Re-refinement of sodium ammonium sulfate dihydrate at 170 K

Tamira Eckhardt; Christoph Wagner; Peter Imming; Rüdiger W Seidel

doi:10.1107/S2414314620012754

Re-refinement of sodium ammonium sulfate dihydrate at 170 K

IUCrdata. 2020 Sep 25;5(Pt 9):x201275. doi: 10.1107/S2414314620012754. eCollection 2020 Sep.

Authors

Tamira Eckhardt¹, Christoph Wagner², Peter Imming¹, Rüdiger W Seidel¹

Affiliations

¹ Institut für Pharmazie, Wolfgang-Langenbeck-Str. 4, 06120 Halle (Saale), Germany.
² Institut für Chemie, Kurt-Mothes-Str. 2, 06120 Halle (Saale), Germany.

Abstract

The title compound, sodium ammonium sulfate dihydrate (SASD), NaNH₄SO₄·2H₂O, a synthetic analogue of the mineral lecontite, is a well known ferroelectric. The crystal structure of the paraelectric phase has been re-refined at 170 K on the basis of single-crystal X-ray data, improving the previous study [Arzt & Glazer (1994 ▸). Acta Cryst. B50, 425-431] in terms of accuracy regarding hydrogen-atom positions and thus details of the hydrogen bonding. O-H⋯O and N-H⋯O hydrogen bonds between the principal building units [Na(OH₂)₄O₂ octa-hedra, SO₄ tetra-hedra and ammonium cations] constitute a three-dimensional network structure.

Keywords: chain structure; chirality; crystal structure; ferroelectric; hydrogen bonding; sulfate mineral.

Grants and funding

We acknowledge the financial support within the funding programme Open Access Publishing by the German Research Foundation (DFG).