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
  • Chemistry  (456)
  • Physics  (41)
  • AUXILIARY SYSTEMS  (12)
  • 1975-1979  (235)
  • 1970-1974  (170)
  • 1965-1969  (104)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    The radical initiation of vinyl polymerization by α.α.α′.α′-Tetrasubstituted dibenzyls (1972)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 157 (1972), S. 279-298 
    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: Im Temperaturbereich von 60 bis 100°C wird die radikalische Polymerisation von Styrol, Methylmethacrylat und Acrylnitril von α.α′-Dicyanodibenzylen ausgelöst, die in α-und α′-Stellung mit Ester-, Nitril-, Amid- oder Phenylgruppen disubstituiert sind. Bei 100 bis 110°C ist auch das α.α.α′.α′-Tetracarboxymethyldibenzyl aktiv. Vinylacetat und Vinylchlorid werden durch diese Initiatoren kaum polymerisiert.Fur die Polymerisation des Styrols wurden die Bruttogeschwindigkeitskonstanten Kp, für viele Dibenzyle und fur Peroxide vergleichbarer Aktivitat dilatornetrisch bestirnrnt. Norrnalerweise sind die Zeit-Urnsatz-Kurven rnit den Dibenzylen und den Peroxiden vergleichbar; das Tetracyanodibenzyl allerdings bewirkt nur eine unvollstandige Polymerisation.Der große Einfiuß von Substituenten in α-Stellung oder in den Phenylringen der Dibenzyle auf die Polymerisation des Styrols wird diskutiert. Dabei ist auch die Stereochernie wichtig. Die meso-Form des Dinitrildiesters ergibt eine 2.5- bis 3.5 ma1 schnellere Polyrnerisation als das dl-Isornere.Die Dissoziationsgeschwindigkeitskonstanten kd der Initiatoren wurden NMR-spektroskopisch aus der Linienbreite bestirnmt. Die Dinitrildiester sind gute Initiatoren, wahrend die α.α′-Dicyanodibenzyle rnit weiteren Nitril- oder Phenylgruppen in α- und α′-Stellung wenig geeignet sind. SchlieBlich wurde die 1.2-Addition einiger der Dibenzyle an Styrol im Ternperaturbereich von 120 bis 150°C rnit der Methode der chernisch induzierten KernPolarisation (CIDNP) untersucht.
    Notes: The radical polymerization of styrene, methyl methacrylate and acrylonitrile is initiated by α.α′-dicyanodibenzyls α.α′-disubstituted with ester, nitrile, amide or phenyl groups in the temperature range 60 to 100°C and by α.α.α′.α′-tetracarboxymethyldibenzyl at 100 to 110°C. Vinylacetate and vinylchloride show a low reactivity.The overall polymerization rate constants Kp have been determined dilatometrically for styrene initiated by a large number of dibenzyls and comparable peroxides. The styrene polymerization curves are generally comparable with those of peroxides. A notable exception is tetracyanodibenzyl.The strong influence of α- and ring-substituents in the dibenzyls on the styrene polymerization rate is discussed. The stereochemistry is also important : the meso α.α′-dicyanodibenzyls α.α′-disubstituted with ester groups give a 2.5 to 3.5 fold faster polymerization than their dl isomers.The initiator efficiency is related to the kd values, determined from NMR line width measurements. The α.α′- dicyanodibenzyls α.α′-disubstituted with ester groups are good initiators, while those with phenyl groups and nitrile groups are inefficient.Relevant to initiation and termination, the 1.2-addition of some of the dimers to styrene at 120 to 150°C has been studied with chemically induced dynamic nuclear polarization (CIDNP).
