In the NI case for rotation, the various coefficients present different deviations with respect to the SE results. A rough estimate of the errors of the NI relaxation times indicates that they may be smaller than 15% for a HD with identical beads. However, the influence of hydrodynamic interaction should be more important for the rotational diffusivity of a small sphere attached to a larger one. The error of the NI result for the translational diffusion coefficient is of about 25% for the two HDs.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360241110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Synthesis, Thermolysis, and Photolysis of the Azoalkanes Spiro[4,5-diazatricyclo[4.3.0.03,7]non-4-ene-8,2′-[1.3]dioxolane] and 4,5-Diazatricyclo[4.3.0.03,7]non-4-en-8-one: On the Mechanism of the Oxadi-π-methane Rearrangement of 5-Norbornen-2-one (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3070-3088 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese, Thermolyse und Photolyse der Azoalkane Spiro[4,5-diazatricyclo[4.3.0.03,7]non-4-en-8,2′-[1,3]dioxolan] und 4,5-Diazatricyclo[4.3.0.03,7]non-4-en-8-on. Über den Mechanismus der Oxadi-π-methan-Umlagerung von 5-Norbornen-2-on4,5-Diazatricyclo[4.3.0.03,7]non-4-en-8-on (4) und Spiro[4,5-diazatricyclo[4.3.0.03,7]non-4-en-8,2′-[1,3]dioxolan] (5) wurden ausgehend von Bicyclo[2.2.1]hept-5-en-2-on (1) synthetisiert, indem das entsprechende Urazol 7 durch Cycloaddition von 4-Phenyl-4H-1,2,4-triazol-3,5-dion (PTAD) erhalten wurde. Acetalisierung zum Urazol 9 und anschließende Hydrolyse und Oxidation führten zu den Azoalkanen 4 und 5. Die Regioselektivität der PTAD-Cycloaddition zum Urazol 7 wurde röntgenographisch bewiesen. Direkte und benzophenonsensibilisierte Photolysen des Azoalkans 5 führten zum Tricycloalkan 13, während Thermolyse auch das Pyrazol 12 ergab. Bei der direkten und benzophenonsensibilisierten Photolyse des Azoalkans 4 entstanden Bicyclo[2.2.1]hept-5-en-2-on (1), Tricyclo-[3.2.0.02.7]heptan-3-on (2) und Bicyclo[3.2.0]hept-3-en-6-on (3). Bie der Thermolyse wurden nur die bicyclischen Ketone 1 und 3 erhalten. Es wird postuliert, daß die Photolyse und Thermolyse des Azoalkans 4 primär zu den Diazenyl-Diradikalen 19a, b führt, deren unterschiedliches chemisches Verhalten auf Spinmultiplizität (Singulett- bzw. Triplettzustände) und Elektronenkonfiguration (Dσ,σ- bzw. Dσ,π-Konfiguration) zurückzuführen ist. Die Bildung des Oxadi-π-methan-Diradikals 20 während der Stickstoffabspaltung durch Doppelbruch der C - N-Bindungen entspricht einem untergeordneten Reaktionsweg.
    Notes: 4,5-Diazatricyclo[4.3.0.03,7]non-4-en-8-one (4) and spiro[4,5-diazatricyclo[4.3.0.03,7]non-4-ene-8,2′-[1,3]dioxolane] (5) were prepared starting from bicyclo[2.2.1]hept-5-en-2-one (1) by cycloaddition with 4-phenyl-4H-1,2,4-triazole-3,5-dione (PTAD) to the corresponding urazole 7, followed with acetalization to the urazole 9 and subsequent hydrolysis and oxidation. The regioselectivity of the PTAD-cycloaddition leading to urazole 7 was confirmed by an X-ray analysis. Direct and benzophenone-sensitized photolyses of azoalkane 5 gave the tricycloalkane 13, while in the thermolysis also the pyrazole 12 was formed. Direct and benzophenone-sensitized photolyses of azoalkane 4 yielded bicyclo[2.2.1]hept-5-en-2-one (1), tricyclo[3.2.0.02,7]heptan-3-one (2), and bicyclo[3.2.0]hept-3-en-6-one (3). Thermolysis gave only the bicyclic ketones 1 and 3. It is postulated that the photolysis and thermolysis of azoalkane 4 first lead to diazenyl diradicals 19a, b, which are differentiated in their chemical behavior on account of spin state multiplicities (singlet versus triplet) and electronic configurations (Dσ,σ versus Dσ,π). Formation of the oxadi-π-methane-type 1,3-diradical 20 by denitrogenation involving double C - N cleavage represents a minor product channel.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180807
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Brückenkopf-olefinische Isomere des Triquinacens: Derivate des Tricyclo[5.2.1.04,10]deca-1,5,8- und -1,6,8-triens (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2757-2776 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bridgehead Olefinic Isomers of Triquinacene: Derivatives of Tricyclo[5.2.1.04,10]deca-1,5,8- and -1,6,8-trieneBridgehead halides 12 and 13 of triquinacene (2) with soft nucleophiles undergo a syn-stereoselective SN2′ reaction forming derivatives of tricyclo[5.2.1.04,10]deca-1,5,8-triene 15 and 17, respectively, and of tricyclo[5.2.1.04,10]deca-1,6,8-triene 18. The relative stability of these bridgehead olefins is discussed with regard to force field calculations as well as semiempirical MNDO calculations.
