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Updated: May 27, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Tetra-n-butyl-ammonium bromide: a redetermination at 150 K addressing the merohedral twinning
1Chemistry Department, Loughborough University, Loughborough, LE11 3TU, England.
Abstract:
The redetermined, low temperature (150 K), structure of tetra-n-butyl-ammonium bromide, (C(4)H(9))(4)N(+)·Br(-), has been found to be merohedrally twinned via twin law -1 0 0, 0 - 1 0, 1 0 1. The structure was previously determined, with low precision, no inclusion of H atoms and only the bromide ion refined with anisotropic displacement parameters, by Wang et al. (1995 ▶). Mol. Cryst. Liq. Cryst. Sci. Tech. A, 264, 115-129. The redetermined structure has considerably improved precision in all geometrical parameters, has all non-H atoms refined anisotropically, H atoms included, and is isomorphous with the iodide analogue. The structure is otherwise routine, with the shortest cation to anion contacts being between the bromide anion and the CH atoms close to the ammonium nitro-gen centre at a distance of ca. 2.98-3.11 Å. Each anion makes eight such contacts to four different anions. The n-butyl chains are fully extended, adopting an all-anti conformation with approximate S(4) point symmetry.
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