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  • 1
    Electronic Resource
    Electronic Resource
    Über Oxidhydroxide des vierwertigen Mangans mit Schichtengitter. 1. Mitteilung. Natriummangan (II, III)manganat(IV) (1970)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 53 (1970), S. 209-220 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation of Na4Mn14O27, 9H2O (hitherto named manganomanganite or δ-MnO2) by oxidation of a fresh Mn(OH)2 suspension in aqueous NaOH by molecular oxygen, and its probable structure are described. It is a double layer manganate (IV) structure resembling other manganates such as chalcophanite. Orthorhombic unit cell parameters are, a0 = 8,54, b0 = 15,39, c0 = 14,26 Å. In diluted nitric acid topotactical transition to manganese (III) manganate (IV), Mn7O13.5H2O (unit cell: a0 = 2,84, c0 = 7,27 Å; primitively hexagonal), and by prolonged digestion to nsutite, γ-MnO2, occurs.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19700530203
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  • 2
    Electronic Resource
    Electronic Resource
    Über Oxidhydroxide des vierwertigen Mangans mit Schichtengitter 2. Mitteilung: Mangan (III)-manganat (IV) (1970)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 53 (1970), S. 453-464 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation and probable structure of managanese (III)-manganate (IV) Mn7O13, 5H2O (a0 = 2,84, c0 = 7,27 Å) and manganous (II)-manganate (IV) Mn7O12, 6H2O are described. Both consist of platelets. Digesting in diluted HNO3 leads to γ-MnO2 (nsutite). Manganese (III)-manganate (IV) is much less stable than the sodiummanganese (II, III)-manganate-(IV) described earlier and looses water easily when heated or in vacuo. Water loss results in breaking down of the double layer lattice, and the product is only two-dimensionally ordered, producing only prism reflections on the X ray diagramm. Heating results in a continuous transition to the two-dimensionally ordered phase, then to a finely divided and very disordered γ-MnO2, and eventually to a finely divided and disordered β-MnO2 (pyrolusite). The transition is topotactical so far, but further heating produces δ-Mn2O3 without obvious topotactical relations to the earlier products. The so-called ‘δ-MnO2’ (birnessite) appears to be a family of finely divided and very disordered varieties of such manganates (IV) with part of the Mn3+ substituted by Mn4+. Since such products usually contain remarkable amounts of alkali ions, they are rather varieties of the earlier described sodiummanganese (II, III)-manganate (IV). A provisional explanation of the streaking in the electron diffractions of these manganate (IV). A provisional explanation of the streaking in the electron diffractions of these manganates (IV) is given. With respect to these results the so-called ‘δ-MnO2’ can no longer be attributed to the true manganese dioxides.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19700530302
    Library Location Call Number Volume/Issue/Year Availability
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    Paper (German National Licenses)
    Fulltext
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