    Notes: Brückenkopf-Mono- 12 und -Dihalogenide 13 des Triquinacens (2) reagieren mit weichen Nucleophilen im Sinne einer syn-stereoselektiven SN2′-Reaktion zu Derivaten des Tricyclo[5.2.1.04,10]-deca-1,5,8-triens 15 bzw. 17 und des Tricyclo[5.2.1.04,10]deca-1,6,8-triens 18. Die relative Stabilität dieser Brückenkopf-Olefine wird anhand von Kraftfeld-Rechnungen sowie semiempirischen MNDO-Rechnungen diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180718
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Metallkomplexe mit biologisch wichtigen Liganden, XXXVII. Peptid-Synthese am Platin (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3135-3142 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metal Complexes with Biologically Important Ligands, XXXVII. Peptide Synthesis at Platinum(II) IonsA series of platinum(II) complexes cis- and trans-Cl2Pt(peptide ester)2 (1 - 16) has been obtained via peptide synthesis at the free carboxylic group of N-coordinated α-amino acids, using a watersoluble carbodiimide as coupling agent. The amino protecting platinum(II) is removed via substitution of the dipeptide ester by 1,2-bis(diphenylphosphino)ethane or, most advantageously, by hydrogenation with hydrogen. Peptide formation and removal of the platinum(II) proceed practically without racemization.
    Notes: Eine Reihe von Platin(II)-Komplexen cis- und trans-Cl2Pt(Peptidester)2 (1 - 16) wird durch Peptid-Synthese an der freien Carboxylgruppe von N-koordinierten α-Aminosäuren mit einem wasserlöslichen Carbodiimid als Kupplungsreagens erhalten. Die Abspaltung der PtII-Aminoschutzgruppe gelingt durch Substitution der Peptidester mit 1,2-Bis(diphenylphosphino)ethan sowie - besonders vorteilhaft - durch Hydrierung mit Wasserstoff. Peptid-Synthese und Abspaltung des Platins(II) verlaufen praktisch racemisierungsfrei.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180812
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Zum Mechanismus der Ozonolyse von C—H-Bindungen: SiO2-Lösungsmitteleinfluß, H/D-Isotopieeffekt, Zwischenstufen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2429-2449 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Mechanism of the Ozonolysis of C — H Bonds: Influence of SiO2-Solvent, H/D Isotope Effect, IntermediatesOzonation of trans-1,2-dimethylcyclohexane (1) in CFCl3 solution, on dry silica gel, and in CFCl3/SiO2 suspension under otherwise equivalent conditions leads to comparable product distributions with very similar rates. In the presence of SiO2 mainly the fraction of retention product is definitely higher. Any activation of substrate or ozone is therefore highly improbable. This is supported by the kinetic H/D isotope effects for [1-D1]trishomobarrelene (10b) and [4,4,8,8-D4]-spiro[2.5]octane (12b), which both in solution and on SiO2 are found to be equal within the error limits. Upon ozonation of trishomobarrelene (10), trishomobullvalene (15), hexahydrobullvalene (7), and norcarane (20) hydrotrioxides occur as detectable intermediates which decompose above -40°C to give alcohols and singlet oxygen. Especially the secondary representatives from 7 and 20 are the first of their kind ever fully characterized by 1H NMR spectroscopy.
    Notes: Die Ozonisierung von trans-1,2-Dimethylcyclohexan (1) in CFCl3-Lösung, auf trockenem Kieselgel und in CFCl3/SiO2-Suspension unter sonst gleichen Bedingungen verläuft mit sehr ähnlichen Geschwindigkeiten zu vergleichbaren Produktspektren. In Gegenwart von SiO2 ist lediglich der Anteil des Retentionsprodukts deutlich höher. Eine Aktivierung von Substrat oder Ozon durch SiO2 ist damit höchst unwahrscheinlich. Dies wird belegt durch die kinetischen H/D-Isotopieeffekte an [1-D1] Trishomobarrelen (10b) und [4,4,8,8-D4]Spiro[2.5]octan (12b), die in Lösung und auf SiO2 innerhalb der Fehlergrenzen jeweils gleich groß gefunden wurden. Bei der Ozonisierung von Trishomobarrelen (10), Trishomobullvalen (15), Hexahydrobullvalen (7) und Norcaran (20) treten Hydrotrioxide als nachweisbare Zwischenstufen auf, die oberhalb -40°C zu Alkoholen und Singulettsauerstoff zerfallen. Insbesondere die sekundären Vertreter aus 7 und 20 sind die ersten ihrer Art, die 1H-NMR-spektroskopisch eindeutig charakterisiert werden konnten.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180622
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Bequeme Synthese von Vinylcyclopropanen durch intermolekularen Abfang von thermisch erzeugtem Perchlorvinylcarben (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2450-2471 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Convenient Synthesis of Vinylcyclopropanes by Intermolecular Trapping of Thermally Generated PerchlorovinylcarbeneTetrachlorocyclopropene (1) is ringopened above 150°C to give perchlorovinylcarbene (2), which is intermolecularly trapped by olefins with high efficiency. The olefin configuration is retained in the products, 1-chloro-1-(trichlorovinyl)cyclopropanes 7, 11, and 14, respectively. With n-hexane and adamantane 17 - 19 as well as 21 and 22 are obtained by C — H insertion. For 21 olefins with different degrees of substitution and types of substituents the isolated yields range from 24 to 88%, in most cases above 60%. Acrylonitrile (9%) and substituted acrylonitriles (17%) give lower yields, acrylates, however, react well. The torsional barriers of the chloro(trichlorovinyl)cyclopropane derivates 14 are unusually high (17.4 - 18.6 kcal/mol) for vinylcyclopropane systems. Products 7 can be reductively dechlorinated to vinylcyclopropane hydrocarbons 23, ethylidene-cyclopropanes 24 being observed as by-products.
