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  • 1
    Electronic Resource
    Electronic Resource
    Über die Natur der „roten” K-Lösungen in Benzol in Gegenwart von Polyäthylenoxid (1977)
    Springer
    Colloid & polymer science 255 (1977), S. 720-720 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01550181
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  • 2
    Electronic Resource
    Electronic Resource
    Lösungen von Alkalimetallen in Äthern in Anwesenheit von hexamethylphosphorsäuretriamid (1972)
    Springer
    Monatshefte für Chemie 103 (1972), S. 1119-1129 
    Details
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Lösungen von Lithium, Natrium und Kalium in Tetrahydrofuran (THF) in Anwesenheit von Hexamethylphosphorsäuretriamid (HMPA) weisen einen schwachen Paramagnetismus auf (Konzentration der paramagnetischen Teilchen 10−6 Mol/l). Die EPR-Spektren der Lithium- und Natrium-lösungen haben keine Ultrafeinstruktur (von 20 bis −180°C), dagegen weisen jene von Kalium bei Temperaturen unter −50°C fünf charakteristische Linien auf. Dieses EPR-Spektrum ist mit dem der “blauen” Kaliumlösung inTHF in Anwesenheit von Polyäthylenoxyd (die von den Autoren bereits früher untersucht wurden) identisch. Die Metallösungen inTHF-HMPA übertragen an Hexamethylaceton, Benzol und Biphenyl ein Elektron, wobei Anion-Radikale dieser Verbindungen gebildet werden. Es findet auch ein Übergang von K− zu Na statt. Die Spektren der untersuchten Lösungen im Sichtbaren und im IR enthalten charakteristische Maxima für “blaue” Metallösungen in Aminen und Äthern. Die Konzentration an leitfähigen Teilchen ist größer als die an paramagnetischen. Die Lösungen sind aktive Starter der anionischen Polymerisation. Die Versuche zeigen, daß die Lösungen der Alkali-Metalle inTHF-HMPA keine Anion-Radikallösungen vonHMPA sind.
    Notes: Abstract The properties of solutions of Li, Na and K in tetrahydrofurane (THF) in the presence of hexamethyl phosphoric triamide (HMPA) were investigated. The solutions possess a slight paramagnetism (concentration of paramagnetic particles 10−6 mole/l). The ESR-spectra of solutions of Na have not a hyperfine structure (temperatures range +20 to −180°C) while those of K at temperatures lower than −50°C have five characteristic lines. That ESR-spectrum is similar to the spectrum of a “blue” solution of K inTHF in the presence of polyethylene oxide, investigated earlier by the present authors. An electron transfer of metal solutions inTHF-HMPA to hexamethylacetone, benzene and biphenyl was observed with formation of anion-radicals of the latter. A transfer from K− to Na is realized too. The visible and I.R. spectra of the investigated solutions showed the characteristic maximum for the “blue” solutions of metals in amines and ethers. The concentration of electroconducting particles is larger than that of paramagnetic ones. The solutions are efficient initiators of anionic polymerization. The results obtained indicate that the solutions of alkali metals inTHF-HMPA are not solutions of theHMPA anion-radical.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00905188
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  • 3
    Electronic Resource
    Electronic Resource
    Hydride transfer to stable carbenium salts (1983)
    Springer
    Polymer bulletin 10 (1983), S. 411-413 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The interaction between (C6H5)3CSbCl6, (C6H5)2CHSbCl6, (ClC6H4)3CSbCl6 and poly(ɛ-caprolactone), dimers of α-methyl-styrene and of 1,1-diphenylethylene is investigated. By the use of 1H-NMR spectroscopy it is found that hydride transfer proceeds to the stable salts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00262182
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  • 4
    Electronic Resource
    Electronic Resource
    Über die Reduktionsformen einiger nichtenolisierenden aromatischer Ketone und Chinone, welche die Vinylpolymerisation zu initiieren vermögen (1970)
    Springer
    Monatshefte für Chemie 101 (1970), S. 1797-1805 
    Details
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract It is known that the reduction forms of aromatic carbonyl compounds (ACC) initiate anionic polymerization of vinyl monomers. The ability of the reduction forms to transfer an electron to the interacting molecules is defined also by the electron affinity of the partners. To obtain data about the electron affinity the half-wave potentials of polarographic reduction were measured and compared with the values of the lowest antibonding molecular orbital, according to theHückel's method. A linear correlation between the potentials of polarographic reduction and the energy of the lowest antibonding molecular orbit was found. The results prove the correctness of the previously determined electroaffinity defined by electron transfers between the reduction forms and neutral molecules. From the data of quantum chemical calculation and the polarographic reduction ofACC the changes of the free energy, enthalpy and the equilibrum constant for electron transfer reaction were calculated. The initiation ability of the reduction forms ofACC and the elctron affinity discussed.