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1972.021570128
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    New structures of LD-alternating polypeptides in solution and in the solid state (1975)
    New York : Wiley-Blackwell
    Biopolymers 14 (1975), S. 1109-1114 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1975.360140518
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and viscosity behavior of poly(γ-p-biphenylmethyl-L-glutamate) in benzene/dichloroacetic acid mixtures, a comparison with poly(γ-benzyl-L-glutamate) (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 3193-3206 
    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: Die Darstellung von Poly(γ-p-biphenylmethyl-L-Glutamat), PBPLG, (Poly{L-imino-1-[2-(4-biphenylmethoxycarbonyl)äthyl]-2-oxoäthylen}), (1d) wird beschrieben. Das Viskositätsverhalten dieses Polymers in Mischungen aus Benzol und Dichloressigsäure (c=0,2.10 - 3 - 1,4.10 - 3g/cm3) bei 25°CC wird untersucht. Die Ergebnisse werden verglichen mit Messungen unter den gleichen Bedingungen an Poly(γ-benzyl-L-Glutamat),PBLG, (Poly[ L-imino-l-(2-benzyloxycarbonylathyl)-2-oxoathylen]), (lc). In beiden Fallenfindet ein zweistufiger Ubergang von einer starren, von Wasserstoffbrucken stabilisiertenHelix in ein statistisches, solvatisiertes Knduel statt : PBPLG (erste Stufe CrSSX,, zweite Stufe 55-100%, Dichloressigsaure und PBLG (erste Stufe 0-70%, zweite Stufe 70-100%,Dichloressigsaure)).Die Einfiihrung eines p-Phenylsubstituenten in PBLG fuhrt deshalb in Mischungen aus Benzol- und Dichloressigsaure zu einer weniger stabilisierten Helix.Die Stabilitat und das Viskositatsverhalten von PBLG in Mischungen aus Benzol und Dichloressigsaure (c=0,2.10-3 -14.10-3g/cm3) sind denjenigen von PBLG in Mi-schungen aus m-Kresol und Dichloressigslure ( c = 1,0.10-3-4,0. 10-3g/cm3) ähnlich.
    Notes: The synthesis of poly(γ-p-biphenylmethyl-L-glutamate), PBPLG, (poly{L-imino-1-[2-(4-biphenylylmethoxycarbonyl)ethyl]-2-oxoethylene}), (1d) is described. The viscosity behavior of this polymer in benzene/dichloroacetic acid mixtures (c=0,2.10 - 3 - 1,4.10 - 3 g/cm3) at 25°CC is investigated. The results are compared with measurements on poly(γ-benzyl-L-glutamate), PBLG, (poly[L-imino-1-(2-benzyloxycarbonylethyl)-2-oxoethylene]), (1c) under the same conditions. A transition from a rigid hydrogen bonded helix to a random solvated coil occurs in two stages for both: PBPLG (first stage 0 - 55%, second stage 55 - 100% dichloroacetic acid) and PBLG (first stage 0 - 70%, second stage 70 - 100% dichloroacetic acid).Therefore, the introduction of a p-phenyl substituent in PBLG leads to a less stable helix in benzene/dichloroacetic acid mixtures.The stability and viscosity behavior of PBLG in benzene/dichloroacetic acid mixtures (c=0,2.10 - 3 - 1,4.10 - 3g/cm3) is quite similar to the behavior of PBLG in m-cresol/dichloroacetic acid mixtures (c=1,0.10 - 3 - 4,0.10 - 3 g/cm3).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021751113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Fungal cultures and culture mediums for the production of cellulase (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1123-1129 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Cellulase production by strains of Myrothecium verrucaria, Stachybotrys atra and Trichoderma viride was examined. Myrothecium verrucaria was found to give the greatest yields. A variety of media were examined as potential substrates for the industrial production of cellulase. The salts content of the medium was varied and was found to affect cellulase production. Glucose, carboxymethylcellulose (CMC), filter paper and three industrial wastes were examined as possible cellulase inducers. Filter paper was found to be the most effective, followed by sugar cane bagasse and CMC.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260150610
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A semicontinuous experimental technique for the study of the influence of mixing conditions on the homogeneity of sewage sludge (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 19 (1977), S. 1087-1090 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260190709
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Poly(γ-p-nitrobenzyl-L-glulainate): synthetic aspects, sedimentation, and viscosity studies (1971)
    New York : Wiley-Blackwell
