Acta Cryst. (2002). E58, m416-m419  [ doi:10.1107/S160053680201214X ]

Bis(trimethylammonium) tetrachloromercurate(II) at 343 K

M. Amami, S. Van Smaalen and A. Ben Salah

Abstract: In order to investigate a possible phase transition at 324 K in the title compound, (NHMe₃)₂[HgCl₄], the crystal structures at 295 and 343 K have been determined, using restrictions of the non-crystallographic site symmetry of the trimethylammonium (TrMA) ions. The hydrogen-bond network, namely N-HCl, undergoes a considerable change, by a 38° rotation of one of the TrMA cations about the N-H bond axis. This transition is shown to be a non-symmetry-breaking structural transition, which corresponds to a gradual loss of the orientational order of the TrMA cations.

Online 19 July 2002

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