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Phase transition and structures of the twinned low‐temperature phases of (Et 4 N)[ReS 4 ]
Author(s) -
Bernhardt Eduard,
Herbst-Irmer Regine
Publication year - 2020
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s205322961901725x
Subject(s) - monoclinic crystal system , phase (matter) , metastability , crystal twinning , phase transition , crystallography , materials science , space group , crystal structure , condensed matter physics , chemistry , x ray crystallography , physics , optics , diffraction , microstructure , organic chemistry
The title compound, tetraethylammonium tetrathiorhenate, [(C 2 H 5 ) 4 N][ReS 4 ], has, at room temperature, a disordered structure in the space group P 6 3 mc ( Z = 2, α‐phase). A phase transition to the monoclinic space group P 2 1 ( Z = 2, γ‐phase) at 285 K leads to a pseudo‐merohedral twin. The high deviation from the hexagonal metric causes split reflections. However, the different orientations could not be separated, but were integrated using a large integration box. Rapid cooling to 110–170 K produces a metastable β‐phase ( P 6 3 , Z = 18) in addition to the γ‐phase. All crystals of the β‐phase are contaminated with the γ‐phase. Additionally, the crystals of the β‐phase are merohedrally twinned. In contrast to the α‐phase, the β‐ and γ‐phases do not show disorder.