    Biopolymers 10 (1971), S. 2509-2523 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of poly(γ-p-nitrobenzyl-L-glutamates), PNBG, has been synthesized by the polymerization of N-carboxyanhydride (NCA) derivatives of γ-p-nitrobenzyl-L-glutamate, NBG, using triethylamine as an initiator. We studied the influence of (a) the solvents dioxane, nitrobenzene, dimethylformamide (DMF), and DMF-1,2-dichloroethane mixture and (b) the anhydride-initiator ratio (A/I) for the polymerization in nitrobenzene (A/I varying from 50 to 750) on the properties of the polymers obtained. In order to improve its synthesis, NBG, was prepared by three different methods. Ten samples of PNBG, ranging in Mw from 10,000 to 50,000, were examined viscometrically in DMF and dichloroacetic acid (DCA) and by ultracentrifugation in DMF. The data for [η] and So (limiting sedimentation coefficient) as functions of Mw for PNBG in DMF were utilized, applying theories of Kuhn and Kuhn,13 Schachman,14 and Perrin, 15 for the estimation of the length per monomeric residue h. Viscosity data gave a h value of about 2.3 Å, Whereas sedimentation yielded 1.5 Å. Treating viscosity and sedimentation data for poly(γ-benzyl-L-glutamate), PBLG, in the same way leads to somewhat higher hvalues (2.4 Å and 1.7 Å, respectively).Although a nitroaromatic effect was shown to be absent for PNBG in DMF, it can be concluded that in this medium PNBG has a somewhat more compact structure than PBLG.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360101212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Modern methods for the analysis of urea formaldehyde resins (1976)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 54 (1976), S. 187-201 
    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: Moderne instrumentelle Methoden wurden zur Analyse von Harnstoff-Formaldehyd-Harzen verwendet. Ein ausführliches Studium der Silylierung des Harzes mittels BSTFA (N,O-Bistrimethylsilyltrifluoracetamid) ermöglicht die quantitative gaschromatographische Bestimmung der niedermolekularen Verbindungen Harnstoff, Monomethylolharnstoff und Dimethylolharnstoff. Das Verhältnis zwischen nieder- und hochmolekularen Verbindungen sowie die Mengen an niedermolekularen Verbindungen können mittels GPC-Analyse auf Sephadex LH 20 in Wasser ermittelt werden.Ein vollständiges Bild des Harzes erhält man durch 220 MHz 1H-NMR-Analyse von Lösungen von gefriergetrockneten Proben in DMSO-d6. Zusammen mit den Ergebnissen klassischer chemischer Analysen ergeben die Resultate der drei genannten Techniken einen guten Überblick über den Aufbau eines Harnstoff-Formaldehyd-Harzes.
    Notes: Modern instrumental techniques were used for analysing water-based urea-formaldehyde resins. An exhaustive study was made of the silylation of such a resin with BSTFA (N,O-bistrimethylsilyltrifluoroacetamide). From the gas chromatograms the amounts of urea, monomethylol urea and dimethylol urea can be determined quantitatively, thus giving information on the low molecular weight part of the resin. The ratio of low to high molecular weight components as well as the amounts of several low molecular weight compounds can be estimated from a GPC analysis on Sephadex LH 20 in water. A detailed picture of the resin is obtained when freeze-dried samples are subjected to 220 MHz 1H-NMR analysis in DMSO-d6.An overall insight into the composition of these resins can be gained when the results of the mentioned techniques are combined with those of classical chemical analyses.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1976.050540114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    13C-NMR analysis of formaldehyde resins (1977)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 62 (1977), S. 7-31 
    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: Die 13C-NMR-Spektroskopie wurde zur Analyse von Formaldehyd-Harzen verwendet. Aus Phenolen, Harnstoff und Melamin wurden mit Formalin Harze hergestellt. Die chemischen Verschiebungen dieser Harze wurden relativ zu TMS gemessen. Alle Harze waren in DMSO-d6 löslich, so daß die Signale von unterschiedlichen Harzen verglichen werden konnten.Die Spektren wurden mit Hilfe der Spektren von Referenzsubstanzen und einfachen, auf Additivität basierenden Rechenregeln interpretiert. Jeder Harztyp hat sein eigenes spezifisches Spektrum und enthält Signale, die über die Struktur im Zusammenhang mit dem Katalysatortyp und der Kondensationsweise Auskunft erteilen. Die unterschiedlichen Formen, in denen Formaldehyd in diese Harze als Methylenkohlenstoff eingebaut ist, lassen sich unzweideutig aus dem Gebiet von 20 bis 100 ppm bestimmen.Diese Arbeit zeigt, daß sich die 13C-NMR Spektroskopie sehr gut für die Analyse von Formaldehydharzen eignet.