    Notes: Tetrachlorcyclopropen (1) wird oberhalb 150°C ringgeöffnet zu Perchlorvinylcarben (2), welches sich mit hoher Effizienz intermolekular an Olefine addiert. In den Produkten, 1-Chlor-1-(trichlorvinyl)cyclopropanen 7, 11 bzw. 14, bleibt die Olefinkonfiguration erhalten. Mit n-Hexan und Adamantan entstehen durch C — H-Insertion 17 - 19 sowie 21 und 22. Mit 21 Olefinen verschiedenen Substitutionsgrades und Typs liegen die isolierten Ausbeuten zwischen 24 und 88%, in den meisten Fällen oberhalb 60%. Acrylonitril (9%) und substituierte Acrylonitrile (17%) geben schlechtere Ausbeuten, Acrylsäureester dagegen normale. Die Torsionsbarrieren der Chlor(trichlorvinyl)cyclopropan-Derivate 14 sind mit 17.4 - 18.6 kcal/mol für Vinylcyclopropane ungewöhnlich hoch. Die Produkte 7 können reduktiv vollständig zu den entsprechenden Vinylcyclopropan-Kohlenwasserstoffen 23 dehalogeniert werden, wobei Ethylidencylopropane 24 als Nebenprodukte auftreten.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180623
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Epoxidation des Barrelens: Darstellung und Eigenschaften von Oxahomobarrelenen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3993-4005 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Epoxidation of Barrelene: Preparation and Properties of OxahomobarrelenesA four-step synthesis makes barrelene (1) readily accessible on a 1 - 2 g scale. Upon epoxidation with KHCO3-buffered m-chloroperbenzoic acid 1 yields the mono- (2b), both the endo,exo- and exo,exo-isomeric bis- (3b and 4b) as well as the trisepoxide 5b. In the presence of traces of acid 2b very rapidly rearranges to cycloheptatriene-7-carbaldehyde (15), 5b undergoes a facile acid-catalyzed rearrangement to 4,7,11-trioxatrishomocubane (16). Under basic and neutral conditions 5b is stable towards virtually any nucleophile, its three epoxide rings can only be opened under reductive conditions with solvated electrons. On the other hand, endo,exo-dioxadihydrobishomobarrelene 20 and oxatrishomobarrelene 23 are readily attacked at the oxirane rings by lithium iodide/disodium hydrogen phosphate.
    Notes: In einer nur vierstufigen Synthese ist Barrelen (1) im Maßstab von 1 - 2 g rasch zugänglich. Bei der Epoxidation von 1 mit KHCO3-gepufferter m-Chlorperbenzoesäure werden das Mono- (2b), die endo,exo- und exo,exo-Isomeren Bis- (3b bzw. 4b) sowie das Trisepoxid 5b erhalten. In Gegenwart von Säurespuren lagert sich 2b sehr leicht in Cycloheptatrien-7-carbaldehyd (15), 5b leicht in 4,7,11-Trioxatrishomocuban (16) um. Unter basischen und neutralen Bedingungen ist 5b gegen alle möglichen Nucleophile stabil, lediglich durch Reduktion mit solvatisierten Elektronen lassen sich alle drei Epoxidringe öffnen. endo,exo- Dioxadihydrobishomobarrelen 20 und Oxatrishomobarrelen 23 werden dagegen von Lithiumiodid/Dinatriumhydrogenphosphat an den Oxiranringen glatt angegriffen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851181012
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Equilibrium copolymerization, 1. Random model (1985)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 186 (1985), S. 597-608 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Three cases of equilibrium copolymerization are re-treated theoretically. The expression of the molecular weight distribution of the copolymer is a two-dimensional distribution function with two random variables m and n, where m and n are the numbers of two different monomeric units, respectively. The molecular parameters of the copolymer, such as the number- and weight-average molecular weights, number-average degree of polymerization, copolymer composition and equilibrium conversions of comonomers, are derived. The relation between the parametric variables in the formulae and the equilibrium copolymerization conditions are determined from two binary cubic equations.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1985.021860314
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...