Quininium (R)-mandelate, a structure with large Z′ described as an incommensurately modulated structure in (3+1)-dimensional superspace

Andreas Schönleber, Gervais Chapuis
  • Acta Crystallographica Section B Structural Science, January 2004, International Union of Crystallography
  • DOI: 10.1107/s0108768103027605

Incommensurately modulated structure of quininium (R)-mandelate

What is it about?

Quininium (R)-mandelate is an organic salt with an incommensurately modulated structure at room temperature. The large number of first- and second-order satellite reflections with relatively strong intensities indicates a significant modulation, because of which no average structure solution could be obtained. Hence the structure solution was performed in two suitable superstructure approximations.

Why is it important?

Positional modulation functions and modulation functions for the anisotropic atomic displacement parameters were introduced. The modulation originates from a competition between intramolecular and intermolecular forces, which is reflected, in the superspace formalism, in the modification of hydrogen bonds along the internal space variable t.

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http://dx.doi.org/10.1107/s0108768103027605

The following have contributed to this page: Priv.-Doz. Dr. Andreas Schönleber