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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of sol gel science and technology 8 (1997), S. 507-509 
    ISSN: 1573-4846
    Keywords: silica films ; chemical modification ; IR ; MAS NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The sol-gel technique has been used for the preparation of silica films. The properties of these layers were varied by modification with aliphatic and aromatic compounds containing carbonyl groups. Structural changes in the gels were observed by IR and MAS NMR spectroscopy. The incorporated organic compounds interact weakly with the gel matrix, forming hydrogen bridges.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of sol gel science and technology 8 (1997), S. 507-509 
    ISSN: 1573-4846
    Keywords: silica films ; chemical modification ; IR ; MAS NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The sol-gel technique has been used for the preparation of silica films. The properties of these layers were varied by modification with aliphatic and aromatic compounds containing carbonyl groups. Structural changes in the gels were observed by IR and MAS NMR spectroscopy. The incorporated organic compounds interact weakly with the gel matrix, forming hydrogen bridges.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Basic Aluminium Salts and their Solutions. VII. Influence of Preparation, Concentration, and Aging on the Constitution of Solutions of Basic Aluminium Salts0.1 to 4 molar basic aluminium chloride solutions - prepared by dissolving aluminium metal in substoichiometric quantities of hydrochloric acid and 10-4 to 0.2 molar basic solutions of aluminium chloride and perchlorate - prepared by adding alkali to the solutions of the neutral salts were investigated for the kinetics of their reactions with ferrone and by 27Al NMR spectroscopy. In all solutions the contents of polymeric species decreases at equal basicity with increasing aluminium concentration. On the other hand the Al13O40 complex is only formed in solutions prepared by addition of alkali. The differences of composition are confirmed by the aging behaviour of the solutions.
    Notes: 0,1 bis 4 molare basische Aluminiumchloridlösungen - hergestellt durch Auflösen von metallischem Aluminium in unterstöchiometrischen Mengen an Salzsäure und 10-4 bis 0,2 molare basische Lösungen von Aluminiumchlorid und -perchlorat - hergestellt durch Zugabe von Lauge zu den Lösungen der neutralen Salze werden in ihrem kinetischen Verhalten gegen Ferron und durch 27Al-Kernresonanz-Messungen untersucht. In allen Lösungen nimmt der Anteil an polymeren Teilchen bei gleichem Basizitätsgrad mit steigender Aluminiumkonzentration ab. Dagegen bildet sich nur in den durch Zugabe von Lauge hergestellten Lösungen der Al13O40-Komplex. Die unterschiedliche Zusammensetzung der Lösungen gibt sich auch in ihrem Alterungsverhalten zu erkennen.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 503 (1983), S. 37-42 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Properties of Compounds with Heteropolycations. I. Dodecaaluminogermaniumsulfate [GeO4Al12(OH)24(H2O)12](SO4)4 · xH2OBy reaction of aqueous solutions of aluminum chloride and sodium germanate and subsequent precipitation as sulfate a cristalline product is obtained, which is the title compound according to chemical analysis and 27Al-NMR in analogy to the wellknown tridecameric basic aluminum cation. From thermal analysis and kinetic measurements is concluded that the title compound has a higher stability than the tridecameric basic aluminum cation.
    Notes: Durch Umsetzung wäßriger Aluminiumchlorid- und Natriumgermanatlösung und nachfolgende Fällung als Sulfat wird ein kristallines Produkt erhalten, das nach den Ergebnissen der chemischen Analyse und von 27Al-Kernresonanzmessungen in Analogie zum bekannten tridekameren basischen Aluminiumkation als die im Titel angegebene Verbindung mit einem Heteropolykation angesehen werden kann. Aus thermoanalytischen und kinetischen Messungen wird geschlossen, daß die Verbindung eine größere Stabilität als das tridekamere basische Aluminiumsulfat besitzt.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Basic Aluminum Salts and their Solutions. XVI. Kinetic Studies on Low Basic Aluminum Chloride SolutionsBasic aluminum chloride solutions of low basicity were prepared by different methods and investigated by means of the ferrone kinetics. In solutions prepared by expulsion of hydrogen chloride or addition of solid sodium carbonate preferably dimeric cations are formed. In solutions prepared by addition of sodium hydroxide solution or sodium carbonate solution only at very low basicity small quantities of dimeric ions are formed, at increasing basicity tridecameric ions arise. An explanation of this behaviour is given, involving the action of hydroxide ions and a possible formation of the dihydroxy-aluminum complex. The rate constant for the reaction of the dimeric ions with the ferrone reagent was determined to be k = 0.97 ± 0.06 min-1.
    Notes: Basische Aluminiumchloridlösungen niedriger Basizitätsgrade wurden nach unterschiedlichen Verfahren dargestellt und mit Hilfe der Kinetik der Umsetzung mit Ferronreagenzlösung untersucht. Während bei der Darstellung durch Austreiben von Chlorwasserstoff und der Zugabe von festem Natriumcarbonat bevorzugt dimere Kationen gebildet werden, entstehen bei Zugabe von Natronlauge oder Natriumcarbonatlösung nur bei sehr kleinen Basizitätsgraden geringe Mengen an dimeren Ionen, bei Erhöhung der Basizität werden tridekamere Aluminiumionen gebildet. Eine Erklärung des Verhaltens wird über die Wirkung der Hydroxidionen und eine mögliche Bildung des Dihydroxoaluminiumkomplexes gegeben. Die Reaktionsgeschwindigkeitskonstante der dimeren Ionen mit Ferronreagenzlösung wurde zu k = 0,97 ± 0,06 min-1 bestimmt.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Basic Aluminium Salts and their Solutions. XIX. Nature of Aluminium Cations in Highly Basic Highly Concentrated Aluminium Chloride SolutionsIt is shown that in highly concentrated basic aluminium chloride solutions (cAl ≈ 7.7 mol · l-1; r = OH/Al = 2.48), prepared by dissolving aluminium metal in substoichiometric quantities of hydrochloric acid, polymeric aluminium cations (Alpoly) dominate. By dilution of these solutions also increasing amounts of monomeric cations (Almono) occur. On aging Almono reacts with Alpoly forming small portions of tridecameric Al13O40 cations (Al13).On the basis of these results literature data, after which corresponding commercial basic aluminium chloride solutions contain essentially Al13 cations, are critically discussed.