    Notes: Zusammenfassung Bekanntlich lösen die Reduktionsformen aromatischer Carbonylverbindungen (ACV) eine anionische Polymerisation von Vinylmonomeren aus. Das Vermögen der Reduktionsformen vonACV, den mit ihnen in Wechselwirkung tretenden Molekülen ein Elektron zu übertragen, wird von der Elektronenaffinität beider Partner bestimmt. Um Angaben bezüglich der Elektronenaffinität zu ermitteln, wurden die Potentiale der polarographischen Reduktion gemessen und mit den nach derHückel-Methode berechneten Energiewerten des niedrigsten antibindenden Molekülorbitals korreliert. Für eine Reihe strukturell verwandter Verbindungen wurde eine lineare Abhängigkeit zwischen den Halbstufenpotentialen der polarographischen Reduktion und des niedrigsten antibindenden Molekülorbitals gefunden. Die so erhaltene Reihe stimmt mit einer bereits früher aufgestellten überein. Auf Grund quantenmechanischer Berechnungen und der gemessenen polarographischen Halbstufenpotentiale derACV wurden die Änderungen der Freien Enthalpie, die Enthalpie-Änderung und die Gleichgewichtskonstante des Überganges eines Elektrons von der Reduktionsform zum Monomeren ermittelt. Ferner wurde der Zusammenhang zwischen Initiierungsvermögen der Reduktionsformen vonACV und der Elektronenaffinität diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01152094
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  • 5
    Electronic Resource
    Electronic Resource
    Polymerisation von Methacrylaldehyd und Crotonaldehyd mit verschiedenen Initiatoren vom Anion-Radikal-Typ (1975)
    Springer
    Colloid & polymer science 253 (1975), S. 338-338 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02352130
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  • 6
    Electronic Resource
    Electronic Resource
    Kinetik der Styrolpolymerisation mit BF3.(C2H5)20 in Gegenwart von π-Elektronen-Acceptoren (1977)
    Springer
    Colloid & polymer science 255 (1977), S. 809-809 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01664467
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  • 7
    Electronic Resource
    Electronic Resource
    Wechselwirkung zwischen Polyäthylenoxid und Fluorenyl-Alkalimetall-Verbindungen in Tetrahydrofuran (1978)
    Springer
    Colloid & polymer science 256 (1978), S. 192-193 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01679342
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  • 8
    Electronic Resource
    Electronic Resource
    Darstellung von isotaktischem Polystyrol auf binären K- Graphit-Inklusions-Verbindungen (1976)
    Springer
    Colloid & polymer science 254 (1976), S. 945-945 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01775556
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  • 9
    Electronic Resource
    Electronic Resource
    Elektronen-Absorptionsspektren der Anion-Radikale und Dianionen von aromatischen Nitrilen (1970)
    Springer
    Monatshefte für Chemie 101 (1970), S. 1672-1685 
    Details
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Electronic absorption spectra ofAR andDA of aromatic nitriles obtained by reduction with alkali metals and Mg in ether-type solvents (THF, DME, DO, ether etc.) were studied. A correlation was established between the longest wavelength transition energies determined both byHückel's method (LCAO—MO) and experimentally inDME (counter-ion K). The influence of the counter-ion, solvent and concentration on the spectra was studied. On the basis of the results as well as from the check-up of theBeer's law it was established that theAR of aromatic nitriles inDME andTHF (counter-ion K) exist as solvent separated ion pairs while inDO and ether ion associates are present. In benzene the diamagnetic dimer was formed.
    Notes: Zusammenfassung Es wurden die Elektronen-Absorptionsspektren der Anion-Radikale (AR) und Dianionen (DA) von aromatischen Nitrilen, erhalten durch Reduktion mit Alkalimetallen und Mg in Lösungsmitteln vom Äthertyp (THF, DMÄ, DO, Äther u. a.)* aufgenommen. Eine Korrelation zwischen den nach der einfachenHückelschen Methode bestimmten (fürAR) und den experimentell inDMÄ (Gegenion K) erhaltenen Energien der längstwelligen Übergänge wurde festgestellt. Es wurden der Einfluß des Gegenions, der Natur des Lösungsmittels und der Konzentration auf die Spektrenart untersucht. Aus den erhaltenen Angaben sowie aus der Überprüfung desLambert-Beerschen Gesetzes wird geschlossen, daßAR der aromatischen Nitrile inDMÄ undTHF (Gegenion K) als durch Lösungsmittelmoleküle getrennte Ionenpaare vorliegen, dagegen inDO und Äther als Assoziate. In Benzol bildet sich ein diamagnetisches Dimeres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01152081
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  • 10
    Electronic Resource
    Electronic Resource
    Interactions of ligands with lithium picrate in dioxane (1990)
    Springer
    Journal of solution chemistry 19 (1990), S. 425-436 
    Details
    ISSN: 1572-8927
    Keywords: Complexation ; lithium picrate ; competition method ; dioxane ; ion binding ligands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The interaction of several cyclic ethers, poly(ethylene glycol dimethyl ether)s, nitriles, esters and ketones with lithium picrate in dioxane at 25°C was investigated by means of a competition method using cross-linked poly(ethylene oxide) (PEO) as the insoluble ligand. The Langmuir-Klotz isotherm of LiPi binding to the PEO gel gave an apparent binding constant, K′, as a function of the concentration of added ligand. Plots of 1/K′ vs. the ligand concentration then yielded the formation constant, K L , of the ligand complex with LiPi. The results demonstrate that in dioxane one ligand molecule binds to LiPi. While there is some dependence on the Gutmann donicity number of the respective ligands, steric factors often play a dominant role in determining the value of K L . The results were compared with complexation data obtained on similar systems but by different methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00650375
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