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Rotational Polymorphism of Methyl-Substituted Ammonium Perchlorates

  • M. Stammler
  • R. Bruenner
  • W. Schmidt
  • D. Orcutt

Abstract

The thermal transformations which take place in solid methyl-substituted ammonium perchlorates have been studied using high-temperature X-ray diffraction and differential thermal analysis techniques. In the temperature range from 20°C to their decomposition temperature (above 300°C), ammonium perchlorate and tetramethyl ammonium perchlorate undergo only one enantiomorphic phase transition, namely at 240 and 340°C (with decomposition), respectively. This I–II transition is ascribed to the beginning of the free rotation of the C104 ions. The rotation of the cations, however, begins below room temperature. If the symmetry of the cation is lowered by having both methyl groups and hydrogens arranged around the nitrogen (as in monomethyl, dimethyl, and trimethyl ammonium perchlorates), there is an additional enantiomorphic phase transition. This II–III transformation is ascribed to the rotation of the cations which have, in the partially substituted ions, two sets of non-equivalent symmetry axes (different moments of inertia). The temperatures of transformation are discussed in terms of the space requirements for rotation. Symmetries and cell dimensions of some modifications were determined.

Keywords

Ammonium Perchlorate Ammonium Perchlorate Dimethyl Ammonium Perchlorate Salt Tetragonal Unit Cell 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    D. Vorländer and E. Kaascht, “Neue Formen der überchlorsauren Salze,” Ber. deut. chem. Ges. 56B: 1157, 1923.CrossRefGoogle Scholar
  2. 2.
    W. Büssern and K. Herrmann, “Röntgenographische Untersuchung der einwertigen Perchlorate, Z. Krist. 67: 405, 1928.Google Scholar
  3. 3.
    H. Braekken and L. Harang, “Die kubische Hochtemperatur struktur einiger Perchlorate.” Z. Krist. 75: 538, 1930.Google Scholar
  4. 4.
    K. Herrmann and W. Ilge, “Röntgenographische Strukturerforschung der kubischen Modifikation der Perchlorate,” Z. Krist. 75: 41, 1930.Google Scholar
  5. 5.
    L. Pauling, “The Rotational Motion of Molecules in Crystals,” Phys. Rev. 36: 430, 1930.CrossRefGoogle Scholar
  6. 6.
    A. Eucken, “Rotation von Molekeln and Ionengruppen in Kristallen,” Z. Electrochem. 45: 126, 1939.Google Scholar
  7. 7.
    A. W. Lawson, “The Variation of the Adiabatic and Isothermal Elastic Moduli and Coefficient of Thermal Expansion with Temperature through the A-Point Transition of NH4C1,” Phys. Rev. 57: 417, 1940.CrossRefGoogle Scholar
  8. 8.
    J. Frenkel, “Über die Drehung von Dipolmolekülen in festen Körpern,” Acta Physicochem. U.R.S.S. 3: 23, 1935.Google Scholar
  9. 9.
    H. A. Levy and S. W. Peterson, presentation before the International Congress for Pure and Applied Chemistry, New York, 1951.Google Scholar
  10. 10.
    M. Stammler, D. Orcutt, and P. C. Colodny in: W. M. Mueller, G. R. Mallet, and M. J. Fay (eds.), Advances in X-Ray Analysis, Vol. 6, Plenum Press, New York, 1962, p. 202.Google Scholar
  11. 11.
    J. C. Petricciani, S. E. Weberly, W. H. Bauer and T. W. Clapper, J. Phys. Chem. 64: 1309, 1960.CrossRefGoogle Scholar
  12. 12.
    M. Stammler and D. Orcutt, in: W. M. Mueller, G. R. Mallett, and M. J. Fay (eds.), Advances in X-Ray Analysis, Vol. 5, Plenum Press, New York, 1961, p. 133.Google Scholar
  13. 13.
    J. W. Conant, L. L. Corrigan, and A. A. Sparks, “The Structure of Hydrazinium Fluoborate”, Acta Cryst. 17: 1085, 1964.CrossRefGoogle Scholar
  14. 14.
    K. C. Moss and D. W. A. Sharp, letter to the editor, J. Inorg. Nucl. Chem. 13: 328, 1960.CrossRefGoogle Scholar
  15. 15.
    Takeo Nagamiya, “Zur Theorie der Umwandlung der festen Ammoniumhalogenide bei tiefen Temperaturen,” Proc. Phys. Math. Soc. Japan, 25: 540, 1943.Google Scholar

Copyright information

© Springer Science+Business Media New York 1966

Authors and Affiliations

  • M. Stammler
    • 1
  • R. Bruenner
    • 1
  • W. Schmidt
    • 1
  • D. Orcutt
    • 1
  1. 1.Aerojet-General CorporationSacramentoUSA

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