    Notes: Es wird gezeigt, daß in hochkonzentrierten basischen Aluminiumchloridlösungen (cAl ≈ 7,7 mol · l-1; r = OH/Al = 2,48), hergestellt durch Umsetzen von metallischem Al mit einem Unterschuß an Salzsäure, überwiegend polymere Aluminiumkationen (Alpoly) vorliegen. Bei Verdünnung der Lösungen treten daneben zunehmend monomere Kationen (Almono) auf, die im Verlaufe der Alterung mit dem Alpoly unter Bildung geringer Anteile von tridekameren Al13O40-Kationen (Al13) reagieren.Ausgehend von diesen Befunden werden Literaturangaben, wonach in kommerziellen basischen Aluminiumchloridlösungen entsprechender Konzentration und Basizität im wesentlichen Al13-Kationen auftreten sollen, einer kritischen Wertung unterzogen.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Basic Aluminium Salts and their Solutions. VI. Preparation and Characterization of a Water-soluble Al13O40 ChlorideThe water-soluble chloride is prepared from the sparingly soluble basic aluminium sulfate [Al13O4(OH)25(H2O)11](SO4)3 · xH2O by reaction with barium chloride. From kinetic and 27Al NMR measurements is concluded, that the solid chloride as well as its aqueous solution contain exclusively the Al13O40 cation. It is shown by differential thermal analysis that the solid chloride includes water in different linkage.
    Notes: Aus dem in Wasser schwer löslichen basischen Aluminiumsulfat [Al13O4(OH)25(H2O)11](SO4)3 · xH2O wird durch Umsetzung mit Bariumchlorid das gut wasserlösliche Chlorid hergestellt. Aus kinetischen Untersuchungen und 27Al-Kernresonanz-Messungen wird geschlossen, daß sowohl das feste basische Chlorid als auch seine wäßrige Lösung ausschließlich das Al13O40-Kation enthalten. Die Differentialthermoanalyse des festen Chlorids zeigt, daß Wasser in unterschiedlichen Bindungszuständen vorliegt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Basic Aluminium Salts and their Solutions. XII. Comparative Studies of Basic Aluminium Chloride Solutions Prepared in Different WaysBasic aluminum chloride solutions were prepared from solutions of the neutral salt by adding alkali or by dissolution of metallic aluminum. The solutions prepared by both methods contain monomeric, tridecameric, and polymeric aluminum cations, as was shown by the ferrone method and by 27Al NMR spectroscopy. The formation of tridecameric ions is favoured by low temperature, low basicity, and in diluted solution; at higher temperatures and basicities they are transformed to polymeric and monomeric forms.
    Notes: Basische Aluminiumchloridlösungen wurden aus Lösungen des neutralen Salzes durch Zugabe von Lauge bzw. Auflösen von metallischem Aluminium hergestellt. Ihre Untersuchung mit der Ferronmethode und der 27Al-Kernresonanz ergab in den Lösungen beider Darstellungsarten monomere, tridekamere und polymere Aluminiumkationen. Die tridekameren Ionen bilden sich bevorzugt bei niedriger Temperatur, geringen Basizitätsgraden und in verdünnter Lösung. Bei höheren Temperaturen und Basizitätsgraden werden sie in polymere und monomere Aluminiumformen umgewandelt.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 603 (1991), S. 129-135 
    ISSN: 0044-2313
    Keywords: Intercalation ; heteropoly cations ; pillared clays ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Intercalation of Heteropoly Cations into the Interlayer Space of SmectitesIn difference to [GeO4Al12(OH)24(H2O)12]8+ (GeAl12) the intercalation of [AlO4Al12(OH)24(H2O)12]7+ (Al13) and [GaO4Al12(OH)24(H2O)12]7+ (GaAl12) cations causes the formation of pillared clays. The reason for this different behaviour is investigated by the “Ferron”-method. The Al13 cation is stable during the pillaring process. GeAl12 undergoes protolysis and transformation into polymeric cations of unknown structure, which do not form pillared clays. The phenomenon of formation of polymeric species could be shown for GaAl12 in a small amount without influence on the formation of pillared clays.
    Notes: Der Einbau der Kationen [AlO4Al12(OH)24(H2O)12]7+ (Al13) und [GaO4Al12(OH)24(H2O)12]7+ (GaAl12) in Smectite führt im Gegensatz zum [GeO4Al12(OH)24(H2O)12]8+ (GeAl12) zur pillared clay-Bildung. Mittels der Ferronmethode werden die Ursachen für dieses unterschiedliche Verhalten untersucht. Das Al13-Kation ist während des pillaring-Prozesses als stabil anzusehen. Beim GeAl12 erfolgt nach Protolyse eine Umwandlung in polymere Kationen unbekannter struktur, die nicht zur pillared clay-Bildung befähigt sind. Das Phänomen der Bildung polymerer Species tritt beim GaAl12 nur im geringen Umfang auf und hat keine Auswirkungen auf die Produktbildung.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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