    Notes: 13C-NMR spectroscopy has been applied to the analysis of formaldehyde containing resins. Samples have been prepared from phenols, urea and melamine with formaldehyde. The chemical shifts of the carbon atoms in the resins were measured relative to TMS. All the samples could be dissolved in DMSO-d6 which facilitated the comparison of signals in different resins.The spectra were interpreted with the aid of spectra of reference compounds and simple calculations based on additivity increments. Each type of resin gives a specific 13C-NMR spectrum in which lines can be assigned that give information on the structure of the resin in relation to the type of condensation or catalyst used. Moreover, the different ways in which formaldehyde is incorporated in the resins as methylene carbon can be unambiguously determined from the region between 20 and 100 ppm.This work shows that 13C-NMR spectroscopy is a powerful tool for the analysis of formaldehyde containing resins.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1977.050620102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Electron impact mass spectral studies of hydrazine monoamine oxidase inhibitor drugs (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 82-89 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Identification of hydrazine monoamine oxidase inhibitor drugs such as isoniazid, iproniazid, nialamide, isocarboxazid and iproclozide is made by electron impact mass spectrometry using the direct insertion technique. The molecular ion itself, although of low relative abundance, is found in the mass spectra of all compounds studied. Relative intensities of the major fragments and data on metastable ions useful in the identification of these compounds are reported. With the aid of synthesized structurally related products, deuterium labelling of exchangeable hydrazidic and hydrazinic protons and by the use of hexadeuterated isopropylic analogues, detailed information about fragmentation patterns is obtained. Splitting processes are chiefly governed by the nature of the aromatic substituent at the hydrazidic end and the alkyl sidechain located at the second hydrazinic nitrogen. The major fragmentations occurring are loss of small neutral molecules, double rearrangement, cleavage of the N—N bond, amide bond rupture, β-cleavage to the hydrazinic nitrogen atom and McLafferty rearrangements.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200020204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The Stabilization Energy of [18] Annulene. A thermochemical determination (1974)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 57 (1974), S. 2276-2288 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal rearrangement of [18]annulene in solution gives benzene and 1,2-benzo-1,3,7-cyclooctatriene. This reaction has been investigated using a differential scanning calorimeter and the associated enthalpy change has been measured. The enthalpy of the reaction (in the gase phase at 298°K) is \documentclass{article}\pagestyle{empty}\begin{document}$$ \Delta {\rm H}_{\rm r} \left({{\rm g},\,298^ \circ } \right) = - 50.7 \pm 5\,{\rm kcal mol}^{{\rm - 1}} $$\end{document} From this value and the enthalpies of formation of the reaction products, the enthalpy of formation of [18]annulene is obtained: \documentclass{article}\pagestyle{empty}\begin{document}$$ \Delta {\rm H}_{\rm f} \,^ \circ \left({{\rm 1,}\,{\rm g},\,298^ \circ } \right) = 124 \pm 5.5\,{\rm kcal mol}^{{\rm - 1}} $$\end{document} The stabilization energy of [18]annulene, defined as the difference between the enthalpy of formation of the hypothetical Kékulé [18]annulene (with single and double bonds of normal lengths) and the heat of formation of the real molecule is then \documentclass{article}\pagestyle{empty}\begin{document}$$ \Delta {\rm H}_{{\rm stab}{\rm .}} \left({\rm 1} \right) = 37 \pm 6\,{\rm kcal mol}^{{\rm - 1}} $$\end{document} a value close to the corresponding quantity found for benzene.The very large stabilization energy of [18]annulen (100 ± 6 kcal mol-1) previously reported in the literature, based on measurements of the heat of combustion, is not correct since the annulene is certainly oxidized in the bomb prior to combustion.The isodynamic conformational mobility of [18]annulene is not incompatible with a stabilization energy of 37 kcal mol-1; the activation enthalpy observed for this process (ΔH≠ = 16.1 kcal mol-1) indicates that the stabilization is not completely destroyed in the transition state.The mechanism of the thermolysis of [18]annulen, investigated by kinetic measurements and by analysis of the shape of the thermograms, is discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19740570745
    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...